Patent Publication Number: US-2018051313-A1

Title: Methods, devices, and kits for detecting microorganisms in a fluid sample

Description:
FIELD 
     The present disclosure relates to methods of detecting microorganisms in a fluid sample and to devices and kits including the devices for use in detecting microorganisms. 
     BACKGROUND 
     Bacteria occur naturally in most aquatic systems and can cause problems in industrial and municipal applications using water such as cooling towers, heat exchangers, potable and wastewater applications, oil and gas exploration, and hydraulic fracturing operations. The bacteria need to be monitored to develop and implement an effective disinfection program to keep the bacteria within acceptable limits. The microbiological quality of water is typically assessed by traditional growth-based methods, which can take 24 to 48 hours to perform. Rapid methods based on ATP bioluminescence assays have been used to determine microbial contamination in water as they provide immediate results; however, the methods are limited by detection sensitivity because they require at least 1×10 5  colony forming units (cfu)/ml to elicit detectable responses. Interference from treatment chemicals or matrix components can affect the bioluminescence, leading to erroneous results and mismanagement of biocides, for instance. One can increase the sensitivity of the ATP bioluminescence assay by using a larger volume of sample (e.g., 100 ml), but such methods can be difficult to implement in the field. 
     SUMMARY 
     Devices and methods are provided that can be used to detect microorganisms in fluid samples, such as water or aqueous dispersions. 
     In a first aspect, a method of detecting microorganisms in a fluid sample is provided. The method includes providing a nonwoven article, providing a fluid sample suspected of containing at least one microorganism strain or target cellular analyte, and contacting the fluid sample with the nonwoven article such that at least a portion of the at least one microorganism strain or target cellular analyte is bound to the nonwoven article. The nonwoven article includes a fibrous porous matrix and a plurality of concentration agent particles enmeshed in the fibrous porous matrix. The method further includes placing the microorganism strain- or target cellular analyte-bound nonwoven article in contact with at least one detection reagent and detecting the presence of the bound microorganism strain or bound target cellular analyte. 
     In a second aspect, a device for contacting a fluid sample with a nonwoven article is provided. The device includes a sample container, a filter holder, a nonwoven article, and a first adaptor configured to interface the filter holder with a receptacle. The nonwoven article includes a fibrous porous matrix and a plurality of concentration agent particles enmeshed in the fibrous porous matrix. 
     In a third aspect, another device for contacting a fluid sample with a nonwoven article is provided. The device includes a sample container, a filter holder configured to interface with a receptacle, and a nonwoven article. The nonwoven article includes a fibrous porous matrix and a plurality of concentration agent particles enmeshed in the fibrous porous matrix. 
     In a fourth aspect, a kit is provided. The kit includes a device for contacting a fluid sample with a nonwoven article and a receptacle. The device includes a sample container, a filter holder, a nonwoven article, and a first adaptor. The first adaptor is configured to interface the filter holder with the receptacle. The nonwoven article includes a fibrous porous matrix and a plurality of concentration agent particles enmeshed in the fibrous porous matrix. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic side view of an exemplary sample container according to the disclosure. 
         FIG. 1B  is a schematic cross-sectional view of an exemplary filter holder according to the disclosure. 
         FIG. 1C  is a schematic top view of an exemplary nonwoven article according to the disclosure. 
         FIG. 1D  is a schematic end view of the filter holder of  FIG. 1B . 
         FIG. 1E  is a schematic side view of the container of  FIG. 1A  threaded onto the filter holder of  FIG. 1B , the filter holder containing the nonwoven article of  FIG. 1C . 
         FIG. 2A  a schematic side view of an exemplary sample container according to the disclosure. 
         FIG. 2B  is a schematic side view of an exemplary second adaptor according to the disclosure. 
         FIG. 2C  is a schematic side view of an exemplary filter holder threaded onto the second adaptor of  FIG. 2B  according to the disclosure. 
         FIG. 2D  is a schematic side view of the container of  FIG. 2A  threaded onto the filter holder and second adaptor combination of  FIG. 2C . 
         FIG. 2E  is a schematic side view of the device of  2 D attached to a stopper. 
         FIG. 3A  a schematic side view of an exemplary sample container according to the disclosure. 
         FIG. 3B  is a schematic side view of another exemplary second adaptor according to the disclosure. 
         FIG. 3C  is a schematic side view of an exemplary filter holder threaded onto the second adaptor of  FIG. 3B  according to the disclosure. 
         FIG. 3D  is a schematic side view of the container of  FIG. 3A  threaded onto the filter holder and second adaptor combination of  FIG. 3C . 
         FIG. 3E  is a schematic side view of the device of  2 D attached to a collection container. 
         FIG. 4A  is a schematic side view of a further exemplary device according to the disclosure. 
         FIG. 4B  is a schematic top view of the device of  FIG. 4A , further including an exemplary vacuum source. 
         FIG. 5  is a schematic side view of yet another exemplary device according to the disclosure. 
         FIG. 6  is an exploded perspective view of a sample preparation system according to one embodiment of the present disclosure, the sample preparation system including a lid. 
         FIG. 7A  is a schematic perspective view of another exemplary filter holder according to the disclosure. 
         FIG. 7B  is a schematic perspective view of an exemplary first adaptor according to the disclosure. 
         FIG. 7C  is a schematic perspective view of the filter holder of  FIG. 7A  containing a first adaptor and a nonwoven article according to the disclosure. 
         FIG. 7D  is a schematic perspective view of a sample delivery system according to the disclosure. 
         FIG. 7E  is a schematic side view of the filter holder of  FIG. 7C  containing the first adaptor of  FIG. 7B  and connected to the sample delivery system of  FIG. 7D . 
         FIG. 8A  is a schematic perspective view of a detection device handle being inserted into a filter holder according to the disclosure. 
         FIG. 8B  is a schematic perspective view of the detection device handle of  FIG. 8A  being removed from the filter holder and removing a first adaptor and nonwoven article with the handle. 
         FIG. 8C  is a schematic side view of the detection device handle of  FIG. 8B  being inserted in a detection device. 
         FIG. 8D  is a schematic side view of the detection device handle of  FIG. 8C  being completely inserted in the detection device. 
         FIG. 8E  is a schematic side view of the detection device of  FIG. 8D  operationally coupled to a luminometer. 
         FIG. 9A  is a schematic side view of a syringe adaptor. 
         FIG. 9B  is another schematic perspective view of a syringe adaptor. 
         FIG. 9C  is a schematic perspective view of a filter holder containing a first adaptor. 
         FIG. 9D  is a schematic perspective view of a filter holder containing a nonwoven article secured to a first adaptor with a gasket. 
         FIG. 9E  is a schematic perspective view of the syringe adaptor of  FIG. 9B  coupled to the filter holder of  FIG. 9D . 
         FIG. 9F  is a schematic side view of a device including a syringe, the syringe adaptor of  FIG. 9A , and the filter holder of  FIG. 9D . 
         FIG. 10A  is a schematic perspective view of a first filter holder portion. 
         FIG. 10B  is another schematic perspective view of a first filter holder portion. 
         FIG. 10C  is a schematic perspective view of a first adaptor. 
         FIG. 10D  is a schematic perspective view of the first filter holder portion of  FIG. 10B  containing the first adaptor of  FIG. 10C . 
         FIG. 10E  is a schematic perspective view of the first filter holder portion of  FIG. 10D  further containing a nonwoven article and a gasket. 
         FIG. 10F  is a schematic perspective view of a second filter holder portion. 
         FIG. 10G  is an exploded side view of a device according to the disclosure. 
         FIG. 10H  is a schematic side view of the assembled device of  FIG. 10G . 
         FIG. 11A  is a schematic perspective view of a detection device handle being removed from a first filter holder portion and removing a first adaptor and nonwoven article with the handle. 
         FIG. 11B  is a schematic side view of the detection device handle of  FIG. 11A  being inserted in a detection device. 
         FIG. 11C  is a schematic side view of the detection device handle of  FIG. 11B  being completely inserted in the detection device. 
     
    
    
     DETAILED DESCRIPTION 
     Rapid methods for monitoring of microbial quality of fluid samples are provided. The methods combine devices that concentrate at least one microorganism or target cellular analyte by a nonwoven article, and detection of the microorganism or target cellular analyte. Devices according to the disclosure enable contact with large volumes of fluid samples, and also allow further optional washing to remove contaminants prior to detection. The nonwoven article is easily transferred to a receptacle for detection. Methods according to the disclosure are capable of readily detecting bacterial contamination in water in about 15 minutes. Accordingly, the methods and devices are suitable for field based detection of microorganisms and target cellular analytes in fluid samples. 
     For the following Glossary of defined terms, these definitions shall be applied for the entire application, unless a different definition is provided in the claims or elsewhere in the specification. 
     Glossary 
     Certain terms are used throughout the description and the claims that, while for the most part are well known, may require some explanation. It should be understood that, as used herein: 
     The term “a”, “an”, and “the” are used interchangeably with “at least one” to mean one or more of the elements being described. 
     The term “and/or” means either or both. For example “A and/or B” means only A, only B, or both A and B. 
     As used in this specification, the recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.8, 4, and 5). 
     Unless otherwise indicated, all numbers expressing quantities or ingredients, measurement of properties and so forth used in the specification and embodiments are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached listing of embodiments can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings of the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claimed embodiments, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. 
     The terms “comprises” and variations thereof do not have a limiting meaning where these terms appear in the description and claims. 
     The words “preferred” and “preferably” refer to embodiments of the disclosure that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the disclosure. 
     Unless specified or limited otherwise, the terms “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect supports and couplings. It is to be understood that other embodiments may be utilized, and structural or logical changes may be made without departing from the scope of the present disclosure. Furthermore, terms such as “front,” “rear,” “top,” “bottom,” and the like are only used to describe elements as they relate to one another, but are in no way meant to recite specific orientations of the apparatus, to indicate or imply necessary or required orientations of the apparatus, or to specify how the invention described herein will be used, mounted, displayed, or positioned in use. 
     The term “cellular analyte” means an analyte of cellular origin (that is, a microorganism or a component thereof (for example, a cell or a cellular component such as deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), proteins, nucleotides such as adenosine triphosphate (ATP), and the like, and combinations thereof); references to a microorganism or microorganism strain throughout this specification are meant to apply more generally to any cellular analyte). 
     The term “concentration agent” means a material or composition that binds microorganisms and/or cellular analytes from a fluid sample (preferably, having a cellular analyte capture or binding efficiency of at least about 60 percent, or at least about 70 percent, or at least about 80 percent, or at least about 90 percent), thereby concentrating the microorganisms and/or cellular analytes into a smaller volume than when present in the fluid sample. 
     The term “detection” means the identification of a cellular analyte (for example, at least a component of a target microorganism, which thereby determines that the target microorganism is present). 
     The term “enmeshed” (in regard to particles in a fibrous porous matrix) means that the particles are entrapped in and on the fibrous porous matrix (and, preferably, distributed within it), rather than solely being borne on its surface. 
     The term “fibrillated” (in regard to fibers or fibrous material) means treated (for example, by beating) in a manner that forms fibrils or branches attached to a fiber&#39;s main trunk. 
     The term “fibrous porous matrix” means a nonwoven web or medium, (i.e., not a woven or knitted fabric), comprising interlaid fibers, for example, a web comprising fibers that are interlaid by meltblowing, spunbonding, or other air laying techniques; carding; wet laying; or the like. Typically, the fibers have lengths of less than 100 millimeters and are uncrimped. 
     The term “filtering” is generally used to describe the process of separating matter by size, charge and/or function. For example, filtering can include separating soluble matter and a solvent (e.g., diluent) from insoluble matter, or it can include separating soluble matter, a solvent and relatively small insoluble matter from relatively large insoluble matter. A variety of filtration methods can be used, including, but not limited to, passing the liquid composition through a filter, settling followed by aspiration or decanting, other suitable filtration methods, and combinations thereof. “Settling” is used to refer to allowing the insoluble matter in the liquid composition to settle. Settling may occur by gravity or by centrifugation. The insoluble matter (or relatively large insoluble matter) can then be separated from the soluble matter (or soluble matter and relatively small insoluble matter) and solvent by aspirating the soluble matter and solvent from the insoluble matter, decanting the soluble matter and solvent, or a combination thereof. 
     The term “filtrate” is generally used to describe the liquid remaining after the insoluble matter (or at least the relatively large insoluble matter) has been removed from the liquid composition. 
     The term “fluid” means liquid, solution, or dispersion of solid or liquid in liquid. 
     The term “microorganism” means any cell or particle having genetic material suitable for analysis or detection (including, for example, bacteria, yeasts, viruses, and bacterial endospores). 
     The term “microorganism strain” means a particular type of microorganism that is distinguishable through a detection method (for example, microorganisms of different genera, of different species within a genera, or of different isolates within a species). 
     The terms “polymer” and “polymeric material” are used interchangeably and refer to materials formed by reacting one or more monomers. 
     The term “sample” means a substance or material that is collected (for example, to be analyzed). 
     The term “sample matrix” means the components of a sample other than microorganisms and/or cellular analytes. 
     The term “target cellular analyte” means any cellular analyte that is desired to be detected. 
     The term “target microorganism” means any microorganism that is desired to be detected. 
     Reference throughout this specification to “one embodiment,” “certain embodiments,” “one or more embodiments” or “an embodiment,” whether or not including the term “exemplary” preceding the term “embodiment,” means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the certain exemplary embodiments of the present disclosure. Thus, the appearances of the phrases such as “in one or more embodiments,” “in some embodiments,” “in certain embodiments,” “in one embodiment,” “in many embodiments” or “in an embodiment” in various places throughout this specification are not necessarily referring to the same embodiment of the certain exemplary embodiments of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments. 
     Various exemplary embodiments of the disclosure will now be described. Exemplary embodiments of the present disclosure may take on various modifications and alterations without departing from the spirit and scope of the disclosure. Accordingly, it is to be understood that the embodiments of the present disclosure are not to be limited to the following described exemplary embodiments, but are to be controlled by the limitations set forth in the claims and any equivalents thereof. 
     In a first aspect, a method of detecting microorganisms in a fluid sample is provided. The method includes providing a nonwoven article, providing a fluid sample suspected of containing at least one microorganism strain or target cellular analyte, and contacting the fluid sample with the nonwoven article such that at least a portion of the at least one microorganism strain or target cellular analyte is bound to the nonwoven article. The nonwoven article includes a fibrous porous matrix and a plurality of concentration agent particles enmeshed in the fibrous porous matrix. The method further includes placing the microorganism strain- or target cellular analyte-bound nonwoven article in contact with at least one detection reagent and detecting the presence of the bound microorganism strain or bound target cellular analyte. 
     A variety of microorganisms can be concentrated and detected by using the methods of the disclosure, including, for example, bacteria, fungi, yeasts, protozoans, viruses (including both non-enveloped and enveloped viruses), fungal spores, bacterial endospores (for example,  Bacillus  (including  Bacillus anthracis, Bacillus cereus , and  Bacillus subtilis ) and  Clostridium  (including  Clostridium botulinum, Clostridium difficile , and  Clostridium perfringens )), and the like, and combinations thereof, such as gram-negative bacteria, gram-positive bacteria, yeasts, fungi, and combinations thereof. Target cellular analyte that can be concentrated and detected by using the methods of the disclosure include nucleic acids, proteins, adenosine triphosphate (ATP), or combinations thereof. 
     Capturing or binding of microorganisms, cellular analytes, or combinations thereof is accomplished by contacting a fluid sample with a nonwoven article. In certain embodiments, contacting comprises filtration of the fluid sample through the nonwoven article. In select embodiments, contacting comprises passing the fluid sample at least twice through the nonwoven article, such as by sending a filtrate through the nonwoven article a second time or by placing the nonwoven article into a volume of the fluid sample and agitating the fluid sample such that sample passes through the nonwoven article multiple times. The method optionally further comprises passing the fluid sample through a coarse filter prior to the contacting the fluid sample with the nonwoven article. The use of such a filter can remove particulates from the fluid sample that might otherwise clog the nonwoven article. Suitable coarse filters include for example and without limitation, filters comprising pore sizes of at least 1 micrometer, at least 5 micrometers, at least 10 micrometers, at least 25 micrometers, or at least 50 micrometers. 
     Advantageously, the nonwoven articles of the present disclosure require only a very low pressure differential across the nonwoven article to effectively pass a fluid sample through the nonwoven article. This characteristic is particularly beneficial in environments, for instance, in a field situation, and/or when no or low power pumps are available for transporting a fluid sample. 
     In an embodiment of the present disclosure, the contacting comprises passing the fluid sample through the laminated article at a pressure of 14.7 pounds per square inch (psi) (101.3 kilopascals (kPa)) or less, or 4.0 pounds per square inch (psi) (27.58 kilopascals (kPa)) or less, or 3.0 psi (20.68 kPa), or 2.0 psi (13.79 kPa), or 1.0 psi (6.9 kPa), or 0.9 psi (6.21 kPa), or 0.8 psi (5.52 kPa), or 0.7 psi (4.83 kPa), or 0.6 psi (4.14 kPa), or even 0.5 psi (3.45 kPa) or less, and at a pressure of at least 0.4 psi (2.76 kPa), or at least 0.5 psi (3.45 kPa). 
     In certain embodiments, the method further comprises washing the at least one microorganism strain- or target cellular analyte-bound nonwoven article prior to placing the at least one microorganism strain- or cellular analyte-bound nonwoven article in contact with at least one detection reagent. It has been discovered that contaminants such as residual sample matrix can be removed from the nonwoven article without significant loss of the bound or captured microorganisms and/or cellular analytes. In certain embodiments, washing includes for instance and without limitation, rinsing with sterile deionized water or bottled drinking water, or rinsing with aqueous salt or buffer solutions. Washing the nonwoven article tends to remove components that could otherwise interfere with detecting the presence of the bound microorganisms and/or cellular analytes, depending on the particular detection method employed. 
     In certain embodiments, placing the microorganism strain- or target cellular analyte-bound nonwoven article in contact with a reagent includes placing the nonwoven article in a receptacle that comprises a material through which a detection signal can be detected, wherein the receptacle contains at least one reagent. For instance, placing the microorganism strain- or target cellular analyte-bound nonwoven article in contact with a reagent optionally includes placing nonwoven the article in a receptacle configured to be operationally coupled to a luminometer, wherein the receptacle contains at least one reagent. Hence, in such an embodiment, detection is facilitated by disposing the receptacle in the luminometer for measurement of light generated from reaction of the bound microorganism strain and/or target cellular analyte with at least one reagent. Similarly, the receptacle can be interfaced with other types of equipment depending on the particular detection method. In certain embodiments, placing the microorganism strain- or target cellular analyte-bound nonwoven article in contact with a reagent includes pushing the nonwoven article into a receptacle containing the at least one reagent. It has been discovered that microorganism strain(s) and/or target cellular analyte(s) can be detected without requiring removal from being captured by the nonwoven article. The ability to detect microorganism strains and/or target cellular analytes attached to the nonwoven article is advantageous because it decreases the number of required method steps as compared to methods in which the microorganism strain(s) and/or target cellular analyte(s) need to be eluted from a nonwoven article prior to detection. Further, the nonwoven article concentrates the microorganism strains and/or target cellular analytes into the volume of the article, which is typically significantly smaller than the volume of the fluid sample contacted with the nonwoven article. 
     Microorganisms and/or cellular analytes that have been captured or bound (for example, by adsorption, absorption, or by sieving) by the nonwoven article can be detected by essentially any desired method that is currently known or hereafter developed. Such methods include, for example, culture-based methods, microscopy (for example, using a transmitted light microscope or an epifluorescence microscope, which can be used for visualizing microorganisms tagged with fluorescent dyes) and other imaging methods, immunological detection methods, and genetic detection methods. The detection process following microorganism and/or cellular analyte capture optionally can include washing to remove sample matrix components, staining, boiling or using elution buffers or lysis agents to release cellular analyte from the concentration device, or the like. 
     Immunological detection is detection of an antigenic material derived from a target organism, which is commonly a biological molecule (for example, a protein or proteoglycan) acting as a marker on the surface of bacteria or viral particles. Detection of the antigenic material typically can be by an antibody, a polypeptide selected from a process such as phage display, or an aptamer from a screening process. 
     Immunological detection methods are well-known and include, for example, immunoprecipitation and enzyme-linked immunosorbent assay (ELISA). Antibody binding can be detected in a variety of ways (for example, by labeling either a primary or a secondary antibody with a fluorescent dye, with a quantum dot, or with an enzyme that can produce chemiluminescence or a colored substrate, and using either a plate reader or a lateral flow device). 
     Detection can also be carried out by genetic assay (for example, by nucleic acid hybridization or primer directed amplification). The captured or bound microorganisms can be lysed to render their genetic material (e.g., cellular analytes) available for assay. Lysis methods are well-known and include, for example, treatments such as sonication, osmotic shock, high temperature treatment (for example, from about 50° C. to about 100° C.), and incubation with an enzyme such as lysozyme, glucolase, zymolose, lyticase, proteinase K, proteinase E, and viral enolysins. 
     Many commonly-used genetic detection assays detect the nucleic acids of a specific microorganism, including the DNA and/or RNA. The stringency of conditions used in a genetic detection method correlates with the level of variation in nucleic acid sequence that is detected. Highly stringent conditions of salt concentration and temperature can limit the detection to the exact nucleic acid sequence of the target. Thus microorganism strains with small variations in a target nucleic acid sequence can be distinguished using a highly stringent genetic assay. Genetic detection can be based on nucleic acid hybridization where a single-stranded nucleic acid probe is hybridized to the denatured nucleic acids of the microorganism such that a double-stranded nucleic acid is produced, including the probe strand. One skilled in the art will be familiar with probe labels, such as radioactive, fluorescent, and chemiluminescent labels, for detecting the hybrid following gel electrophoresis, capillary electrophoresis, or other separation method. 
     Particularly useful genetic detection methods are based on primer directed nucleic acid amplification. Primer directed nucleic acid amplification methods include, for example, thermal cycling methods (for example, polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR), and ligase chain reaction (LCR)), as well as isothermal methods and strand displacement amplification (SDA) (and combinations thereof; preferably, PCR or RT-PCR). 
     Methods for detection of the amplified product are not limited and include, for example, gel electrophoresis separation and ethidium bromide staining, as well as detection of an incorporated fluorescent label or radio label in the product. Methods that do not require a separation step prior to detection of the amplified product can also be used (for example, real-time PCR or homogeneous detection). 
     Bioluminescence detection methods are well-known and include, for example, adensosine triphosphate (ATP) detection methods including those described in U.S. Pat. No. 7,422,868 (Fan et al.). Bioluminescence detection methods for ATP often include the known luciferin-luciferase system in which luciferase enzyme catalyzes the oxidation of luciferin in the presence of ATP and a divalent cation (such as magnesium or calcium). Other luminescence-based detection methods can also be utilized. 
     In many embodiments, detection comprises a culture-based detection method, an imaging detection method, a fluorescence-based detection method, a colorimetric detection method, an immunological detection method, a genetic detection method, a bioluminescence-based detection method, or a combination thereof. 
     As noted above, the nonwoven article comprises 1) a fibrous porous matrix and 2) a plurality of concentration agent particles enmeshed in the fibrous porous matrix. The nonwoven, fibrous porous matrix is often in the form of a layer of interlaid fibers that are not woven or knitted together. The nonwoven, fibrous porous matrix can be prepared by any suitable process such as, for example, air laying techniques, spunlaid techniques such as meltblowing or spunbonding, carding, wetlaying, and combinations thereof. In many embodiments, the fibrous nonwoven matrix is prepared by wetlaid techniques. 
     Fibers suitable for use in preparing the nonwoven fibrous porous matrix are usually pulpable or extrudable fibers such as those that are stable to radiation and/or to a variety of solvents. Optionally, at least some of the polymeric fibers can be selected to exhibit a degree of hydrophilicity. Useful fibers include polymeric fibers, inorganic fibers, and combinations thereof. More particularly, the fibers include a plurality of different types of fibers, including polyolefin fibers and fiberglass fibers. 
     Suitable polymeric fibers include those made from natural polymers (those derived from animal or vegetable sources) and/or synthetic polymers, including thermoplastic and solvent-dispersible polymers. Useful polymers include polyolefins (for example, poly(ethylene) (e.g., low density polyethylene, medium density polyethylene, high density polyethylene, etc.), polypropylene, poly(1-butene), copolymers of ethylene and propylene, alpha olefin copolymers such as copolymers of ethylene or propylene with 1-butene, 1-hexene, 1-octene, and 1-decene such as poly(ethylene-co-1-butene), poly(ethylene-co-1-butene-co-1-hexene), and the like); polylactic acid; poly(isoprenes); poly(butadienes); polyamides (for example, nylon 6, nylon 6,6, nylon 6,12, poly(iminoadipoyliminohexamethylene), poly(iminoadipoyliminodecamethylene), polycaprolactam, and the like); polyimides (for example, poly(pyromellitimide) and the like); polyethers; poly(ether sulfones) (for example, poly(diphenylether sulfone), poly(diphenylsulfone-co-diphenylene oxide sulfone), and the like); poly(sulfones); poly(vinyl esters) such as poly(vinyl acetates); copolymers of vinyl acetate (for example, poly(ethylene-co-vinyl acetate), copolymers in which at least some of the acetate groups have been hydrolyzed to provide various poly(vinyl alcohols) including poly(ethylene-co-vinyl alcohol), and the like); poly(phosphazenes); poly(vinyl ethers); poly(vinyl alcohols); polyaramids (for example, para-aramids such as poly(paraphenylene terephthalamide) and fibers sold under the trade designation “KEVLAR” by DuPont Co., Wilmington, Del., pulps of which are commercially available in various grades based on the length of the fibers that make up the pulp such as, for example, “KEVLAR 1F306” and “KEVLAR 1F694”, both of which include aramid fibers that are at least 4 mm in length; and the like); wool; silk; cellulosic polymers (for example, cellulose, cellulose derivatives such as rayon, and the like); acrylic polymers (for example, polyacrylonitrile); polyesters (for example, polyethylene terephthalate); fluorinated polymers (for example, poly(vinyl fluoride), poly(vinylidene fluoride), copolymers ofvinylidene fluoride such as poly(vinylidene fluoride-co-hexafluoropropylene), copolymers of chlorotrifluoroethylene such as poly(ethylene-co-chlorotrifluoroethylene), and the like); chlorinated polymers; poly(carbonates); and the like; and combinations thereof. In certain embodiments, the polymeric fibers comprise a polyolefin, a polysulfone, a polyamide, or a combination thereof. 
     Suitable inorganic fibers include those that contain at least one inorganic material selected from glasses, ceramics, and combinations thereof. These fibers are often added to provide strength to the fibrous porous matrix. For example, porous matrix layers containing inorganic fibers are often capable of being bent, folded, or pleated without breaking apart. Useful inorganic fibers include, for example, fiberglass (for example, E-glass, S-glass, and the like), ceramic fibers (for example, fibers made of metal oxides (such as alumina), silicon carbide, boron nitride, boron carbide, and the like), and combinations thereof. Useful ceramic fibers can be at least partially crystalline (exhibiting a discernible X-ray powder diffraction pattern or containing both crystalline and amorphous (glass) phases). In some applications, the inorganic fibers include fiberglass. 
     To facilitate entrapment of the concentration agent particles and/or to ensure a high surface area, the fibers used to form the nonwoven, fibrous porous matrix often contain at least one fibrillated fiber (for example, in the form of a main fiber surrounded by many smaller attached fibrils). The main fiber generally can have a length in the range of 0.5 millimeters to 5 millimeters and a diameter in a range of 1 micrometer to 20 micrometers. The fibrils typically can have a sub-micrometer diameter. In many embodiments, the fibrillated fibers are prepared from a polyolefin such as poly(ethylene) or polypropylene, or from an acrylic polymer such as polyacrylonitrile. 
     Suitable polymeric fibers further include bi-component fibers, which typically assist in binding all of the matrix fibers together due to a difference in melting point of one of the materials in the bi-component fiber. Bi-component fibers can have, for example, a core-sheath structure, a side-by-side structure, an islands-in-the-sea structure, or a segmented-pie structure, or the like. An example side-by-side bi-component fiber is the polyolefin thermally bonded bi-component fiber that is commercially available from Chisso Corporation (Osaka, Japan) under the trade designation CHISSO (for example, CHISSO ES). An example core-sheath bi-component fiber is commercially available from Unitika Ltd. (Osaka, Japan) under the trade designation MELTY (for example, MELTY 4080) and those commercially available from Minifibers, Inc. (Johnson City, Tenn.) made of ethyl vinyl acetate (sheath) and polypropylene (core), or made of a co-polyester of polyester and polyethylene terephthalate (PET) (sheath) and polyester (core). 
     The nonwoven fibrous porous matrix contains a plurality of different types of fibers. In some embodiments, the porous matrix can be formed using three, four, or even more different types of fibers. For example, a fiberglass fiber can be added for strength and integrity, while fibrillated poly(ethylene) can be added for entrapment of the particulates. Additionally, nylon fibers provide hydrophilic character while fibrillated poly(ethylene) fibers provide hydrophobic character to the porous matrix. If fibrillated and non-fibrillated fibers are used in combination, the weight ratio of fibrillated fibers to non-fibrillated fibers is often at least 1:2, at least 1:1, at least 2:1, at least 3:1, at least 5:1, or even at least 8:1. In some embodiments, mixtures of hydrophobic and hydrophilic polymeric fibers are used. For example, the fibrous porous matrix can include a mixture ofhydrophobic fibers such as polyolefins plus hydrophilic fibers such as polysulfones. In some specific examples, the polymeric fibers include polyolefin fibers, bi-component fibers, and fiberglass fibers. 
     In certain embodiments, the fibrous porous matrix is free ofpolyamide fibers. It has been discovered that the inclusion of nylon fibers in the fibrous porous matrix can result in lower luminescence than the fibrous porous matrix without the nylon fibers for a bioluminescent ATP detection method, as discussed in the Examples below. 
     Preferably, the fibers used to form the nonwoven fibrous porous matrix are uncrimped. In contrast to uncrimped fibers, crimped fibers may be identified as displaying repeating features (as manifested e.g., in a wavy, jagged, sinusoidal, etc., appearance of the fiber), by having a helical appearance (e.g., particularly in the case of crimped fibers obtained by thermal activation of bi-component fibers), and the like, and are readily recognizable by those of ordinary skill in the art. 
     Exemplary crimped fibers are described in U.S. Pat. No. 4,118,531 to Hauser and U.S. Pat. No. 5,597,645 to Pike et al., and CA Patent 2612854 to Sommer et al. 
     The fibers used to form the nonwoven fibrous porous matrix can be of a length and diameter that can provide a porous matrix having sufficient structural integrity and sufficient porosity for a particular application (for example, passing a fluid sample through the matrix). The fiber lengths are often at least about 0.5 millimeter, at least 1 millimeter, at least 2 millimeters, at least 3 millimeters, at least 4 millimeters, at least 6 millimeters, at least 8 millimeters, at least 10 millimeters, at least 15 millimeters, or at least 20 millimeters, and up to 50 millimeters, up to 40 millimeters, up to 30 millimeters, or up to 25 millimeters. The diameter of the fibers can be, for example, at least 10 micrometers, at least 20 micrometers, or at least 30 micrometers. The fiber lengths and diameters will vary depending upon factors such as the nature of the fiber and the type of application. 
     The nonwoven fibrous porous matrix often includes a mixture ofpolyolefin fibers, glass fibers, and bi-component fibers. In some particular embodiments, the nonwoven fibrous porous matrix contains a mixture of fibrillated polyethylene fibers, glass fibers, and sheath-core bi-component fibers. In some examples, the nonwoven fibrous porous matrix contains 40 to 80 weight percent fibrillated polyethylene fibers, 5 to 20 weight percent glass fibers, and 5 to 20 weight percent bi-component fibers. In some examples, the nonwoven fibrous porous matrix contains 40 to 80 weight percent fibrillated polyethylene fibers, 10 to 30 weight percent nylon fibers, 5 to 20 weight percent glass fibers, and 5 to 20 weight percent bi-component fibers. In other examples, the nonwoven, fibrous porous matrix contains 50 to 70 weight percent fibrillated polyethylene fibers, 5 to 15 weight percent glass fibers, and 5 to 20 weight percent bi-component fibers. In still other examples, the fibrous porous matrix contains 55 to 65 weight percent fibrillated polyethylene fibers, 0 to 20 weight percent nylon fibers, 5 to 15 weight percent glass fibers, and 10 to 20 weight percent bi-component fibers. 
     In most embodiments, the fibrous porous matrix contains only fibers. For example, at least 90 weight percent, at least 95 weight percent, at least 98 weight percent, at least 99 weight percent, or at least 99.5 weight percent of a dry fibrous porous matrix is fibers. In certain embodiments, the nonwoven article comprises a thickness of at least 0.1 millimeters, or at least 0.15 millimeters, or at least 0.2 millimeters, or at least 0.3 millimeters, or at least 0.4 millimeters, or at least 0.5 millimeters, or at least 0.6 millimeters. The nonwoven article usually comprises a thickness of up to 1 millimeter, or up to 0.9 millimeters, or up to 0.8 millimeters, or up to 0.7 millimeters, or up to 0.55 millimeters. Stated differently, the nonwoven article may comprise a thickness of between 0.15 millimeters and 1 millimeter, or between 0.15 millimeters and 0.8 millimeters, or between 0.1 millimeters and 0.7 millimeters. In certain embodiments, a nonwoven article having a thickness towards the lower end of the thickness range is selected to minimize interference with detection of the microorganisms and/or cellular analytes, such as decreasing time required for a reagent to diffuse into the nonwoven article, or decreasing blockage of a generated detection signal. 
     The nonwoven article typically includes both the fibrous porous matrix and concentration agent particles distributed within the fibrous porous matrix. In most embodiments, the nonwoven article contains at least 10 weight percent concentration agent particles based on a total dry weight of the nonwoven article. If the amount of the concentration agent particles is lower than about 10 weight percent, the nonwoven article may not contain enough concentration agent particles to effectively capture microorganisms or cellular analytes from a fluid sample. In some examples, the nonwoven article contains at least 15 weight percent, at least 20 weight percent, at least 25 weight percent, or at least 30 weight percent concentration agent particles based on a total dry weight of the nonwoven article. 
     On the other hand, the nonwoven article usually contains no greater than 55 weight percent concentration agent particles based on the total dry weight of the nonwoven article. If the amount of the concentration agent particles is greater than about 55 weight percent, the nonwoven article may contain an insufficient amount of the fibrous porous matrix. That is, the strength of the nonwoven article may be insufficient to hold together when employed to capture microorganism strains and/or target cellular analytes. In some examples, the nonwoven article contains no greater than 50 weight percent, no greater than 45 weight percent, or no greater than 40 weight percent concentration agent particles based on a total weight of the nonwoven article. 
     Stated differently, the nonwoven article often contains 10 to 55 weight percent concentration agent particles and 45 to 90 weight percent fibrous porous matrix, 15 to 50 weight percent concentration agent particles and 50 to 85 weight percent fibrous porous matrix, 20 to 50 weight percent concentration agent particles and 50 to 80 weight percent fibrous porous matrix, 20 to 45 weight percent concentration agent particles and 55 to 80 weight percent fibrous porous matrix, 25 to 40 weight percent concentration agent particles and 60 to 75 weight percent fibrous porous matrix, or 30 to 40 weight percent concentration agent particles and 60 to 70 weight percent fibrous porous matrix. The amounts are based on the total dry weight of the nonwoven article. 
     In many embodiments, the nonwoven article (when dry) contains only concentration agent particles and fibrous porous matrix. For example, the nonwoven article contains at least 90 weight percent, at least 95 weight percent, at least 98 weight percent, at least 99 weight percent, or at least 99.5 weight percent combined concentration agent particles and fibrous porous matrix when dry. 
     Concentration agent particles are water-insoluble particulate materials that have been employed to non-specifically capture microorganism strains, cellular analytes, or a combination thereof, when contacted with fluid samples containing microorganisms and/or cellular analytes. 
     The concentration agent particles typically comprise microparticles. The concentration agent particles typically comprise particles selected from the group consisting of amorphous metal silicates, guanidine-functionalized metal silicates, diatomaceous earth, surface-modified diatomaceous earth, guanidine-functionalized diatomaceous earth, gamma-FeO(OH), metal carbonates, metal phosphates, silica, perlite, guanidine-functionalized perlite, and combinations thereof. 
     In an embodiment, the concentration agent particles comprise particles of amorphous metal silicates, such as amorphous, spheroidized magnesium silicate, amorphous, spherical aluminum silicate, or a combination thereof. Amorphous, at least partially fused particulate forms of metal silicate can be prepared by any of the known methods of melting or softening relatively small feed particles (for example, average particle sizes up to about 25 micrometers) under controlled conditions to make generally ellipsoidal or spheroidal particles (that is, particles having magnified two-dimensional images that are generally rounded and free of sharp corners or edges, including truly or substantially circular and elliptical shapes and any other rounded or curved shapes). Such methods include atomization, fire polishing, direct fusion, and the like. A preferred method is flame fusion, in which at least partially fused, substantially glassy particles are formed by direct fusion or fire polishing of solid feed particles (for example, as in the method described in U.S. Pat. No. 6,045,913 (Castle et al.). Most preferably, such methods can be utilized to produce amorphous, spheroidized metal silicates by converting a substantial portion of irregularly-shaped feed particles (for example, from about 15 to about 99 volume percent; preferably, from about 50 to about 99 volume percent; more preferably, from about 75 to about 99 volume percent; most preferably, from about 90 to about 99 volume percent) to generally ellipsoidal or spheroidal particles. 
     Some amorphous metal silicates are commercially available. For example, amorphous, spheroidized magnesium silicate was commercially available for use in cosmetic formulations (for example, “3M COSMETIC MICROSPHERES CM-111”, available from 3M Company, St. Paul, Minn.). 3M COSMETIC MICROSPHERES CM-111 have a particle density of 2.3 g/cc, a surface area of 3.3 m 2 /g, and have a particle size of: 90 percent less than 11 microns (i.e., D 90 =11), 50 percent less than 5 microns, and 10 percent less than 2 microns. Amorphous aluminum silicate is commercially available for use in paints, primers, powder coatings, and other coatings, for example, “3M CERAMIC MICROSPHERES” from 3M Company, St. Paul, Minn. The 3M CERAMIC MICROSPHERES are alkali alumino silicate ceramic microspheres shaped as solid spheres with particle density of 2.4 g/cc, and are commercially available in three grades: W-210, W-410, and W-610. W-210 particles have a surface area of 5 m 2 /cc and a particle size of: 95 percent less than about 12 microns (i.e., D 95 =12), 90 percent less than about 9 microns, 50 percent less than about 3 microns, and 10 percent less than about 1 micron. W-410 particles have a surface area of 3 m 2 /cc and a particle size of: 95 percent less than about 24 microns (i.e., D 95 =24), 90 percent less than about 15 microns, 50 percent less than about 4 microns, and 10 percent less than about 1 micron. W-610 particles have a surface area of 3 m 2 /cc and a particle size of: 95 percent less than about 40 microns (i.e., D 95 =40), 90 percent less than about 28 microns, 50 percent less than about 10 microns, and 10 percent less than about 1 micron. 
     In certain embodiments, the concentration agent particles comprise perlite particles. 
     Perlite is a naturally-forming amorphous volcanic glass, containing about 70-75% silicon dioxide and 12-15% aluminum oxide, as well as smaller amounts of other metal oxides, including sodium oxide, potassium oxide, iron oxide, magnesium oxide, and calcium oxide. When perlite is expanded by heat it forms a lightweight aggregate. Examples of suitable perlite particles include the 4106 grade material, 4156 grade material and the 476 grade material, each commercially available from Dicaperl Minerals Corporation (Crawfordsville, Ind.). 
     In certain embodiments, the concentration agent particles comprise guanidine-functionalized metal silicate particles, guanidine-functionalized diatomaceous earth particles, or guanidine-functionalized perlite particles. A guanidine-functionalized particle can be made, for example, according to methods disclosed in commonly assigned International Application No. PCT/US2014/040861 (Kshirsagar et al.). A guanidine-functionalized metal silicate particle, guanidine-functionalized diatomaceous earth particle, or guanidine-functionalized perlite particle comprises at least one guanidine-containing ligand. The guanidine-containing ligand is formed by modifying the metal silicate, diatomaceous earth, or perlite particle with a guanidine-containing silane having the structure shown in Formula 1: 
       X 3-n R a   n Si—Y-G  Formula 1
 
     In Formula 1, Si is a silicon atom, and G denotes a guanidine group of the formula —NH—C(═NH)—NH 2 . Y is a divalent group that is covalently bonded to the silicon atom at one end and to the G group at the other end. Each R a  group, if any are present, is independently an alkyl, aralkyl, or aryl group, and is attached to the silicon atom. Each X is a leaving group covalently bonded to the silicon atom and is independently alkoxy or acyloxy, and n is 0, 1, or 2. A typical alkylene can be up to 20, up to 16, 12, 10, 8, 7, 6, 5, 4, or even up to 3 carbons, or even 2 carbons, inclusive of the terminal atoms of the divalent group. In some embodiments, Y is a divalent group comprising an alkylene of 3 to 6 carbons. In a preferred embodiment, Y is a divalent group having 3 carbons (i.e., propyl). 
     In Formula 1, each leaving group X is independently an alkoxy group of 1, 2, 3, 4, 5, 6, 7, 8, 9, or even up to 10 carbons, or is an acyloxy group of 2 carbons, or 3, 4, 5, 6, 7, 8, 9, or even up to 10 carbons, where the alkoxy or acyloxy group is bonded to the silicon through an oxygen atom. 
     In some embodiments, n is 0. When n is 0, no R a  groups are present, and Formula 1 can be re-written more simply as shown in Formula 2 (where Si, G, Y, and X are as defined for Formula 1): 
       X 3 Si—Y-G  Formula 2
 
     When the silane of Formula 1 (or Formula 2) reacts with an —OH group on the surface of a metal silicate or perlite particle, at least one X leaving group is replaced by a covalent bond of between the silicon atom and an oxygen atom on the surface of the metal silicate, diatomaceous earth, or perlite particle. An embodiment of a guanidine-functionalized metal silicate, guanidine-functionalized diatomaceous earth, or guanidine-functionalized perlite particle comprising a specific exemplary guanidine-containing ligand within the general type represented by Formula 1, wherein n=0 (i.e., as in Formula 2), is shown in Formula 3 (the circle in Formula 3 represents a metal silicate or perlite particle): 
     
       
         
         
             
             
         
       
     
     It will be understood that Formula 3 represents a specific embodiment wherein n is 3 and Y is a divalent group that is alkylene having 3 carbons. In each of Formulas 1 to 3, the ionization state of the guanidine group is omitted; however, it will be understood that in various environments such guanidine groups may be charged or uncharged (e.g., protonated or deprotonated), for example, according to the pH of a liquid medium in which the guanidine group is present. 
     The covalent bond(s) between the oxygen(s) of the ligand and the particle can be conveniently obtained, for example, by reacting a Si-bonded hydrolyzable group of the guanidine-containing precursor with a hydroxyl group of the particle. While the exemplary structure of Formula 3 shows three such bonded oxygen atoms (i.e., n=3 in Formula 1), it will be appreciated that in various embodiments one, two or three such bonded oxygen atoms can be provided. If less than three such oxygen atoms are bonded to the silicon atom, other substituents (e.g., substituents that are not bonded to the particle, and which are not shown in Formula 1) may be present on the silicon atom. For example, the guanidine-containing ligand can include a polymeric structure involving formation of Si—O—Si (i.e., siloxane) groups, resulting from Si—O bonds being formed between two or more guanidine-containing ligand precursors. Without being bound by theory, it is thought that Si—O—Si groups may form in the presence of added water, or other aqueous solvents, or other agent that can hydrolyze bonds in Si—O—R groups, to give rise to more complex guanidine-containing ligand structures attached to particles. 
     A network of polymerized guanidine-containing ligands can form a coating on the surface of the metal silicate, diatomaceous earth, or perlite particle. In some embodiments it may be desirable to obtain the particle functionalized with polymerized guanidine-containing ligand (e.g., having at least one Si—O—Si group in the polymerized guanidine-containing ligand), as a means of increasing the loading of nitrogen-containing guanidine groups on the surface of the metal silicate, diatomaceous earth, or perlite particle. It is thought that in at least these types of polymerizations, a loading of nitrogen-containing guanidine groups on the surface of the metal silicate or perlite particle can attain levels of surface nitrogen content in a range from 1 to 10 atomic percent, as can be measured, for example, by X-ray photoelectron spectroscopy. 
     Guanidine-functionalized particles of the present disclosure include metal silicate particles, diatomaceous earth particles, and perlite particles. Useful metal silicates include silicates of metals such as magnesium, calcium, zinc, aluminum, iron, titanium, and the like (preferably, magnesium and aluminum), and combinations thereof. Preferred are amorphous metal silicates in at least partially fused particulate form. In certain embodiments, more preferred are amorphous, spheroidized metal silicates; and even more preferably, amorphous, spheroidized magnesium silicate. In certain embodiments, more preferred are amorphous aluminum silicates. Metal silicates are known and can be chemically synthesized by known methods or obtained through the mining and processing of raw ores that are naturally-occurring. The metal silicate particle, such as a magnesium silicate particle, bears sufficient surface hydroxyl groups (typically, Si—OH groups) to enable a desired number of guanidine-containing ligands to be covalently attached thereto. Useful perlites include the 4106, 4156, and 476 grade materials from Dicaperl Minerals Corporation (Crawfordsville, Ind.). Useful diatomaceous earth particles can be obtained from natural sources, and are commercially available from Alfa Aesar (A Johnson Matthey Company, Ward Hill, Mass.). 
     The guanidine-functionalized metal silicate, diatomaceous earth, or perlite particles used in nonwoven articles of the present disclosure can be used in essentially any particulate form (preferably, a relatively dry or volatiles-free form) that is amenable to blending with fibers to form the nonwoven articles of the present disclosure. Preferably, the guanidine-functionalized particles are used in the form of a powder. Useful powders include those that comprise microparticles (preferably, microparticles having a particle size in the range of about 1 micrometer (more preferably, about 2 micrometers; even more preferably, about 3 micrometers; most preferably, about 4 micrometers) to about 100 micrometers (more preferably, about 50 micrometers; even more preferably, about 25 micrometers; most preferably, about 15 or 20 micrometers; where any lower limit can be paired with any upper limit of the range, as referenced above). 
     XPS is a technique that can provide information about the elemental and chemical (oxidation state and/or functional group) concentrations present on a solid surface. XPS typically provides an analysis of the outermost 3 to 10 nanometers (nm) of the specimen surface. XPS is sensitive to all elements in the periodic table except hydrogen and helium with detection limits for most species in the 0.1 to 1 atomic percent concentration range. In some cases, for example for CM-111 particles, a preferred surface composition assessment conditions for XPS can include a take-off angle of 90 degrees measured with respect to the sample surface with a solid angle of acceptance of 10 degrees. A person skilled in the art can select a suitable instrument setting for analysis of particles of the present disclosure. 
     In embodiments of the present disclosure, guanidine-functionalized metal silicate particles have a surface nitrogen content in a range from 1 atomic percent to 20 atomic percent, as measured by XPS. In some embodiments, the guanidine-functionalized metal silicate particles have a surface nitrogen content of at least 1 atomic percent, at least 2, at least 3, at least 4, or even at least 5 atomic percent, as measured by XPS. In some embodiments, the guanidine-functionalized metal silicate particles have a surface nitrogen content of up to 20 atomic percent, up to 15, up to 10, up to 9, up to 8, up to 7, or even up to 6 atomic percent, as measured by XPS. The surface nitrogen content of the guanidine-functionalized metal silicate particles, as measured by XPS, may be any combination of these lower and upper values, inclusive of the values thereof. A person skilled in the art would understand that in some embodiments it may be preferred to select higher or lower surface nitrogen content within these ranges, depending on the desired application. Suitable guanidine-functionalized perlite particles for use according to the present disclosure include those that comprise perlite and that have a surface composition having a surface nitrogen content of greater than 2 and less than or equal to about 12, as determined by XPS. Suitable guanidine-functionalized diatomaceous earth particles for use according to the present disclosure include those that comprise diatomaceous earth and have a surface composition having a surface nitrogen content of greater than 2 and less than or equal to about 12. 
     In some embodiments, particularly preferred are guanidine-functionalized magnesium silicate particles. Suitable guanidine-functionalized magnesium silicate particles for use according to the present disclosure include those that comprise an amorphous magnesium silicate and that have a surface composition having a metal atom to silicon atom ratio greater than 0.01 and less than or equal to about 0.5 (preferably, less than or equal to about 0.4; more preferably, less than or equal to about 0.3; most preferably, less than or equal to about 0.2), as determined by X-ray photoelectron spectroscopy (“XPS”, also known as Electron Spectroscopy for Chemical Analysis (“ESCA”)). In some embodiments, particularly preferred are guanidine-functionalized aluminum silicate particles. Suitable guanidine-functionalized aluminum silicate particles for use according to the present disclosure include those that comprise an amorphous aluminum silicate and that have a surface composition having a metal atom to silicon atom ratio greater than 6.7 and less than or equal to about 17.3, as determined by XPS (also known as ESCA). In some embodiments, particularly preferred are guanidine-functionalized perlite particles. 
     In an embodiment, the concentration agent particles comprise particles of diatomaceous earth, for instance particles of surface-modified diatomaceous earth. Diatomaceous earth (or kieselguhr) is a natural siliceous material produced from the remnants of diatoms, a class of ocean-dwelling microorganisms. Thus, it can be obtained from natural sources and is also commercially available (for example, from Alfa Aesar, A Johnson Matthey Company, Ward Hill, Mass. or Dicaperl Minerals Corporation, Crawfordsville, Ind.). Diatomaceous earth particles generally comprise small, open networks of silica in the form of symmetrical cubes, cylinders, spheres, plates, rectangular boxes, and the like. The pore structures in these particles can generally be remarkably uniform. 
     Diatomaceous earth can be used in carrying out the process of the invention as the raw, mined material or as purified and optionally milled particles. Preferably, the diatomaceous earth is in the form of milled particles with sizes in the range of about 1 micrometer to about 50 micrometers in diameter (more preferably, about 3 micrometers to about 10 micrometers). The diatomaceous earth can optionally be heat treated prior to use to remove any vestiges of organic residues. If a heat treatment is used, it can be preferable that the heat treatment be at 500° C. or lower, as higher temperatures can produce undesirably high levels of crystalline silica. 
     Surface-modified diatomaceous earth comprises diatomaceous earth bearing, on at least a portion of its surface, a surface treatment comprising titanium dioxide, ferric oxide, fine-nanoscale gold or platinum, or a combination thereof. Useful surface modifiers include fine-nanoscale gold; fine-nanoscale platinum; fine-nanoscale gold in combination with at least one metal oxide (preferably, titanium dioxide, ferric oxide, or a combination thereof); titanium dioxide; titanium dioxide in combination with at least one other (that is, other than titanium dioxide) metal oxide; and the like; and combinations thereof. Preferred surface modifiers include fine-nanoscale gold; fine-nanoscale platinum; fine-nanoscale gold in combination with at least ferric oxide or titanium dioxide; titanium dioxide; titanium dioxide in combination with at least ferric oxide; and combinations thereof. Surface-modified diatomaceous earth can be made, for example, according to methods disclosed in commonly assigned International Publication No. WO 2009/046191 (Kshirsagar et al.). 
     In an embodiment, the concentration agent particles comprise particles of gamma-FeO(OH) (also known as lepidocrocite). Specific examples of such concentration agent particles are disclosed in commonly assigned International Publication No. WO2009/046183 (Kshirsagar et al.). Gamma-FeO(OH) particles have been found to be surprisingly more effective than other iron-containing concentration agent particles in capturing gram-negative bacteria, which can be of great concern in regard to human bacterial infections. 
     Gamma-FeO(OH) is known and can be chemically synthesized by known methods (for example, by oxidation of ferrous hydroxide at neutral or slightly acidic pHs, as described for purposes of magnetic tape production in U.S. Pat. No. 4,729,846 (Matsui et al.), the description of which is incorporated herein by reference). Gamma-FeO(OH) is also commercially available (for example, from Alfa Aesar, A Johnson Matthey Company, Ward Hill, Mass., and from Sigma-Aldrich Corporation, St. Louis, Mo.). 
     In an embodiment, the concentration agent particles comprise particles of silica. A specific example of concentration agent silica particles is silicon dioxide microspheres having a mean diameter of about 2.5 microns that are commercially available from PolySciences, Inc., (Warrington, Pa.). 
     In an embodiment, the concentration agent particles comprise particles of metal carbonates. A specific example of concentration agent metal carbonate particles is calcium carbonate, such as calcium carbonate particles having a diameter range of 2.5-10 microns that are commercially available from Sigma-Aldrich, (St. Louis, Mo.). 
     In an embodiment, the concentration agent particles comprise particles of metal phosphates. A specific example of concentration agent metal phosphate particles is hydroxyapatite, such type-1 hydroxyapatite particles having particle sizes from 2-8 microns that are commercially available from Sigma-Aldrich, (St. Louis, Mo.). 
     In one specific method, the nonwoven article is prepared using a wet laying or “wetlaid” process. In this process, a dispersion is formed that contains (a) a plurality of fibers, (b) a plurality of concentration agent particles, (c) polymeric binder fibers, (d) and a dispersing liquid such as water, a water-miscible organic solvent, or a mixture thereof. The fibers and concentration agent particles can be dispersed together in the dispersing liquid. In some embodiments, the fibers (for example, hydrophobic fibers) have additives, surface treatments, or chemical groups that facilitate dispersion of the fibers in the dispersion liquid. For example, polyolefin-based fibers can have maleic anhydride or succinic anhydride functionality, or, during the melt-processing to prepare polyolefin-based fibers, a suitable surfactant can be added. 
     The wetlaid process additionally includes dewatering, followed by heating to finish the dewatering and optionally to bind some of the fibers together. 
     One or more adjuvants or additives can be used in preparing this type of nonwoven article. Useful adjuvants include process aids, materials that can enhance the overall performance of the resulting nonwoven article, and the like. When used, the amounts of such adjuvants can be present, for example, in an amount up 5 weight percent, up to 4 weight percent, up to 3 weight percent, up to 1 weight percent, or up to 0.5 weight percent based on a total dry weight of the nonwoven article (for example, fibers and concentration agent particles). The total amount of adjuvants is typically selected to be as low as possible so as to maximize the amount of concentration agent particles that can be included in the nonwoven article. 
     In one more specific wetlaid process, the fibers (for example, chopped fibers) can be blended in a container in the presence of the dispersing liquid (for example, water, a water-miscible organic solvent such as an alcohol, or a mixture thereof) to form a slurry. After formation of the slurry, the concentration agent particles and an optional precipitation agent (for example, a pH adjusting agent such as alum) can be added to the slurry. 
     When the wetlaid process is carried out by using hand-sheet methods known in the art, the order of addition of the components (i.e., fibers and concentration agent particles) to the dispersion has not been found to significantly affect the ultimate performance of the concentration device. After formation, the dispersion mixture can be poured into a mold, the bottom of which can be covered by a screen. The dispersing liquid can be allowed to drain from the mixture (in the form of a wet sheet) through the screen. After sufficient liquid has drained, the wet sheet generally can be removed from the mold and dried by pressing, heating, or a combination of the two. Generally pressures are in a range of about 300 to about 600 kPa. Temperatures in a range of 90° C. to 200° C., in a range of 100° C. to 175° C., in a range of 100° C. to 150° C., or in a range of90° C. to 120° C. can be used for drying the wet sheet. Drying often removes all or most of the dispersing liquid (for example, up to 85 weight percent, up to 90 weight percent, up to 95 weight percent, up to 98 weight percent, or up to 99 weight percent of the dispersing liquid based on the amount of dispersing liquid added to form the dispersion). 
     The resulting nonwoven article is a dry sheet having an average thickness of at least 0.1 millimeter, at least 0.2 millimeters, at least 0.5 millimeters, at least 0.8 millimeters, at least 1 millimeter, at least 2 millimeters, at least 4 millimeters, or at least 5 millimeters. The average thickness is often up to 20 millimeters, up to 15 millimeters, up to 12 millimeters, or up to 10 millimeters. Calendering can be used to provide additional pressing or fusing, if desired, of the dry sheet. 
     In the nonwoven article, the concentration agent particles can be entrapped in the fibrous porous matrix through either chemical interactions (for example, chemical bonding) or physical interactions (for example, adsorption or mechanical entrapment), depending upon the nature of the fibers that are utilized. The concentration agent particles are often preferably distributed essentially uniformly throughout the fibrous porous matrix within the nonwoven article, for instance including at each surface and throughout the depth of the fibrous porous matrix. 
     Generally the average pore size of the dry nonwoven article can be in a range of 0.1 to 10 micrometers, as measured by scanning electron microscopy (SEM). Void volumes in the range of 20 to 80 volume percent or in a range of 40 to 60 volume percent can be useful. The porosity of the dry nonwoven article can be modified (increased) by using fibers of larger diameter or stiffness in the fiber mixture. The basis weight of the nonwoven article (in the form of sheet material) can be in the range of about 100 to about 350 grams per square meter (g/m 2 ), preferably, in the range of about 200 to about 300 g/m 2 , such as about 250 g/m 2 . 
     In certain embodiments, contacting comprises passing the fluid sample through the nonwoven article using a sample delivery system. One suitable sample delivery system comprises a freestanding container comprising a first reservoir and a deformable self-supporting receptacle dimensioned to be received in the first reservoir of the freestanding container and comprising a second reservoir. The freestanding container is more rigid than the deformable self-supporting receptacle, and the freestanding container includes a base comprising an aperture formed therein, through which the deformable self-supporting receptacle can be accessed. Accordingly, fluid sample is passed through the nonwoven article by applying external pressure to the deformable self-supporting receptacle via the aperture in the freestanding container to pass the fluid sample through the nonwoven article. The sample delivery system is discussed in detail below. 
     In a second aspect, a device for contacting a fluid sample with a nonwoven article is provided. The device includes a sample container, a filter holder, a nonwoven article, and a first adaptor configured to interface the filter holder with a receptacle. Referring to  FIG. 7A , a perspective schematic of an exemplary filter holder  14  is shown. The filter holder  14  is configured to interface with a sample delivery system. Referring to  FIG. 7B , a first adaptor  18  is configured to interface the filter holder  14  with a receptacle (not shown). In certain embodiments, the first adaptor  18  comprises a hollow shape (e.g., a hollow cylinder) having a ledge  19  on which the nonwoven article  16  is placed. Referring to  FIG. 7C , a perspective schematic of the filter holder  14  is shown, including a first adaptor  18  disposed inside the filter holder  14  and a nonwoven article  16  disposed on the ledge  19  of the first adaptor  18 . Referring to  FIG. 7D , a perspective schematic of an exemplary sample preparation system  100  is shown. The sample preparation system  100  includes a container  102 , a liner  104 , a lid  106 , and a collar  108 . The lid  106  comprises a port  132  extending from the center of the lid  106 . The sample preparation system is described in detail below with respect to  FIG. 6 . Referring now to  FIG. 7E , a side view schematic of an exemplary device  10  is shown, including the sample preparation system  100  of  FIG. 7D . The device  10  further comprises the filter holder  14 , nonwoven article  16 , and first adaptor  18  of  FIG. 7C  disposed on the port  132  of the lid  106 . In this embodiment, the lid  106  further comprises a plurality of protrusions  116  that cooperate with the filter holder  14  to fix the filter holder  14  in place on the lid  106 . 
     It is not necessary for the filter holder to be a separate piece, but rather it could be integral to the lid. For instance, the filter holder and lid could be molded as one piece with no need for a port. In such a case the filter holder could have a cap to prevent contamination that would need to be removed before filtration. The lid could then be removed and the nonwoven article could be pushed from the top of the lid, crumpling the nonwoven article during its removal. 
     In a third aspect, another device for contacting a fluid sample with a nonwoven article is provided. The device includes a sample container, a filter holder configured to interface with a receptacle, and a nonwoven article. The nonwoven article for each of the second and third aspects includes a fibrous porous matrix and a plurality of concentration agent particles enmeshed in the fibrous porous matrix. Typically, the filter holder comprises an exterior ledge that is configured to interface with the receptacle. In certain embodiments, the filter holder comprises an interior ledge configured to hold the nonwoven article. 
     Referring to  FIGS. 1A-1E , an exemplary device  10  according to the disclosure, for contacting a fluid sample with a nonwoven article is illustrated. The device  10  comprises a sample container  12 ; a filter holder  14 ; and a nonwoven article  16  comprising a fibrous porous matrix  15  and a plurality of concentration agent particles  17  enmeshed in the fibrous porous matrix  15 .  FIG. 1D  shows a bottom plan schematic of the filter holder  14 , in which an exterior ledge  11  is illustrated. The exterior ledge  11  of the filter holder  14  is configured to interface with a receptacle (not shown). The filter holder  14  further comprises an interior ledge  13  configured to hold the nonwoven article  16 .  FIG. 1B  provides a cross-sectional schematic view of the filter holder  14  comprising the nonwoven article  16  disposed adjacent to the interior ledge  13 . Hence, the sample container  12  can be unattached from the filter holder  14  and the nonwoven article  16  readily removed from inside the filter holder  14 , such as pushed into a receptacle. Having the filter holder  14  configured to interface with a receptacle, such as the exterior ledge  11 , simplifies transferring the nonwoven article  16  from the filter holder  14  to a receptacle.  FIG. 1E  shows the assembled device, including the sample container  12  attached to the filter holder  14  (i.e., threaded onto the filter holder) and the nonwoven article  16  is disposed in the filter holder  14 . One of skill in the art will appreciate that other methods of attachment (e.g., press-fit engagement, snap-fit engagement, clamping engagement, etc.) may be employed to assemble and disassemble two or more components of the device. 
     As discussed above, it is not necessary for the filter holder to be a separate piece, but rather it could be integral to the sample container. The sample container could then be removed and the nonwoven article could be pushed from the inside of the sample container, crumpling the nonwoven article during its removal. 
     Referring to  FIGS. 2A-2E , another exemplary device  10  according to the disclosure, for contacting a fluid sample with a nonwoven article is illustrated. The device  10  comprises a sample container  12 ; a filter holder  14  configured to interface with a receptacle (not shown); a nonwoven article  16  comprising a fibrous porous matrix  15  and a plurality of concentration agent particles  17  enmeshed in the fibrous porous matrix  15 ; and a second adaptor  22 . The filter holder  14  is configured as described above with respect to  FIGS. 1A -lE.  FIG. 2B  shows the second adaptor  22 . In certain embodiments, the second adaptor  22  is configured to couple the device to a source of vacuum.  FIG. 2C  illustrates the filter holder  14  attached to the second adaptor  22  (i.e., threaded onto the adaptor).  FIG. 2D  shows a side view schematic of the container  12  attached to the filter holder  14 , which is in turn attached to the second adaptor  22 . (The nonwoven article disposed inside the filter holder  14  is not shown.) Referring to  FIG. 2E , the second adaptor  22  is inserted into a stopper  23  configured to attach the device  10  to a vacuum flask (not shown). 
     Referring to  FIGS. 3A-3E , a further exemplary device  10  according to the disclosure, for contacting a fluid sample with a nonwoven article is illustrated. The device  10  comprises a sample container  12 ; a filter holder  14  configured to interface with a receptacle (not shown); a nonwoven article  16  comprising a fibrous porous matrix  15  and a plurality of concentration agent particles  17  enmeshed in the fibrous porous matrix  15 ; and a second adaptor  22 . The filter holder  14  is configured as described above with respect to  FIGS. 1A-1E .  FIG. 3B  shows the second adaptor  22 . In certain embodiments, the second adaptor  22  is configured to couple the device to a source of vacuum through a side arm.  FIG. 3C  illustrates the filter holder  14  attached to the second adaptor  22  (i.e., threaded onto the adaptor).  FIG. 3D  shows a side view schematic of the container  12  attached to the filter holder  14 , which is in turn attached to the second adaptor  22 . (The first nonwoven article disposed inside the filter holder  14  is not shown.) Referring to  FIG. 3E , the second adaptor  22  is attaches the device  10  to a fluid sample collection container  21 . Hence, in an embodiment, a fluid sample is contacted with the nonwoven article by putting the fluid sample in the sample container, pulling a vacuum through the second adaptor, and collecting fluid sample that has passed through the nonwoven article in a collection container. 
     Referring to  FIG. 4A , a side view schematic of the device  10  of  FIG. 3D  is shown, further comprising a rotary pump  24 . In this embodiment, the rotary pump  24  is attached to the second adaptor  22 ; however, in alternate embodiments a rotary pump may instead be attached to the filter holder  14 . Referring to  FIG. 4B , a top view schematic of the device of  FIG. 4A  is shown, further comprising a power drill  25  attached to the rotary pump  24 . The power drill  25  is one example of a convenient tool that may be employed to create a vacuum, particularly when using the device in the field and a typical laboratory sink vacuum flask is unavailable. 
     Referring to  FIG. 5 , a side view schematic of yet another device  10  according to the disclosure, for contacting a fluid sample with a nonwoven article is illustrated. The device  10  comprises a sample container  12 ; a filter holder  14  configured to interface with a receptacle (not shown); a nonwoven article (not shown); a second adaptor  22 ; and a syringe  28 . The filter holder  14  is disposed between the syringe  28  and the sample container  12 , and connected via a tube  29 . In this embodiment, the filter holder  14  is attached to the syringe  28  by the second adaptor  22 . Including the syringe  28  provides a convenient way to swiftly contact a fluid sample with a nonwoven article, by simply pulling the plunger  27  of the syringe  28  and forcing the fluid sample through the nonwoven article with negative pressure. Alternatively, the syringe  28  could be directly connected to the filter holder  14  without using the second adaptor  22 . 
     The sample container  12  can be formed of a variety of materials including, but not limited to, polymeric materials, metals, ceramics, glasses, and combinations thereof. Examples of suitable polymeric materials include for instance and without limitation, polyolefins (e.g., polyethylene, polypropylene, combinations thereof, etc.), polycarbonate, acrylics, polystyrene, high density polyethylene (HDPE), polypropylene, other suitable polymeric materials capable of forming a freestanding and/or self-supporting container, or a combination thereof. The container  12  can be translucent (or even transparent), or opaque, and can be any suitable size, depending on the type, amount and size of source to be analyzed. For example, in some embodiments, the container  12  can have a capacity of up to 50 mL, 100 mL, 250 mL, 300 mL, 500 mL, 750 mL, or even up to 1 L. 
     Nonlimiting examples of suitable receptacles, for instance receptacles containing at least one reagent, include the 3M CLEAN-TRACE Surface ATP Swab available from 3M Company (St. Paul, Minn.), the AQUASNAP ATP Water Test available from Hygiena (Camarillo, Calif.), the ACCUPOINT 2 ATP Sanitation Monitoring System available from Neogen Corporation (Lansing, Mich.), and the PRO-CLEAN Rapid Protein Residue Test available from Hygiena. 
     In an alternate embodiment, a device is provided in which the sample container comprises a syringe. Using a syringe as a sample container allows for a convenient way to swiftly contact a fluid sample with a nonwoven article, by simply pressing the plunger of the syringe and forcing the fluid sample through the nonwoven article with positive pressure. 
     In any embodiment of the device, a gasket is disposed on or under the nonwoven article to minimize the ability of a volume of fluid sample to pass around the nonwoven article instead of through the nonwoven article. Suitable gaskets include, for instance, rubber gaskets sized to fit the perimeter of the nonwoven article, such as made from high-temperature resilient silicone foam, such as 1/16 th  inch or ⅛ th  inch thick foam commercially available from McMaster-Carr (Elmhurst, Ill.) (e.g., part number 1059N366). 
     Advantageously, a relatively large volume of fluid sample is optionally passed through the nonwoven article to concentrate the target microorganism and/or target cellular analyte, the container comprising a volume of at least 50 milliliters, or at least 100 milliliters, or at least 150 milliliters, or at least 300 milliliters, or at least 500 milliliters, or up to 1 liter. 
       FIG. 6  illustrates a sample delivery system  100  according to one embodiment of the present disclosure. As shown in  FIG. 6 , the sample delivery system  100  includes a container  102 , a liner  104 , a lid  106 , a collar  108 , and a cover  109 . In some embodiments, one or more of the components of the sample delivery system  100  are sterile or sterilizable by sterilization and disinfection procedures such as steam, gamma radiation, ethylene oxide, hydrogen peroxide, peracetic acid, hydro-alcoholic solutions, bleach, and combinations thereof. A system having similar features to that of the sample delivery system  100  is described in PCT Publication No. WO 98/32539, U.S. Pat. Nos. 6,536,687 and 6,588,681, PCT Publication No. 2004/060574, PCT Publication No. 2004/060575, US Publication No. 2004/0164182, PCT Publication No. 2004/094072, PCT Publication No. WO 2007/079143, PCT Publication No. WO 2007/079188, and PCT Publication No. WO2009/067498. 
     The container  102  is freestanding and/or self-supporting and includes a base  127  and a sidewall  129 . The term “freestanding” is generally used to refer to an object that is capable of standing on its own without collapsing or distorting, and without being held by another object. The term “self-supporting” is generally used to refer to an object that does not collapse or deform under its own weight. For example, a bag is typically not “self-supporting” in that it does not maintain its shape, but rather collapses or distorts, under its own weight. A self-supporting object is not necessarily freestanding. 
     The container  102  can be formed of the same materials as the sample container described above, and be of any of the same sizes. 
     In some embodiments, as shown in  FIG. 6 , the sample delivery system  100  includes a liner  104 , which is shaped and dimensioned to be received within the container  102 . The liner  104  can be disposable (e.g., made for one-time use), to allow the container  102  to be reused without substantial risk of contamination and without extensive cleaning required between uses. 
     As shown in  FIG. 6 , the container  102  defines a first reservoir  120 , and the liner  104  defines a second reservoir  122 . The liner  104  is shaped and dimensioned to be received within the first reservoir  120  of the container  102 . In some embodiments, a fluid sample  114  can be added to the first reservoir  120 , the fluid sample  114  comprising a sample matrix  113  and at least one microorganism strain and/or cellular analyte  112 . In some embodiments, as shown in  FIG. 6 , the fluid sample  114  is positioned within the second reservoir  122  and the liner  104  is positioned within the first reservoir  120 . In some embodiments, the liner  104  is freestanding and/or self-supporting, either of which can allow fluid sample  114  to be loaded into the liner  104  prior to positioning the liner  104  within the container  102 , without the liner  104  collapsing or distorting. 
     In certain embodiments, the liner  104  is self-supporting and/or freestanding while also being deformable. The term “deformable” is used to refer to a structure that can be altered from its original shape or state by pressure (e.g., positive or negative) or stress. In embodiments employing a deformable liner  104 , pressure can be applied to the liner  104  to reduce its size from its original (i.e., unstressed) dimensions. Such pressure can be used to promote removal of the fluid sample  114  (or a filtrate thereof) from the liner  104 . In such embodiments, the liner  104  can serve as a deformable self-supporting receptacle that can contain the fluid sample  114 . In some embodiments, the deformable self-supporting receptacle is also freestanding. 
     In the embodiment shown in  FIG. 6 , the container  102  includes an aperture  124  formed in its base  127 , through which a user can access the liner  104  to apply pressure to the liner  104  to cause it to deform. Such pressure can be applied directly by hand, or by an additional device, and could be a manual or automated process. 
     In some embodiments, the liner  104  includes a relatively rigid base  126  and a relatively thin and deformable sidewall  128 , such that when pressure is applied to the base  126  in a direction parallel to the longitudinal axis of the liner  104  (e.g., via the aperture  124  in the container  102 ), the liner  104  deforms in the longitudinal direction (e.g., by virtue of the sidewall  128  collapsing rather than the base  126 ). Alternatively, or in addition, the base  126  can be thicker than the sidewall  128 . 
     In certain embodiments, the lid  106  is removably coupled to the liner  104 , and the collar  108  is employed to further secure the lid  106  to the container  102 . For example, in  FIG. 6 , the container  102  includes threads  131  at the upper end of the outer surface of the sidewall  129 , which are shaped and dimensioned for the collar  108  (having internal threads  133  capable of engaging with the threads  131  on the container  102 ) to be screwed onto the upper end of the container  102 . 
     As an alternative to using the collar  108  for securing the lid  106  to the container  102 , other coupling means can be employed including clamping and/or any of the other coupling means. A variety of coupling means can be employed either between the lid  106  and the liner  104 , the lid  106  and the container  102 , and/or the collar  108  and the container  102  to allow the respective components to be removably coupled to one another, including, but not limited to, gravity (e.g., one component can be set atop another component, or a mating portion thereof), screw threads, press-fit engagement, snap-fit engagement, magnets, adhesives, heat sealing, other suitable removable coupling means, and combinations thereof. 
     In some embodiments, the sample delivery system  100  need not be reopened after the fluid sample  114  is added, such that the container  102 , the liner  104 , the lid  106  and the collar  108  need not be removably coupled to one another, but rather can be permanently or semi-permanently coupled to one another. 
     As shown in  FIG. 6 , the lid  106  further includes a port  132 , which can be coupled to a filter  134 , a cylindrical portion  136  that is dimensioned to be received within the liner  104 , and a generally conical (e.g., frusto-conical) portion  138  that extends from the cylindrical portion  136  to the port  132 . At the junction between the cylindrical portion  136  and the conical portion  138 , the lid  106  further includes a lip  140  that extends radially outwardly from the cylindrical portion  136  and the conical portion  138 . 
     In some embodiments, the filter  134  is coupled directly to the lid  106 . In some embodiments, as shown in  FIG. 6 , the filter  134  can be supported by a frame  135  and coupled to the lid  106  via the frame  135 . The frame  135  can form a portion of the filter  134 , the frame  135  can be a part of the lid  106 , or the frame  135  can be a separate element that is coupled to both the filter  134  and the lid  106 . The frame  135  can be formed of a variety of materials, including, but not limited to, a variety of polymers, metals, ceramics, glasses, and combinations thereof. 
     As shown in  FIG. 6 , the collar  108  includes an inwardly-projecting lip  156 , such that when the collar  108  is coupled to the container  102 , the lip  156  of the collar  108  presses the lip  140  of the lid  106  into contact with the lip  146  of the liner  104 , which is pressed into contact with the upper surface  146  of the container  102  (e.g., to form a higher integrity seal). The above-described means for assembling the sample delivery system  100  and for forming a seal between the components of the sample delivery system  100  are described and illustrated by way of example only. One of ordinary skill in the art will understand, however, that a variety of other mechanisms could be employed to assemble the components of the sample delivery system  100  and to form a seal (e.g., a liquid-tight seal, a hermetic seal, or a combination thereof), such that the sample delivery system  100  is inhibited from leaking under normal operating conditions. 
     The lid  106  can be formed of a variety of materials, including the materials listed above with respect to the sample container  12 . The lid  106  can be translucent (or even transparent), or opaque, depending on the application of use. 
     The collar  108  can be formed of a variety of materials, including, but not limited to a variety of polymeric materials, metal materials, and combinations thereof. For example, the collar  108  can be formed of a molded plastic component, or a machined metal (such as aluminum) component. In some embodiments, the collar  108  is formed of a molded plastic component comprising glass fiber reinforced polypropylene. 
     As shown in  FIG. 6 , the port  132  of the lid  106  is generally cylindrical and tubular in shape, such that the port  132  defines a portion  152  of an inner surface of the lid  106  and an opening  154  in the lid  106 . The lid  106  is hollow and is in fluid communication with the second reservoir  122  when the sample delivery system  100  is assembled. The port  132  does not need to be cylindrical and can instead take on any shape necessary for a given application. In the embodiment illustrated in  FIG. 6 , the filter  134  is coupled to the port  132  (i.e., via the frame  135 ) such that the filter  134  is in fluid communication with the lid opening  154 , as well as the second reservoir  122 . 
     In the embodiment shown in  FIG. 6 , the cover  109  is shaped and dimensioned to receive at least a portion of the port  132 . As a result, the cover  109  can be coupled to the port  132  of the lid  106  to close the opening  154  in the lid  106  and to seal (e.g., hermetically seal) the sample delivery system  100  from the environment. The cover  109  can be coupled to the lid  106  using any suitable coupling means. The cover  109  can be integrally formed with the lid  106  (e.g., a flip-top snap-on cover), or the cover  109  can be separate from the lid  106  (e.g., a screw-on cover). The cover  109  can be formed of a variety of materials, including the materials listed above with respect to the container  102  or the collar  108 . 
     The filter  134  can be of any geometrical shape to sufficiently filter the fluid sample  114 . In some embodiments, the filter  134  is deformable and/or collapsible (i.e., such that the filter  134  folds under its own weight). In some embodiments, the filter  134  is rigid and retains its shape (i.e., does not fold under its own weight). The size and number of filters  134  used in a sample delivery system  100 , and porosity thereof, may vary, depending on the desired analyte(s) and the insoluble matter in the sample matrix  113 . 
     By way of example only, in some embodiments, the fluid sample  114  comprises a lysed bacterial cell culture, the desired analyte is one or more of DNA, RNA, a protein, ATP, or a metabolite, and the insoluble matter is cellular debris. In such embodiments, for example, the filter  134  can be selected or treated (e.g., derivatized with biomolecule-binding agents, such as antibodies) to retain and/or separate the cellular debris, while allowing the desired DNA, RNA, protein, ATP, and/or metabolite to pass through the filter  134  for subsequent capture by the nonwoven article. 
     The filter  134  can have a variety of pore sizes sufficient for retaining particles from the fluid sample  114 , while allowing the desired analyte(s) (if present) in the fluid sample  114  to pass through the filter  134 . In some embodiments, the filter  134  has an average pore or mesh size of at least 2 micrometers, in some embodiments, at least 5 micrometers, in some embodiments, at least 40 micrometers, in some embodiments, at least 80 micrometers, and in some embodiments, at least 120 micrometers. In some embodiments, the filter  134  has an average pore or mesh size of at most 2000 micrometers, in some embodiments, at most 1000 micrometers, in some embodiments, at most 500 micrometers, in some embodiments, at most 200 micrometers, in some embodiments, at most 50 micrometers, in some embodiments, at most 10 micrometers and in some embodiments, at most 1 micrometers (e.g., if it is desired to restrict bacteria from passing through the filter  134 ). Optionally, the filter  134  acts as a coarse filter. 
     The filter  134  can be formed from a variety of materials, including, but not limited to one or more of nylon, fluorinated polymers (e.g., polytetrafluoroethylene (PTFE)), cellulosics (e.g., modified celluloses such as cellulose esters (e.g., cellulose acetate) and nitrocelluloses), fiberglass, papers, and combinations thereof. In some embodiments, the filter  134  can be formed of a woven web, a nonwoven web, a molded structure, a foam, fabric, a fibrous web, and combinations thereof. The surface area of the filter  134  can be increased by pleating the filter  134 , or by other similar techniques. The thickness of the filter  134  can be controlled by calendering or felting processes. 
     Following contact of a fluid sample with the nonwoven article, the device according to the disclosure is optionally at least partially disassembled and the first adaptor or the filter holder is interfaced with a receptacle. When interfaced with the receptacle, the nonwoven article is readily transferred from the device and placed in contact with at least one detection reagent. In certain embodiments, the nonwoven article can be moved using forceps, while in other embodiments the nonwoven article can be pushed through the hollow interior and/or off of the ledge of the first adaptor or filter holder, and into contact with one or more detection reagents. 
     Referring to  FIGS. 8A-8E , an exemplary method of detecting at least one bound microorganism strain or at least one bound cellular analyte is shown.  FIG. 8A  shows a filter holder  14  containing a first adaptor  18  and a nonwoven article  16  disposed on the first adaptor  18 . A handle  32  of a detection device (not shown) is inserted into the first adaptor  18 .  FIG. 8B  shows the handle  32  being removed from the filter holder  14 , in which the first adaptor  18  and the nonwoven article  16  are also removed from the filter holder on an end  33  of the handle  32  of a detection device.  FIG. 8C  shows the end  33  of the handle  32  of a detection device  30  being inserted into the detection device  30 . The first adaptor  18  fits inside a top opening of the detection device  30 .  FIG. 8D  shows the handle  32  pushed down into the detection device  30 . Due to the hollow configuration of the first adaptor  18 , the end  33  of the handle  32  of the detection device  30  pushes the nonwoven article  16  down towards a lower end of the detection device  30  as the handle  32  is fully inserted into the detection device  30 . In this embodiment, the detection device  30  comprises at least one reagent disposed in the lower end of the detection device  30 . Microorganism strain(s) and target cellular analyte(s) bound to the nonwoven article  16  have an opportunity to react with the one or more reagents and generate a detectable signal. Referring to  FIG. 8E , the detection device  30  is operationally coupled to a luminometer  50 , which allows a generated luminescent signal to be detected. 
     The above-described means for transferring the non-woven article with bound microorganisms and/or cellular analytes is described and illustrated by way of example only. One of ordinary skill in the art will understand, however, that a variety of other mechanisms could be employed to transfer the non-woven article to a variety of detection devices depending on the configuration of the detection devices. In certain embodiments, for instance, a filter holder can be set on a detection device and the nonwoven article pushed through the filter holder into the detection device. 
     Referring to  FIGS. 9A-9F , another exemplary device is illustrated. More particularly,  FIG. 9A  shows a syringe adaptor  92 . The syringe adaptor may also be referred to as a second adaptor, for instance in a device for contacting a fluid sample with a nonwoven article including 1) a sample container, 2) a filter holder, 3) a nonwoven article, 4) a first adaptor configured to interface the filter holder with a receptacle, and 5) a second adaptor configured to attach the filter holder to the sample container. In the embodiment illustrated, the syringe (e.g., second) adaptor  92  advantageously includes a luer lock connector  95  for quick attachment and removal of a syringe from the rest of the device. The syringe adaptor  92  further includes a threaded portion  96  disposed on an exterior surface of the syringe adaptor  92 , which imparts some flexibility to the exterior surface of the syringe adaptor  92  to assist in inserting at least some of the threaded portion  96  of the syringe adaptor  92  into the filter holder  94  of  FIG. 9D  (and being able to separate the syringe adaptor  92  from the filter holder  94  after use). Optionally, the filter holder  94  may have a complementary threaded portion located on an interior surface  91  so that the syringe adaptor  92  and the filter holder  94  could be specifically threaded together. Alternatively, other conventional methods of attaching two parts together may be employed, such as a twist and lock system, or compression fit parts, or the like. In addition, the syringe adaptor  92  includes at least one wing  97  (such as the two wings  97  shown in  FIG. 9A ) which can optionally provide the dual functions of assisting in handling of the syringe adaptor  92  by a user and securing a ledge  98  on the filter holder  94 . The wing  97  preferably includes a tab  101  configured to secure the ledge  98  of the filter holder  94 . A different schematic perspective view of the syringe adaptor  92  is provided in  FIG. 9B . 
     Referring to  FIG. 9C , a filter holder  94  is illustrated. The filter holder  94  includes a first adaptor  18  disposed in the filter holder  94 .  FIG. 9D  is a schematic perspective view of a filter holder  94  containing a nonwoven article  16  secured to a first adaptor  18  with a gasket  93  (e.g., an O-ring). 
       FIG. 9E  is a schematic perspective view of the syringe adaptor  92  of  FIG. 9B  coupled to the filter holder  94  of  FIG. 9D . Optionally, a luer lock connector (not shown) may also be provided at the aperture  99  present in the end of the filter holder  94  opposite the ledge  98 , to attach a syringe and apply a vacuum to pull sample through the nonwoven article. Similarly, other sources of vacuum could be attached to the aperture  99 , such as a pump or vacuum flask, and might be suitable for use to ensure all of a sample is passed through a nonwoven article in the device  90 . 
       FIG. 9F  is a schematic side view of a device  90  including a syringe  28 , the syringe adaptor  92  of  FIG. 9A , and the filter holder  94  of  FIG. 9D . In operation, a fluid sample is introduced into the syringe  28 , then the syringe is attached to the rest of the device  90  using the luer lock connector  95  of the syringe adaptor  92 . To capture microorganisms from the fluid sample, the plunger  27  of the syringe  28  is pressed, pushing the fluid sample to pass through the syringe adaptor  92  and the nonwoven article  16 . The filter holder  94  may then be separated from the syringe adaptor  92  to provide access to the nonwoven article  16  for detection of bound microorganisms and/or cellular analytes. 
     Optionally, similar to the method demonstrated in  FIGS. 8A-8E , the handle of a detection device may be inserted into the first adaptor  18 . When the handle is subsequently removed from the filter holder  94 , the first adaptor  18  and the nonwoven article  16  are also removed from the filter holder  94  on an end of the handle of a detection device. Next, the end of the handle of a detection device may be inserted into the detection device, in which the first adaptor  18  fits inside a top opening of the detection device. The handle is then pushed down into the detection device, and due to the hollow configuration of the first adaptor  18 , the end of the handle of the detection device pushes the nonwoven article  16  down towards a lower end of the detection device as the handle is fully inserted into the detection device. Microorganism strain(s) and target cellular analyte(s) bound to the nonwoven article  16  thus have an opportunity to react with the one or more reagents and generate a detectable signal. 
     Referring to  FIGS. 10A-10H , another exemplary device is illustrated, including 1) a sample container, 2) a filter holder, 3) a nonwoven article, and 4) a first adaptor configured to interface the filter holder with a receptacle. The filter holder  14   a - 14   b  includes two separable parts; a first filter holder portion  14   a  and a second filter holder portion  14   b .  FIG. 10A  shows the first filter holder portion  14   a . In the embodiment illustrated, the first filter holder portion  14   a  advantageously includes a luer lock connector  95  for quick attachment and removal of a container such as a syringe  28  from the rest of the device. As shown in  FIG. 10B , the first filter holder portion  14   a  further includes an interior ledge  13  and a threaded portion  96  disposed on an interior surface of the first filter holder portion  14   a , which allows connection of the first filter holder portion  14   a  with the second filter holder portion  14   b  of  FIG. 10F  (and allows separation of the first and second filter holder portions  14   a  and  14   b  from each other after use). Accordingly, the second filter holder portion  14   b  has a complementary threaded portion  96  located on an exterior surface of the second filter holder portion  14   b . Alternatively, other conventional methods of attaching two parts together may be employed, such as a twist and lock system, or compression fit parts, or the like. 
     Referring to  FIG. 10C , a first adaptor  18  is shown. In the illustrated embodiment, the first adaptor  18  is shaped to have a flat major surface  155  and an angled major surface  157  opposite the flat major surface  155 , and to define an aperture that extends between the flat major surface  155  and the angled major surface  157 . The first adaptor  18  is configured to be disposed in the first filter holder portion  14   a  (on the interior ledge  13 ), as shown in  FIG. 10D , with the flat major surface  155  in contact with the interior ledge  13 .  FIG. 10E  is a schematic perspective view of a first filter holder portion  14   a  containing the first adaptor  18 , a nonwoven article  16  disposed on the first adaptor  18 , and a gasket  93  disposed on the nonwoven article  16 . The gasket  93  is generally composed of a resilient material to assist in preventing a fluid from going around the edge of the nonwoven article  16  but instead through the nonwoven article  16 . Depending on the dimensions of the interior of the first filter holder portion  14   a  and the second filter holder portion  14   b , the first adaptor  18  may have the form of a short tube (similar to the tube shape of the first adaptor  18  shown in  FIG. 7B ). 
     As noted above,  FIG. 10F  shows the second filter holder portion  14   b . In the illustrated embodiment, the second filter holder portion  14   b  includes a fluid-permeable support  160  (which assists in securing the nonwoven article  16  in place in the filter holder  14   a - 14   b ), a threaded portion  96 , and an outlet  158  that allows fluid to pass out of the filter holder  14   a - 14   b . In alternate embodiments, no support  160  is provided; rather, the gasket  93  and first adaptor  18  cooperate to provide sufficient support to the nonwoven article  16 . Optionally, a luer lock connector (not shown) may also be provided at the outlet  158  present at the end of the second filter holder portion  14   b , to attach a syringe and apply a vacuum to pull sample through the nonwoven article  16 . Similarly, other sources of vacuum could be attached to the outlet  158 , such as a pump or vacuum flask, and might be suitable for use to ensure all of a sample is passed through a nonwoven article in the device  200 . 
     Referring now to  FIG. 10G , an exploded side view of the device  200  is provided. The device  200  includes the syringe  28  (e.g., the sample container), the first filter holder portion  14   a , the first adaptor  18 , the nonwoven article  16 , the gasket  93 , and the second filter holder portion  14   b . Similarly,  FIG. 10H  provides a side view of the assembled device  200 , including 1) a sample container (i.e., the syringe  28 ), 2) a filter holder (comprising a first filter holder portion  14   a  and a second filter holder portion  14   b ), 3) a nonwoven article  16 , 4) a gasket  93 , and 5) a first adaptor  18  configured to interface the filter holder  14   a - 14   b  with a receptacle. The filter holder  14   a - 14   b  contains the first adaptor  18  and the nonwoven article  16 . 
     In operation, a fluid sample is introduced into the syringe  28 , then the syringe is attached to the rest of the device  200  using the luer lock connector  95  of the filter holder  14   a - 14   b . To capture microorganisms from the fluid sample, the plunger  27  of the syringe  28  is pressed, pushing the fluid sample to pass through the first filter holder portion  14   a , the first adaptor  18 , the nonwoven article  16 , and the second filter holder portion  14   b . The filter holder  14   a - 14   b  may then be separated into its first and second filter holder portions  14   a  and  14   b  to provide access to the nonwoven article  16  for detection of bound microorganisms and/or cellular analytes. 
     Referring now to  FIGS. 11A-11C , similar to the method demonstrated in  FIGS. 8A-8E , the handle  32  of a detection device  30  may be inserted into the first adaptor  18 . When the handle  32  is subsequently removed from the first filter holder portion  14   a , the first adaptor  18  and the nonwoven article  16  are also removed from the first filter holder portion  14   a  on an end  33  of the handle  32  of a detection device  30 . Next, the end  33  of the handle  32  of the detection device  30  may be inserted into the detection device  30 , in which the first adaptor  18  fits inside a top opening of the detection device  30 . The handle  32  is then pushed down into the detection device  30 , and due to the hollow configuration of the first adaptor  18 , the end  33  of the handle  32  of the detection device  30  pushes the nonwoven article  16  down towards a lower end of the detection device  30  as the handle  32  is fully inserted into the detection device  30 . Microorganism strain(s) and target cellular analyte(s) bound to the nonwoven article  16  thus have an opportunity to react with the one or more reagents and generate a detectable signal. 
     In a fourth aspect, a kit is provided. The kit includes a device for contacting a fluid sample with a nonwoven article, and a receptacle. The device includes a sample container, a filter holder, a nonwoven article, and a first adaptor. The first adaptor is configured to interface the filter holder with the receptacle. The nonwoven article includes a fibrous porous matrix and a plurality of concentration agent particles enmeshed in the fibrous porous matrix. 
     Often, a second adaptor is provided and configured to attach the filter holder to a vacuum source or to a collection container. In certain embodiments, the device further includes a rotary pump attached to the filter holder or to the second adaptor. The second adaptor and rotary pump are as described above with respect to the first aspect. In many embodiments of the kit, the receptacle contains at least one reagent, although in alternate embodiments, one or more reagents can be added to the receptacle at the time of use of the kit. Typically, the receptacle is configured to be operationally connected to a detection instrument, such as a luminometer. 
     In many embodiments, the kit further includes instructions for using the kit. Such instructions typically include method details in accordance with the first aspect above. 
     Various embodiments are provided that include a method, a device, and a kit. 
     Embodiment 1 is a method of detecting microorganisms in a fluid sample. The method includes a) providing a nonwoven article, b) providing a fluid sample suspected of containing at least one microorganism strain or target cellular analyte, and c) contacting the fluid sample with the nonwoven article such that at least a portion of the at least one microorganism strain or target cellular analyte is bound to the nonwoven article. The nonwoven article includes 1) a fibrous porous matrix and 2) a plurality of concentration agent particles enmeshed in the fibrous porous matrix. The method further includes d) placing the at least one microorganism strain- or target cellular analyte-bound nonwoven article in contact with at least one detection reagent, and e) detecting the presence of the at least one bound microorganism strain or bound target cellular analyte. 
     Embodiment 2 is the method of embodiment 1, wherein the detecting includes a culture-based detection method, an imaging detection method, a fluorescence-based detection method, a colorimetric detection method, an immunological detection method, a genetic detection method, a bioluminescence-based detection method, or a combination thereof. 
     Embodiment 3 is the method of embodiment 1, wherein the detecting includes a bioluminescence-based detection method. 
     Embodiment 4 is the method of embodiment 1 or embodiment 2, wherein the reagent includes luciferase. 
     Embodiment 5 is the method of embodiment 4, wherein the reagent further includes luciferin. 
     Embodiment 6 is the method of embodiment 4, wherein the reagent further includes a lysis agent. 
     Embodiment 7 is the method of any of embodiments 1 to 6, wherein the contacting includes filtration of the fluid sample through the nonwoven article. 
     Embodiment 8 is the method of any of embodiments 1 to 7, further including passing the fluid sample through a coarse filter prior to the contacting the fluid sample with the nonwoven article. 
     Embodiment 9 is the method of any of embodiments 1 to 8, further including washing the at least one microorganism strain- or target cellular analyte-bound nonwoven article prior to the placing the at least one microorganism strain- or target cellular analyte-bound nonwoven article in contact with at least one detection reagent. 
     Embodiment 10 is the method of any of embodiments 1 to 9, wherein the placing includes placing the at least one microorganism strain- or target cellular analyte-bound nonwoven article in a receptacle including a material through which a detection signal can be detected. The receptacle contains the at least one reagent. 
     Embodiment 11 is the method of any of embodiments 1 to 10, wherein the placing includes placing the at least one microorganism strain- or target cellular analyte-bound nonwoven article in a receptacle configured to be operationally coupled to a luminometer. The receptacle contains the at least one reagent. 
     Embodiment 12 is the method of any of embodiments 1 to 11, wherein the contacting includes pushing the at least one microorganism strain- or target cellular analyte-bound nonwoven article into a receptacle containing the at least one reagent. 
     Embodiment 13 is the method of any of embodiments 1 to 12, wherein the target cellular analyte includes at least one nucleic acid, protein, or adenosine triphosphate (ATP). 
     Embodiment 14 is the method of any of embodiments 1 to 13, wherein the contacting includes passing the fluid sample at least twice through the nonwoven article. 
     Embodiment 15 is the method of any of embodiments 1 to 14, wherein the contacting includes passing the fluid sample through the nonwoven article at a pressure of 14.7 pounds per square inch (psi) (101.3 kilopascals (kPa)) or less. 
     Embodiment 16 is the method of any of embodiments 1 to 15, wherein the contacting includes passing the fluid sample through the nonwoven article at a pressure of 4.0 psi (27.6 kPa) or less. 
     Embodiment 17 is the method of any of embodiments 1 to 16, wherein the contacting includes passing the fluid sample through the nonwoven article at a pressure of 0.5 psi (3.4 kPa) or less. 
     Embodiment 18 is the method of any of embodiments 1 to 17, wherein the microorganism strain is selected from strains of bacteria, fungi, protozoans, viruses, bacterial endospores, and combinations thereof. 
     Embodiment 19 is the method of any of embodiments 1 to 18, wherein the target cellular analyte includes ATP. 
     Embodiment 20 is the method of any of embodiments 1 to 19, wherein the fibrous porous matrix is a nonwoven fibrous layer and the concentration agent particles are distributed throughout the nonwoven fibrous layer. 
     Embodiment 21 is the method of any of embodiments 1 to 20, wherein the concentration agent particles include amorphous metal silicates, guanidine-functionalized metal silicates, diatomaceous earth, surface-modified diatomaceous earth, guanidine-functionalized diatomaceous earth, gamma-FeO(OH), metal carbonates, metal phosphates, silica, perlite, guanidine-functionalized perlite, or a combination thereof. 
     Embodiment 22 is the method of any of embodiments 1 to 21, wherein the contacting includes passing the fluid sample through the nonwoven article using a sample delivery system. The system includes a freestanding container including a first reservoir and a deformable self-supporting receptacle dimensioned to be received in the first reservoir of the freestanding container and having a second reservoir, the freestanding container being more rigid than the deformable self-supporting receptacle. The freestanding container includes a base having an aperture formed therein through which the deformable self-supporting receptacle can be accessed. The passing includes applying external pressure to the deformable self-supporting receptacle via the aperture in the freestanding container to pass the fluid sample through the nonwoven article. 
     Embodiment 23 is the method of any of embodiments 1 to 22, wherein the nonwoven article includes a thickness of between 0.15 millimeters and 1 millimeter. 
     Embodiment 24 is the method of any of embodiments 1 to 23, wherein the nonwoven article includes a thickness of between 0.15 millimeters and 0.8 millimeters. 
     Embodiment 25 is the method of any of embodiments 1 to 24, wherein the polymeric fibers include a polyolefin, a polysulfone, a polyamide, or a combination thereof. 
     Embodiment 26 is the method of any of embodiments 1 to 25, wherein the polymeric fibers include bi-component fibers. 
     Embodiment 27 is the method of any of embodiments 1 to 26, wherein the polymeric fibers include a fibrillated polyolefin fiber. 
     Embodiment 28 is the method of any of embodiments 1 to 27, wherein the inorganic fibers include glass fibers, ceramic fibers, or a combination thereof. 
     Embodiment 29 is the method of any of embodiments 1 to 28, wherein the inorganic fibers include glass fibers. 
     Embodiment 30 is the method of any of embodiments 1 to 29, wherein the inorganic fibers and polymeric fibers include an average length of less than 50 millimeters. 
     Embodiment 31 is the method of any of embodiments 1 to 30, wherein the nonwoven article includes 5 to 60 weight percent concentration agent particles based on a total dried weight of the nonwoven article and 40 to 95 weight percent fibrous porous matrix based on the total dried weight of the nonwoven article. 
     Embodiment 32 is the method of any of embodiments 1 to 31, wherein the nonwoven article includes 20 to 50 weight percent concentration agent particles based on a total dried weight of the nonwoven article and 50 to 80 weight percent fibrous porous matrix based on the total dried weight of the nonwoven article. 
     Embodiment 33 is the method of any of embodiments 1 to 32, wherein the fibrous porous matrix is a nonwoven fibrous layer including uncrimped polymeric fibers. 
     Embodiment 34 is the method of embodiment 33, wherein the nonwoven fibrous layer includes polyolefin fibers and glass fibers. 
     Embodiment 35 is the method of any of embodiments 1 to 34, wherein the fibrous porous matrix is free of polyamide fibers. 
     Embodiment 36 is the method of any of embodiments 1 to 35, wherein the concentration agent particles include particles of amorphous metal silicates. 
     Embodiment 37 is the method of embodiment 36, wherein the concentration agent particles include particles of amorphous, spheroidized magnesium silicate. 
     Embodiment 38 is the method of embodiment 36 or embodiment 37, wherein the concentration agent particles include particles of amorphous, spherical aluminum silicate. 
     Embodiment 39 is the method of any of embodiments 36 to 38, wherein the concentration agent particles include particles of guanidine-functionalized metal silicates. 
     Embodiment 40 is the method of embodiment 39, wherein the concentration agent particles include particles of guanidine-functionalized magnesium silicate. 
     Embodiment 41 is the method of embodiment 39, wherein the concentration agent particles include particles of guanidine-functionalized aluminum silicate. 
     Embodiment 42 is the method of any of embodiments 1 to 41, wherein the concentration agent particles include particles of diatomaceous earth. 
     Embodiment 43 is the method of any of embodiments 1 to 42, wherein the concentration agent particles include particles of surface-modified diatomaceous earth, particles of guanidine-functionalized diatomaceous earth, or combinations thereof. 
     Embodiment 44 is the method of embodiment 43, wherein the surface-modified diatomaceous earth includes diatomaceous earth bearing, on at least a portion of its surface, a surface treatment including titanium dioxide, ferric oxide, fine-nanoscale gold or platinum, or a combination thereof. 
     Embodiment 45 is the method of any of embodiments 1 to 44, wherein the concentration agent particles include particles of gamma-FeO(OH). 
     Embodiment 46 is the method of any of embodiments 1 to 45, wherein the concentration agent particles include particles of perlite. 
     Embodiment 47 is the method of any of embodiments 1 to 46, wherein the concentration agent particles include particles of guanidine-functionalized perlite. 
     Embodiment 48 is the method of any of embodiments 1 to 47, wherein the concentration agent particles include particles of hydroxyapatite. 
     Embodiment 49 is the method of any of embodiments 1 to 48, wherein the particles are microparticles. 
     Embodiment 50 is a device for contacting a fluid sample with a nonwoven article. The device includes 1) a sample container, 2) a filter holder, 3) a nonwoven article, and 4) a first adaptor configured to interface the filter holder with a receptacle. The nonwoven article includes a) a fibrous porous matrix and b) a plurality of concentration agent particles enmeshed in the fibrous porous matrix. 
     Embodiment 51 is the device of embodiment 50, further including a second adaptor configured to attach the filter holder to a vacuum source, to a collection container, or to the sample container. 
     Embodiment 52 is the device of embodiment 50 or embodiment 51, further including a rotary pump attached to the filter holder or to the second adaptor. 
     Embodiment 53 is the device of any of embodiments 50 to 52, further including a gasket disposed on the nonwoven article. 
     Embodiment 54 is the device of embodiment 50 or embodiment 51, wherein the sample container includes a syringe. 
     Embodiment 55 is the device of embodiment 50, further including a syringe, the filter holder disposed between the syringe and the sample container. 
     Embodiment 56 is the device of embodiment 50, wherein the sample container includes a freestanding container including a first reservoir and a deformable self-supporting receptacle dimensioned to be received in the first reservoir of the freestanding container and having a second reservoir, the freestanding container being more rigid than the deformable self-supporting receptacle. The freestanding container includes a base having an aperture formed therein through which the deformable self-supporting receptacle can be accessed. The passing includes applying external pressure to the deformable self-supporting receptacle via the aperture in the freestanding container to pass the fluid sample through the nonwoven article. 
     Embodiment 57 is the device of any of embodiments 50 to 56, further including the receptacle, the receptacle configured to be operationally coupled to a luminometer. The receptacle contains at least one reagent. 
     Embodiment 58 is the device of any of embodiments 50 to 57, wherein the container has a volume of at least 50 milliliters. 
     Embodiment 59 is the device of any of embodiments 50 to 58, wherein the container has a volume of at least 150 milliliters. 
     Embodiment 60 is the device of any of embodiments 50 to 59, wherein the container has a volume of at least 300 milliliters. 
     Embodiment 61 is the device of any of embodiments 50 to 60, wherein the container has a volume of up to 1 liter. 
     Embodiment 62 is the device of any of embodiments 50 to 61, wherein the fibrous porous matrix consists essentially of inorganic fibers and polymeric fibers. 
     Embodiment 63 is the device of embodiment 62, wherein the polymeric fibers include a polyolefin, a polysulfone, a polyamide, or a combination thereof. 
     Embodiment 64 is the device of embodiment 62 or embodiment 63, wherein the polymeric fibers include bi-component fibers. 
     Embodiment 65 is the device of any of embodiments 62 to 64, wherein the polymeric fibers include a fibrillated polyolefin fiber. 
     Embodiment 66 is the device of any of embodiments 62 to 65, wherein the inorganic fibers include glass fibers, ceramic fibers, or a combination thereof. 
     Embodiment 67 is the device of embodiment 66, wherein the inorganic fibers include glass fibers. 
     Embodiment 68 is the device of any of embodiments 62 to 67, wherein the inorganic fibers and polymeric fibers include an average length of less than 50 millimeters. 
     Embodiment 69 is the device of any of embodiments 50 to 68, wherein the nonwoven article includes 5 to 60 weight percent concentration agent particles based on a total dried weight of the nonwoven article and 40 to 95 weight percent fibrous porous matrix based on the total dried weight of the nonwoven article. 
     Embodiment 70 is the device of any of embodiments 50 to 69, wherein the nonwoven article includes 20 to 50 weight percent concentration agent particles based on a total dried weight of the nonwoven article and 50 to 80 weight percent fibrous porous matrix based on the total dried weight of the nonwoven article. 
     Embodiment 71 is the device of any of embodiments 50 to 70, wherein the fibrous porous matrix is a nonwoven fibrous layer including uncrimped polymeric fibers. 
     Embodiment 72 is the device of any of embodiments 50 to 71, wherein the fibrous porous matrix is a nonwoven fibrous layer and the concentration agent particles are distributed throughout the nonwoven fibrous layer. 
     Embodiment 73 is the device of embodiment 72, wherein the nonwoven fibrous layer includes polyolefin fibers and glass fibers. 
     Embodiment 74 is the device of any of embodiments 50 to 73, wherein the fibrous porous matrix is free of polyamide fibers. 
     Embodiment 75 is the device of any of embodiments 50 to 74, wherein the concentration agent particles include amorphous metal silicates, guanidine-functionalized metal silicates, diatomaceous earth, surface-modified diatomaceous earth, guanidine-functionalized diatomaceous earth, gamma-FeO(OH), metal carbonates, metal phosphates, silica, perlite, guanidine-functionalized perlite, or a combination thereof. 
     Embodiment 76 is the device of any of embodiments 50 to 75, wherein the concentration agent particles include particles of amorphous metal silicates. 
     Embodiment 77 is the device of embodiment 75 or embodiment 76, wherein the concentration agent particles include particles of amorphous, spheroidized magnesium silicate. 
     Embodiment 78 is the device of any of embodiments 75 to 77, wherein the concentration agent particles include particles of amorphous, spherical aluminum silicate. 
     Embodiment 79 is the device of any of embodiments 75 to 78, wherein the concentration agent particles include particles of guanidine-functionalized metal silicates. 
     Embodiment 80 is the device of embodiment 79, wherein the concentration agent particles include particles of guanidine-functionalized magnesium silicate. 
     Embodiment 81 is the device of embodiment 79, wherein the concentration agent particles include particles of guanidine-functionalized aluminum silicate. 
     Embodiment 82 is the device of any of embodiments 50 to 81, wherein the concentration agent particles include particles of diatomaceous earth. 
     Embodiment 83 is the device of any of embodiments 50 to 82, wherein the concentration agent particles include particles of surface-modified diatomaceous earth, guanidine-functionalized diatomaceous earth, or a combination thereof. 
     Embodiment 84 is the device of embodiment 83, wherein the surface-modified diatomaceous earth includes diatomaceous earth bearing, on at least a portion of its surface, a surface treatment including titanium dioxide, ferric oxide, fine-nanoscale gold or platinum, or a combination thereof. 
     Embodiment 85 is the device of any of embodiments 50 to 84, wherein the concentration agent particles include particles of gamma-FeO(OH). 
     Embodiment 86 is the device of any of embodiments 50 to 85, wherein the concentration agent particles include particles of perlite. 
     Embodiment 87 is the device of any of embodiments 50 to 86, wherein the concentration agent particles include particles of guanidine-functionalized perlite. 
     Embodiment 88 is the device of any of embodiments 50 to 87, wherein the concentration agent particles include particles of hydroxyapatite. 
     Embodiment 89 is the device of any of embodiments 50 to 88, wherein the particles are microparticles. 
     Embodiment 90 is a kit including a) a device for contacting a fluid sample with a nonwoven article and b) a receptacle. The device includes 1) a sample container; 2) a filter holder; 3) a nonwoven article; and 4) a first adaptor. The first adaptor configured to interface the filter holder with the receptacle. The nonwoven article includes a) a fibrous porous matrix and b) a plurality of concentration agent particles enmeshed in the fibrous porous matrix. 
     Embodiment 91 is the kit of embodiment 90, further including a second adaptor configured to attach the filter holder to a vacuum source or to a collection container. 
     Embodiment 92 is the kit of embodiment 90 or embodiment 91, further including a rotary pump attached to the filter holder or to the second adaptor. 
     Embodiment 93 is the kit of any of embodiments 90 to 92, wherein the receptacle contains at least one reagent. 
     Embodiment 94 is the kit of any of embodiments 90 to 93, wherein the receptacle is configured to be operationally coupled to a luminometer. 
     Embodiment 95 is the kit of any of embodiments 90 to 94, further including instructions for using the kit. 
     Embodiment 96 is a device for contacting a fluid sample with a nonwoven article. The device includes 1) a sample container; 2) a filter holder configured to interface with a receptacle; and 3) a nonwoven article. The nonwoven article includes a) a fibrous porous matrix and b) a plurality of concentration agent particles enmeshed in the fibrous porous matrix. 
     Embodiment 97 is the device of embodiment 96, wherein the filter holder comprises an interior ledge configured to hold the nonwoven article. 
     Embodiment 98 is the device of embodiment 96 or embodiment 97, wherein the filter holder comprises an exterior ledge that is configured to interface with the receptacle. 
     Embodiment 99 is the device of any of embodiments 96 to 98, further including an adaptor configured to attach the filter holder to a vacuum source, to a collection container, or to the sample container. 
     Embodiment 100 is the device of embodiment 99, further including a rotary pump attached to the adaptor. 
     Embodiment 101 is the device of any of embodiments 96 to 98, further including a rotary pump attached to the filter holder. 
     Embodiment 102 is the device of any of embodiments 96 to 101, further including a gasket disposed on the nonwoven article. 
     Embodiment 103 is the device of embodiment 96, further including a syringe, the filter holder disposed between the syringe and the sample container. 
     Embodiment 104 is the device of any of embodiments 96 to 103, further including the receptacle, the receptacle configured to be operationally coupled to a luminometer. The receptacle contains at least one reagent. 
     Embodiment 105 is the device of any of embodiments 96 to 104, wherein the container has a volume of at least 50 milliliters. 
     Embodiment 106 is the device of any of embodiments 96 to 105, wherein the container has a volume of at least 150 milliliters. 
     Embodiment 107 is the device of any of embodiments 96 to 106, wherein the container has a volume of at least 300 milliliters. 
     Embodiment 108 is the device of any of embodiments 96 to 107, wherein the container has a volume of up to 1 liter. 
     Embodiment 109 is the device of any of embodiments 96 to 108, wherein the fibrous porous matrix consists essentially of inorganic fibers and polymeric fibers. 
     Embodiment 110 is the device of embodiment 109, wherein the polymeric fibers include a polyolefin, a polysulfone, a polyamide, or a combination thereof. 
     Embodiment 111 is the device of embodiment 109 or embodiment 110, wherein the polymeric fibers include bi-component fibers. 
     Embodiment 112 is the device of any of embodiments 108 to 111, wherein the polymeric fibers include a fibrillated polyolefin fiber. 
     Embodiment 113 is the device of any of embodiments 109 to 112, wherein the inorganic fibers include glass fibers, ceramic fibers, or a combination thereof. 
     Embodiment 114 is the device of embodiment 113, wherein the inorganic fibers include glass fibers. 
     Embodiment 115 is the device of any of embodiments 109 to 114, wherein the inorganic fibers and polymeric fibers include an average length of less than 50 millimeters. 
     Embodiment 116 is the device of any of embodiments 96 to 115, wherein the nonwoven article includes 5 to 60 weight percent concentration agent particles based on a total dried weight of the nonwoven article and 40 to 95 weight percent fibrous porous matrix based on the total dried weight of the nonwoven article. 
     Embodiment 117 is the device of any of embodiments 96 to 116, wherein the nonwoven article includes 20 to 50 weight percent concentration agent particles based on a total dried weight of the nonwoven article and 50 to 80 weight percent fibrous porous matrix based on the total dried weight of the nonwoven article. 
     Embodiment 118 is the device of any of embodiments 96 to 117, wherein the fibrous porous matrix is a nonwoven fibrous layer including uncrimped polymeric fibers. 
     Embodiment 119 is the device of any of embodiments 96 to 118, wherein the fibrous porous matrix is a nonwoven fibrous layer and the concentration agent particles are distributed throughout the nonwoven fibrous layer. 
     Embodiment 120 is the device of embodiment 119, wherein the nonwoven fibrous layer includes polyolefin fibers and glass fibers. 
     Embodiment 121 is the device of any of embodiments 96 to 120, wherein the fibrous porous matrix is free of polyamide fibers. 
     Embodiment 122 is the device of any of embodiments 96 to 121, wherein the concentration agent particles include amorphous metal silicates, guanidine-functionalized metal silicates, diatomaceous earth, surface-modified diatomaceous earth, guanidine-functionalized diatomaceous earth, gamma-FeO(OH), metal carbonates, metal phosphates, silica, perlite, guanidine-functionalized perlite, or a combination thereof. 
     Embodiment 123 is the device of any of embodiments 96 to 122, wherein the concentration agent particles include particles of amorphous metal silicates. 
     Embodiment 124 is the device of embodiment 122 or embodiment 123, wherein the concentration agent particles include particles of amorphous, spheroidized magnesium silicate. 
     Embodiment 125 is the device of any of embodiments 122 to 124, wherein the concentration agent particles include particles of amorphous, spherical aluminum silicate. 
     Embodiment 126 is the device of any of embodiments 122 to 125, wherein the concentration agent particles include particles of guanidine-functionalized metal silicates. 
     Embodiment 127 is the device of embodiment 126, wherein the concentration agent particles include particles of guanidine-functionalized magnesium silicate. 
     Embodiment 128 is the device of embodiment 126, wherein the concentration agent particles include particles of guanidine-functionalized aluminum silicate. 
     Embodiment 129 is the device of any of embodiments 96 to 128, wherein the concentration agent particles include particles of diatomaceous earth. 
     Embodiment 130 is the device of any of embodiments 96 to 129, wherein the concentration agent particles include particles of surface-modified diatomaceous earth, guanidine-functionalized diatomaceous earth, or combinations thereof. 
     Embodiment 131 is the device of embodiment 130, wherein the surface-modified diatomaceous earth includes diatomaceous earth bearing, on at least a portion of its surface, a surface treatment including titanium dioxide, ferric oxide, fine-nanoscale gold or platinum, or a combination thereof. 
     Embodiment 132 is the device of any of embodiments 96 to 131, wherein the concentration agent particles include particles of gamma-FeO(OH). 
     Embodiment 133 is the device of any of embodiments 96 to 132, wherein the concentration agent particles include particles of perlite. 
     Embodiment 134 is the device of any of embodiments 96 to 133, wherein the concentration agent particles include particles of guanidine-functionalized perlite. 
     Embodiment 135 is the device of any of embodiments 96 to 134, wherein the concentration agent particles include particles of hydroxyapatite. 
     Embodiment 136 is the device of any of embodiments 96 to 135, wherein the particles are microparticles. 
     Embodiment 137 is the device of embodiment 96 or embodiment 99, wherein the sample container includes a syringe. 
     Embodiment 138 is the device of any of embodiments 50 to 89 or 96 to 137, wherein the nonwoven article has a basis weight in the range of about 150 to about 350 grams per square meter (g/m 2 ). 
     Embodiment 139 is the method of any of embodiments 1 to 49, wherein the nonwoven article has a basis weight in the range of about 150 to about 350 grams per square meter (g/m 2 ). 
     Embodiment 140 is the kit of any of embodiments 90 to 95, wherein the nonwoven article has a basis weight in the range of about 150 to about 350 grams per square meter (g/m 2 ). 
     EXAMPLES 
     Unless otherwise noted, all chemicals used in the examples can be obtained from Sigma-Aldrich Corp. (Saint Louis, Mo.). Unless otherwise specified, all microbiological supplies and reagents were purchased as standard products from either Sigma-Aldrich or VWR. 
     
       
         
           
               
               
             
               
                   
               
               
                 Material 
                 Vendor 
               
               
                   
               
             
            
               
                 Fiber 1 - SHORT STUFF E380F ~0.7 mm 
                 MiniFIBERS, Inc.; Johnson City, TN 
               
               
                 average length, 15 microns diameter 
               
               
                 polyethylene fibers 
               
               
                 Fiber 2 - 6 denier 2 inches long chopped nylon 
                 MiniFIBERS, Inc.; Johnson City, TN 
               
               
                 fibers 
               
               
                 Fiber 3 - 1 denier bi-component ethylene vinyl 
                 MiniFIBERS, Inc.; Johnson City, TN 
               
               
                 acetate/polypropylene fibers 
               
               
                 Fiber 4 - long glass fibers (MICRO-STRAND 
                 Johns Mansville; Denver, CO 
               
               
                 106-475 Glass Fiberglas) Schuller Inc. 
               
               
                 Fiber 5 - 2 denier 5 mm bicomponent 
                 MiniFIBERS, Inc.; Johnson City, TN 
               
               
                 copolyester fibers made of polyester as the core 
               
               
                 and PET as the sheath 
               
               
                 Fiber 6 - typical length 4.3 mm (range 4.5-7.5 
                 CFF Fibrillated Fiber 114-3, from Sterling 
               
               
                 mm), specific gravity 1.17 acrylonitrile fibers 
                 Fibers, Inc.; Pace, FL 
               
               
                 CM-111 - Amorphous spheroidized magnesium 
                 3M Company; St. Paul, MN 
               
               
                 silicate: Cosmetic Microspheres (CM-111) 
               
               
                 G-CM-111 Guanylated CM-111 made according 
                 3M Company; St. Paul, MN 
               
               
                 to the method of Example E1-D in 
               
               
                 PCT/US2014/040861 
               
               
                 CLEAN-TRACE lysis reagent - reagent for 
                 3M Company; Bridgend, UK 
               
               
                 bioluminescence assay 
               
               
                 CLEAN-TRACE luciferin-luciferase enzyme 
                 3M Company; Bridgend, UK 
               
               
                 reagent - reagent for bioluminescence assay 
               
               
                 CLEAN-TRACE ATP Water Test 
                 3M Company; St. Paul, MN 
               
               
                 DI Water - Deionized filtered 18 megaohm 
                 Millipore; Waltham, MA 
               
               
                 water from a Milli-Q Gradient System 
               
               
                 ATP-free Water - HYPURE Molecular biology 
                 Thermo Fisher Scientific; Waltham, MA 
               
               
                 grade water catalog # SH30538.02 
               
               
                 Tryptic Soy Broth - DIFCO Tryptic Soy Broth, 
                 Becton Dickenson; Sparks, MD 
               
               
                 prepared at 3% according to the manufacturer&#39;s 
               
               
                 instructions 
               
               
                   E. coli /coliform count plate - 3M PETRIFILM 
                 3M Company; St. Paul, MN 
               
               
                   E coli /Coliform Count Plates; 
               
               
                 Aerobic count plate - 3M PETRIFILM Aerobic 
                 3M Company; St. Paul, MN 
               
               
                 Count Plates 
               
               
                 Endo Agar plate - Premade agar plate, Catalog # 
                 Becton Dickenson; Sparks, MD 
               
               
                 254016 
               
               
                 3M Flip-Top Dilution Bottle with Butterfield&#39;s 
                 3M Company; St. Paul, MN 
               
               
                 Buffer (Catalog Number FTBFD9966) 
               
               
                 3M CLEAN-TRACE Water Plus - Total ATP, 
                 3M Company; St. Paul MN 
               
               
                 Catalog # AQT200 
               
               
                 3M CLEAN-TRACE Surface ATP, Catalog # 
                 3M Company; St. Paul MN 
               
               
                 UXL100 
               
               
                   
               
            
           
         
       
     
     Preparation of Nonwoven Fibrous Porous Matrices Containing Calcined Magnesium Silicate 
     Examples 1, 2 and 3 
     Fiber premixes were prepared by mixing various amounts of Fiber 1, Fiber 2, Fiber 3, and Fiber 4 as shown in Table 1 below. The fibers were added to 3 liters of cold deionized water in a 4 L blender (available from VWR, Radnor, Pa., under the trade designation “WARING COMMERCIAL HEAVY DUTY BLENDER, MODEL 37BL84”) and blended at low speed for 30 seconds. The mixture was examined for uniform dispersion of the fibers without nits or clumps. The additive particles, CM-111, were added with an additional liter of deionized water and mixed at low speed for 15 seconds. 
     A felt was prepared using a pad maker apparatus (obtained from Williams Apparatus, Watertown, N.Y., under the trade designation “TAPPI”) that had a box measuring about 30 centimeters (12 inches) square and 30 centimeters (˜12 inches) high with a fine mesh screen at the bottom and a drain valve. On the screen ˜a 14 inch (36 cm)×12 inch (30 cm) piece of a polyethylene spunbond (PET Lutradur 7240 obtained from Fiberweb, Cincinnati, Ohio) was laid as scrim on the screen. The box was filled with tap water up to a height of about 1 centimeter above the screen. Each fiber and particle mixture was poured into the box and the valve was opened immediately which created a vacuum that pulled the water out of the box. 
     The fibrous nonwoven felts were each transferred from the apparatus onto a 20 centimeter square sheet of blotter paper (96-pound white paper, obtained from Anchor Paper, St. Paul, Minn.). Each felt was sandwiched between 2 to 4 layers of blotter paper, to blot excess water. The pressed felt was then transferred onto a fresh sheet of blotter paper and placed in an oven (obtained from SPX Thermal Product Solutions, White Deer, Pa., under the trade designation “BLUE M STABIL-THERM OVEN, MODEL OV-560A2”) set at 110° C. for about 3 hours to remove residual water and to form a nonwoven fibrous porous matrix. The resulting fibrous porous matrices of Examples 1 and 2 were approximately 0.8-1 millimeter thick. The fibrous porous matrix of Example 3 was approximately 0.8-0.9 millimeters thick. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Compositions of Examples 1-3 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Materials (in grams) 
                 Example 1 
                 Example 2 
                 Example 3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Fiber 1 
                 11.08 
                 10.98 
                 8.83 
               
               
                   
                 Fiber 2 
                 3.01 
                 0 
                 2.44 
               
               
                   
                 Fiber 3 
                 2.30 
                 2.29 
                 1.82 
               
               
                   
                 Fiber 4 
                 0 
                 1.8 
                 1.4 
               
               
                   
                 CM-111 
                 5.15 
                 5.07 
                 5.03 
               
               
                   
                 Basis weight (g/m 2 ) 
                 196.66 
                 203.44 
                 197.74 
               
               
                   
                   
               
            
           
         
       
     
     Preparation of Nonwoven Fibrous Porous Matrices Containing Guanylated Magnesium Silicate 
     Examples 4, 5, 6, 7 and 8 
     Nonwoven fibrous porous matrices of Examples 4, 5, 6, 7, and 8 were made using the procedure described above. The formulations are shown in Table 2 below. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Compositions of Examples 4-8 
               
            
           
           
               
               
               
               
               
               
            
               
                 Materials 
                 Example 
                 Example 
                 Example 
                 Example 
                 Example 
               
               
                 (in grams) 
                 4 
                 5 
                 6 
                 7 
                 8 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Fiber 1 
                 11.05 
                 11.03 
                 11.08 
                 11.05 
                 11.01 
               
               
                 Fiber 2 
                 0 
                 0 
                 3.02 
                 3.03 
                 3.01 
               
               
                 Fiber 3 
                 2.26 
                 2.25 
                 2.27 
                 2.25 
                 2.26 
               
               
                 Fiber 4 
                 0 
                 2.25 
                 1.76 
                 0 
                 1.76 
               
               
                 Guanylated 
                 5.00 
                 5.00 
                 5.01 
                 5.00 
                 5.00 
               
               
                 CM-111 
               
               
                 Basis 
                 166.30 
                 217.07 
                 238.32 
                 199.02 
                 229.82 
               
               
                 weight 
               
               
                 (g/m 2 ) 
               
               
                   
               
            
           
         
       
     
     The thickness of the matrix of Example 4 was approximately 0.8-0.9 mm, Example 5 was approximately 0.6-0.8 mm thick, and Examples 6-8 were each approximately 0.8-1.0 mm thick. 
     Example 9: Bacteria Used in Examples 
     The various bacteria used in the examples (see Table 3 below) were obtained from ATCC (Manassas, Va.). 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Bacteria used in examples 
               
            
           
           
               
               
               
            
               
                   
                 Bacteria 
                 ATCC No. 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 
                   Escherichia coli 
                 
                 51813 
               
               
                   
                 
                   Staphylococcus aureus 
                 
                 6538 
               
               
                   
                 
                   Enterobacter aerogenes 
                 
                 29007 
               
               
                   
                 
                   Pseudomonas aeruginosa 
                 
                 9027 
               
               
                   
                   
               
            
           
         
       
     
     Pure cultures of the bacterial strains were inoculated into Tryptic Soy Broth (TSB, Becton, Dickinson and Company, Franklin Lakes, N.J.) and were grown overnight at 37° C. The cultures were diluted serially in Butterfield phosphate buffer (3M Company, St. Paul, Minn.) to obtain desired amount of colony forming units (cfu) per ml for spiking into water samples.  E. coli  and  E. aerogenes  were quantified by plating appropriate dilutions on 3M PETRIFILM  E. coli /Coliform Count Plates (3M Company) according to manufacturer&#39;s instructions and incubated overnight at 37° C.  S. aureus  and  P. aeruginosa  were quantified by plating appropriate dilutions on 3M PETRIFILM aerobic count plates (3M Company) and incubated overnight at 37° C. The plates were read using 3M PETRIFILM Plate Reader (3M Company) and colony forming units (cfu) were determined. 
     Example 10: Bacterial Capture Efficiency of Nonwoven Fibrous Porous Matrices 
     100 ml of either neutralized tap water (neutralized with 0.1% sodium thiosulfate) or 18 mega ohms double deionized water was spiked with various bacteria to get approximately 100 cfu/ml (total of approximately 10,000 cfu in 100 ml). A 14 mm disk was cut from the various nonwoven fibrous porous matrices described above and the disk was placed in a SWINNEX 13 Filter Holder (Catalog number SX0001300, EMD Millipore, Billerica, Mass.). The filter holder was closed and attached to a 60 mL BD syringe with BD LUER-LOK tip (Product Number 309653, Becton, Dickinson and Company). The plunger from the syringe was removed prior to attaching the filter holder. The syringe was connected to a 12-place Waters Millipore SEP-PAK vacuum manifold (Waters Corporation, Milford, Mass.). A collection tube was placed in the sample rack to collect the filtrate from each of the syringes. The vacuum manifold was attached to Air Cadet Vacuum/Pressure Station (model No. 420-3901, Barnant Company, Barrington, Ill.) and the solution was filtered through the fibrous porous matrix materials at a vacuum pressure of about 15 inches of mercury. The filtration took less than a minute. For manual filtration, the samples were also filtered by pushing the syringe plunger through the barrel. 
     The filtrate from each of the filtrations was collected in sterile tubes and 1 ml of each was plated on PETRIFILM plates to enumerate the amount of bacteria left over in the solution. The plates were incubated overnight at 37° C. and colonies growing on the plates were enumerated. The input sample was also plated prior to filtration to determine the amount of bacteria in the sample. The samples were plated on a minimum of three plates and experiments were repeated at least three times. The number of bacteria in the input solution and the number of bacteria left over in the filtrate was used to calculate the percent capture efficiency. The bacterial capture ranged from 32 to 95 percent depending on the material (see Tables 4, 5, 6 and 7 below). The nonwoven fibrous porous matrices without fiberglass (Fiber 4, Examples 1 and 4) ranged from 32 to 70%. The percent capture of the nonwoven fibrous porous matrices without nylon (Fiber 2, Examples 2 and 5) ranged from 90 to 95%. Similar results were seen with  E. aerogenes  and  P. aeruginosa  (see Tables 4 and 6). 
     The percent capture of bacteria in nonwoven fibrous porous matrices without Fiber 2 (nylon) indicated that it was not essential for bacterial capture. However, Fiber 4 (fiberglass) was more important as the percent capture dropped to 32 to 70% when Fiber 4 (Examples 1 and 4) was removed. This was the case with nonwoven fibrous porous matrices containing either type of particles (calcined magnesium silicate or guanylated magnesium silicate). 
     Example 11: Detection of Bacteria in Nonwoven Fibrous Porous Matrices by ATP Bioluminescence 
     Each nonwoven fibrous porous matrix containing bound bacteria was removed from the SWINNEX filter holder and transferred aseptically to a 1.5 ml microfuge tube (Plastibrand microtubes, Brand GmbH &amp; Co. KG, Wertheim, Germany). 200 microliters of CLEAN-TRACE lysis reagent containing bacterial lysis reagent was added to the tube and vortexed for 1 min and allowed to sit at room temperature for additional 1 minute. 250 microliters of CLEAN-TRACE luciferin-luciferase enzyme reagent was added to the tube and mixed. The tube was placed immediately into a bench-top luminometer (20/20n single tube luminometer, Turner Biosystems, Sunnyvale, Calif.) and measurement of RLUs was recorded. The luminescence measurements were obtained from the luminometer using spreadsheet interface PC software that was provided with the luminometer. 100 microliters of buffer containing approximately 10,000 cfu of bacteria was pipetted into a 1.5 ml microfuge tube (Plastibrand microtubes) and upon addition of lysis mix (200 microliters) and ATP reagent (250 microliters), luminescence was measured similarly. The relative light units obtained from approximately 10,000 cfu was used to calculate percent recovery of ATP in nonwoven fibrous porous matrices (see Tables 4 and 5 below). The ATP recovery varied from 30 to 68% with uncut material and the matrix without Fiber 2 (Examples 2 and 5) gave the most recovery (55 to 68%). 
     
       
         
           
               
             
               
                 TABLE 4 
               
               
                   
               
               
                 Bacterial capture efficiency and percent recovery 
               
               
                 of ATP in uncut nonwoven fibrous porous matrices 
               
               
                 containing calcined magnesium silicate 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 EC_10,000 cfu total 
                   
                 SA_10,000 cfu total 
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 % ATP 
                   
                 % ATP 
               
               
                 Matrix 
                 % Capture 
                 Recovery 
                 % Capture 
                 Recovery 
               
               
                   
               
               
                 Example 1 
                 60 
                 32 
                 32 
                 30 
               
               
                 Example 2 
                 94 
                 62 
                 92 
                 60 
               
               
                 Example 3 
                 77 
                 48 
                 85 
                 45 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 EA_10,000 cfu total 
                   
                 PA_10,000 cfu total 
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 % ATP 
                   
                 % ATP 
               
               
                   
                 % Capture 
                 Recovery 
                 % Capture 
                 Recovery 
               
               
                   
               
               
                 Example 1 
                 48 
                 35 
                 38 
                 30 
               
               
                 Example 2 
                 95 
                 55 
                 90 
                 58 
               
               
                 Example 3 
                 65 
                 35 
                 62 
                 30 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 Bacterial capture efficiency and percent recovery 
               
               
                 of ATP in uncut nonwoven fibrous porous matrices 
               
               
                 containing guanylated magnesium silicate 
               
            
           
           
               
               
               
               
               
            
               
                   
                 EC_10,000 cfu total 
                   
                 SA_10,000 cfu total 
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 % ATP 
                   
                 % ATP 
               
               
                 Matrix 
                 % Capture 
                 Recovery 
                 % Capture 
                 Recovery 
               
               
                   
               
               
                 Example 4 
                 60 
                 56 
                 70 
                 55 
               
               
                 Example 5 
                 93 
                 65 
                 95 
                 68 
               
               
                 Example 6 
                 85 
                 46 
                 91 
                 49 
               
               
                   
               
            
           
         
       
     
     In another experiment, the nonwoven fibrous porous matrix was aseptically cut into small pieces and then transferred to 1.5 ml microfuge tube (Plastibrand microtubes). 200 microliters of the lysis reagent was added to the tube and vortexed for 1 minute and allowed to sit at room temperature for additional 1 minute. 250 microliters of the luciferin-luciferase enzyme reagent was added to the tube and mixed. The luminescence was measured as described above. The percent recovery of ATP in nonwoven fibrous porous matrices is shown in Tables 6 and 7 below. The ATP recovery varied from 52 to 77% with uncut material and the wet-laid without Fiber 2 (Examples 2 and 5) gave the most recovery (65 to 77%). 
     
       
         
           
               
             
               
                 TABLE 6 
               
               
                   
               
               
                 Bacterial capture efficiency and percent recovery of ATP in cut 
               
               
                 fibrous porous matrices containing calcined magnesium silicate 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 EC_10,000 cfu total 
                   
                 SA_10,000 cfu total 
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 % ATP 
                   
                 % ATP 
               
               
                 Matrix 
                 % Capture 
                 Recovery 
                 % Capture 
                 Recovery 
               
               
                   
               
               
                 Example 1 
                 55 
                 60 
                 45 
                 55 
               
               
                 Example 2 
                 92 
                 77 
                 90 
                 70 
               
               
                 Example 3 
                 75 
                 65 
                 82 
                 72 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 EA_10,000 cfu total 
                   
                 PA_10,000 cfu total 
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 % ATP 
                   
                 % ATP 
               
               
                   
                 % Capture 
                 Recovery 
                 % Capture 
                 Recovery 
               
               
                   
               
               
                 Example 1 
                 45 
                 55 
                 35 
                 40 
               
               
                 Example 2 
                 90 
                 68 
                 90 
                 65 
               
               
                 Example 3 
                 68 
                 52 
                 65 
                 55 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 Bacterial capture efficiency and percent recovery of ATP in cut 
               
               
                 fibrous porous matrices containing guanylated magnesium silicate 
               
            
           
           
               
               
               
               
               
            
               
                   
                 EC_10,000 cfu total 
                   
                 SA_10,000 cfu total 
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 % ATP 
                   
                 % ATP 
               
               
                 Matrix 
                 % Capture 
                 Recovery 
                 % Capture 
                 Recovery 
               
               
                   
               
               
                 Example 4 
                 62 
                 55 
                 68 
                 57 
               
               
                 Example 5 
                 91 
                 68 
                 90 
                 70 
               
               
                 Example 6 
                 83 
                 52 
                 88 
                 45 
               
               
                   
               
            
           
         
       
     
     Example 12: Bacterial Capture and Detection of ATP with Integrated Devices 
     The container, filter holder and second adaptors were constructed from a CAD drawing using a UV curable epoxy composition (ACCURA 60 epoxy resin) in a stereolithography machine (SLA Model SLA-250/40 machine) according to the manufacturer&#39;s instructions. The devices were formed according to ( FIGS. 2E and 3E ) but did not include first adaptors. The epoxy composition and the machine were manufactured by 3D Systems Corporation; Rock Hill S.C.). 
     Each filtration device was formed as three separate parts. The filter holder holds a 12 mm disk and has threads to screw it to the container. The second adaptor has threads to connect it to the filter holder and the entire device assemblies are shown in  FIGS. 2E and 3E . The second adaptor  22  in  FIG. 2E  has a long stem and was attached to a stopper to connect the entire device assembly to a vacuum flask or a manifold. The second adaptor  22  in  FIG. 3E  has threads to connect it to a collection container and has a side arm to connect it to a vacuum source. 
     The filtration device according to  FIG. 2E  (not including a first adaptor) was assembled using parts made by SLA and a 12 mm nonwoven fibrous porous matrix disk (one of the matrices of Examples 1, 2, or 3) was placed at the bottom of the filter holder before connecting the filter holder to the second adaptor. The filter holder with the second adaptor was connected to the container and the entire device was connected to a vacuum flask. A 100 ml fluid sample containing approximately 10,000 cfu total (approximately 100 cfu/ml) of bacteria was added to the container and filtered using the vacuum station (Air Cadet Vacuum/Pressure Station, model No. 420-3901, Barnant Company). The filtrate was collected and plated to determine capture efficiency as described in Example 10. The assembly was disconnected from the vacuum flask, the filter holder was removed and the filter holder was interfaced to the 3M CLEAN-TRACE Water Plus—Total ATP detection device. The handle from the ATP detection device was removed and the filter holder was placed on top of the tube. The fibrous porous matrix disk (i.e., filter) was pushed down into the tube using the handle and then the filter holder was removed. The handle was returned to the detection device and the disk was pushed all the way down into the detection chamber. The device was shaken for about 2 minutes and then inserted into a 3M CLEAN-TRACE NG luminometer to determine the RLU. The results are shown in Table 8 below. 
     
       
         
           
               
             
               
                 TABLE 8 
               
             
            
               
                   
               
               
                 Bacterial capture efficiency and percent recovery of 
               
               
                 ATP in fibrous porous matrices containing calcined magnesium 
               
               
                 silicate using filtration device of FIG. 2E. 
               
            
           
           
               
               
               
               
               
            
               
                   
                 EC_10,000 cfu total 
                   
                 SA_10,000 cfu total 
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 % ATP 
                   
                 % ATP 
               
               
                 Matrix 
                 % Capture 
                 Recovery 
                 % Capture 
                 Recovery 
               
               
                   
               
               
                 Example 1 
                 55 
                 35 
                 45 
                 28 
               
               
                 Example 2 
                 88 
                 60 
                 90 
                 55 
               
               
                 Example 3 
                 82 
                 45 
                 80 
                 40 
               
               
                   
               
            
           
         
       
     
     The filtration device according to  FIG. 3E  (not including a first adaptor) was assembled and contained a 12 mm wet-laid disk (one of the matrices of Examples 1, 2, or 3). The assembled device was connected to a bottle and a 100 ml fluid sample containing approximately 10,000 cfu total (approximately 100 cfu/ml) of bacteria was added to the container and filtered using the vacuum station (Air Cadet Vacuum/Pressure Station, model No. 420-3901, Bamant Company). The filtrate was collected and plated to determine capture efficiency as described in Example 10. The assembly was disconnected from the vacuum flask, the filter holder was removed and the filter holder was interfaced to the 3M CLEAN-TRACE Water Plus—Total ATP detection device. The handle from the ATP detection device was removed and the filter holder was placed on top of the tube. The fibrous porous matrix disk (i.e., filter) was pushed down into the tube using the handle and then the filter holder was removed. The handle was returned to the detection device and the disk was pushed all the way down into the detection chamber. The device was shaken for about 2 minutes and then inserted into a 3M CLEAN-TRACE NG luminometer to determine the RLU. The results are shown in Table 9 below. 
     
       
         
           
               
             
               
                 TABLE 9 
               
             
            
               
                   
               
               
                 Bacterial capture efficiency and percent recovery of ATP 
               
               
                 in fibrous porous matrices containing calcined magnesium 
               
               
                 silicate using the filtration device of FIG. 3E. 
               
            
           
           
               
               
               
               
               
            
               
                   
                 EC_10,000 cfu total 
                   
                 SA_10,000 cfu total 
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 % ATP 
                   
                 % ATP 
               
               
                 Matrix 
                 % Capture 
                 Recovery 
                 % Capture 
                 Recovery 
               
               
                   
               
               
                 Example 1 
                 48 
                 30 
                 40 
                 26 
               
               
                 Example 2 
                 85 
                 65 
                 88 
                 58 
               
               
                 Example 3 
                 75 
                 40 
                 84 
                 42 
               
               
                   
               
            
           
         
       
     
     Example 13: Testing of Fibrous Porous Matrices with Various Formulations for Removal of  E. coli  from Water Samples by Filtration 
     A streaked culture of  E. coli  (ATCC 11229) on a TSA was incubated overnight at 37° C. From the plate an isolated colony was removed and inoculated into 5 ml of TSB using a standard microbiology loop and incubated in a shaking incubator (INNOVA 44 from New Brunswick Scientific) at 37° C. for 20-22 hours. The overnight culture that contained ˜2-3×10 9  cfu/ml was serially diluted in Butterfield&#39;s Buffer to obtain an inoculum with approximately 1×10 6  cfu/mL. 
     A test sample was prepared by inoculating 200 ml deionized of water (MilliQ Gradient system, Millipore, Ma) a 1:100 dilution of the 10 6  cfu/mL inoculum resulting in water test sample containing approximately 10 4  cfu/ml (˜4 Log cfus/ml). 
     A disk 47 mm in diameter was die punched from each of the nonwoven fibrous porous matrices of Examples 4, 5, 7, and 8, and each placed into a sample holder which was a custom device fabricated from polycarbonate. The device had three parts and was cylindrically shaped measuring about 60 cm in diameter by about 45 cm high. The lower part contained a support screen for the filter disk and a sample outlet port. The top portion was enclosed except for the sample inlet port through PVC tubing connected to the Cole Parmer peristaltic pump (Model No. 7553-70) and was vented on the upstream side to allow for of purging air. O-ring seals were used to prevent leakage on both the upstream and downstream sides. Internal threads provided closure pressure. The 47 mm disk was placed on top of the support screen, an O ring was added on top and holder was closed. 
     The fibrous porous matrices were tested individually, without replicates. A pre-filtration sample was pumped through the sample holder containing the nonwoven matrix disk using a Cole Parmer peristaltic pump (Model No. 7553-70) using ⅛″ wall thick PVC tubing (VWR catalog #60985-522). The spiked water was pumped through the fibrous porous matrix at a flow rate of 12 ml/minute. Filtrates were collected in 250 ml sterile glass bottles. The first 100 ml filtrate was collected and discarded. The second 100 ml filtrate was collected for further processing. After each filtration test, the holder was disassembled to remove the fibrous porous matrix using sterile forceps. Between testing of the matrices the filtration device was rinsed with filtered sterilized 500 ml deionized water. 
     A 10 ml volume of the second 100 ml filtrate was added to a 100 ml containing Butterfield&#39;s Buffer flip-top bottle to obtain a 1:10 dilution. The bottle was capped and mixed manually by shaking for 10 seconds. A 10 ml volume was removed and added to another flip-top bottle to obtain a 1:100. Similarly the filtrate was further diluted to 1:1000 and 1:10000. These 100 ml diluted filtrates were vacuum filtered through 0.45 micron filters. After each filtration, the vacuum apparatus was rinsed with filtered sterilized 500 ml deionized water and blotted dry with Kimwipes (Kimtech Science Delicate Task Wipers, Kimberly-Clark Professional, Roswell, Ga.). 
     The matrices were removed from the apparatus with sterile forceps plates and placed on Endo Agar plates, grid side up. The plates were incubated at 37° C. for 18-20 hours. Colony counts were obtained from plates by manual counting. Pre-filtration samples were also diluted and filtered as the procedure above. The cfu/ml colony counts were converted to Log cfu/ml values. Log Reduction Values (LRV) were calculated based on counts obtained from the plated filtrate and pre-filtration samples by using the formula below. 
       LRV=(Log of cfus/ml in pre-filtration sample)−(Log of cfus/ml in filtrate sample)
 
     Filtration testing was done on 47 mm disks of the matrices of Examples 4, 5, 7, and 8. The results are shown in Table 10 below. 
     
       
         
           
               
             
               
                 TABLE 10 
               
             
            
               
                   
               
               
                 Removal of  E. coli  with fibrous porous matrices 
               
               
                 containing guanylated magnesium silicate. 
               
            
           
           
               
               
               
               
            
               
                   
                 Matrix 
                 Log cfus in pre-filtration sample 
                 LRV 
               
               
                   
                   
               
               
                   
                 Example 4 
                 4.53 
                 3.53 
               
               
                   
                 Example 5 
                 4.53 
                 3.53 
               
               
                   
                 Example 7 
                 4.53 
                 3.53 
               
               
                   
                 Example 8 
                 4.53 
                 4.53 
               
               
                   
                   
               
            
           
         
       
     
     Preparation of Nonwoven Fibrous Porous Matrices Containing Guanylated Perlite or Calcined Magnesium Silicate 
     Examples 14, 15, 16, 17 and 18 
     Nonwoven fibrous porous matrices of Examples 14, 15, 16, 17 and 18 were made using the procedure described in Examples 1, 2 and 3. The formulations are shown in Table 11 below. The thickness of the matrix of Example 14 was approximately 2.0 to 2.3 mm, Example 15 was approximately 1.2 to 1.5 mm, Example 16 was approximately 0.65 to 0.85 mm, Example 17 was approximately 0.6 to 0.8 mm, and Example 18 was approximately 0.6 to 0.8 mm thick. 
                     TABLE 11                  Compositions of Examples 14-18                                     Materials   Example   Example   Example   Example   Example       (in grams)   14   15   16   17   18                                             Fiber 1   11.08   8.44   8.45   6.6   6.6       Fiber 2   3.01   2.45   0   0   0       Fiber 3   2.30   1.89   1.86   1.34   1.38       Fiber 4   1.84   1.47   1.47   1.07   1.06       CM-111   0   0   0   0   4.0       Guanylated   5.0   4.09   4.0   3.99   0       perlite                    
Preparation of Nonwoven Fibrous Porous Matrices Containing Guanylated Perlite with Autoclaved Components
 
     Examples 19, 20 and 21 
     Nonwoven fibrous porous matrices of Examples 19, 20 and 21 were made using the procedure described in Examples 1, 2 and 3. The formulations are shown in Table 12 below. The components were autoclaved at 121° C. for 30 minutes (AMSCO CENTURY Scientific model SV-120 pressure sterilizer, Steris Corporation, Mentor, Ohio) and then mixed with sterile water for preparation of matrix as described before. Fiber 3 (bi-component ethylene vinyl acetate/polypropylene fiber) lost its consistency during autoclaving and its addition gave a matrix which was very fragile. The thickness of the matrix of Example 19 was approximately 0.4 to 0.6 mm, Example 20 was approximately 0.4 to 0.6 mm, and Example 21 was approximately 0.8 to 1.0 mm thick. 
     
       
         
           
               
             
               
                 TABLE 12 
               
             
            
               
                   
               
               
                 Compositions of Examples 19-21 
               
            
           
           
               
               
               
               
            
               
                 Materials (in grams) 
                 Example 19 
                 Example 20 
                 Example 21 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 Fiber 1 (autoclaved) 
                 8.44 
                 8.46 
                 8.46 
               
               
                 Fiber 2 (autoclaved) 
                 0 
                 0 
                 0 
               
               
                 Fiber 3 (autoclaved) 
                 1.87 
                 1.89 
                 0 
               
               
                 Fiber 3 
                 0 
                 0 
                 1.87 
               
               
                 Fiber 4 (autoclaved) 
                 1.47 
                 1.47 
                 1.48 
               
               
                 Guanylated perlite 
                 3.97 
                 0 
                 4.01 
               
               
                 (autoclaved) 
               
               
                 Guanylated perlite 
                 0 
                 4.0 
                 0 
               
               
                   
               
            
           
         
       
     
     Example 22: Bacterial Capture Efficiency of Nonwoven Fibrous Porous Matrices from Example 14 to Example 21 
     The capture efficiency of nonwoven fibrous porous matrices prepared in Examples 14 to 21 were tested as described in Example 10. The number of bacteria in the input solution and the number of bacteria left over in the filtrate was used to calculate the percent capture efficiency. The bacterial capture ranged from 88 to 99 percent depending on the material (see Table 13 below). Again, fibrous matrices without Fiber 2 (nylon) did not show any appreciable difference in percent capture. The matrices prepared with autoclaved materials showed similar recoveries as non-autoclaved material. 
     Example 23: Detection of Bacteria in Nonwoven Fibrous Porous Matrices by ATP Bioluminescence 
     ATP bioluminescence from each nonwoven fibrous porous matrix (Examples 14 to 21) containing bound bacteria was tested as described in Example 11. The relative light units obtained from input bacteria (approximately 10,000 cfu) was used to calculate percent recovery of ATP in the nonwoven fibrous porous matrices (see Table 13 below). The ATP recovery varied from 38 to 82% and the matrices without Fiber 2 (Examples 16 to 21) gave the most recovery (60 to 82%). 
     
       
         
           
               
             
               
                 TABLE 13 
               
             
            
               
                   
               
               
                 Bacterial capture efficiency and percent recovery 
               
               
                 of ATP with nonwoven fibrous porous matrices 
               
            
           
           
               
               
               
            
               
                   
                 EC_10,000 cfu total 
                 SA_10,000 cfu total 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 % ATP 
                   
                 % ATP 
               
               
                 Matrix 
                 % Capture 
                 Recovery 
                 % Capture 
                 Recovery 
               
               
                   
               
               
                 Example 14 
                 99 
                 45 
                 98 
                 38 
               
               
                 Example 15 
                 96 
                 48 
                 92 
                 42 
               
               
                 Example 16 
                 94 
                 72 
                 95 
                 68 
               
               
                 Example 17 
                 96 
                 82 
                 95 
                 73 
               
               
                 Example 18 
                 99 
                 65 
                 92 
                 58 
               
               
                 Example 19 
                 99 
                 75 
                 93 
                 62 
               
               
                 Example 20 
                 97 
                 68 
                 90 
                 60 
               
               
                 Example 21 
                 91 
                 65 
                 88 
                 65 
               
               
                   
               
            
           
         
       
     
     Example 24: Bacterial Capture and Detection of ATP with Paint Preparation Device 
     A 3M PPS (paint preparation system) containing cup, collar, disposable liner and lid was obtained from 3M Company. A filter adapter was constructed from a CAD drawing using a UV curable epoxy composition (ACCURA 60 epoxy resin) in a stereolithography machine (SLA Model SLA-250/40 machine) according to the manufacturer&#39;s instructions. The devices were formed according to  FIGS. 7D and 7E . The epoxy composition and the machine were manufactured by 3D Systems Corporation). 
     The filter adapter holds a 14 mm disk and couples to the disposable lid. The filter adaptor has a built-in cylindrical cavity to hold a cylinder beneath the fibrous porous matrix. The PPS device with filter adaptor containing a fibrous porous matrix (of Example 14, 15, 16 or 17) was assembled according to  FIGS. 7D and 7E . A 100 ml fluid sample containing approximately 10,000 cfu total (˜100 cfu/ml) of bacteria was added to the liner in the cup, closed with the lid coupled with the filter adaptor, and sealed with the collar. The device was inverted and the liner was pushed using a plunger from a syringe, to push the fluid sample through the fibrous porous matrix. The filtrate was collected and plated to determine capture efficiency as described in Example 10. 
     The filter adaptor was removed from PPS, the fibrous porous matrix was pushed into the cylinder using a 3M CLEAN-TRACE Surface ATP swab, and the cylinder with the fibrous matrix was lifted with the handle of the swab. The CLEAN-TRACE Surface ATP swab contains lysis reagent in the swab. The swab was introduced into a 3M CLEAN-TRACE Water Plus—Total ATP Detection Device (3M Company) and pushed into the detection chamber ( FIGS. 8A to 8D ). The detection device containing the fibrous matrix was shaken for 1 to 2 min and then inserted into a 3M CLEAN-TRACE NG luminometer (3M Company) ( FIG. 8E ) for measuring bioluminescence. 
     The bacterial capture ranged from 92 to 99 percent and was similar to using a SWINNEX 13 Filter Holder (see Table 14 below). The ATP recovery varied from 32 to 75% and the matrices without Fiber 2 (Examples 16 and 17) gave the most recovery (65 to 75%). 
     
       
         
           
               
             
               
                 TABLE 14 
               
             
            
               
                   
               
               
                 Bacterial capture efficiency and percent recovery of ATP in fibrous 
               
               
                 porous matrices using the filtration device of FIG. 7D. 
               
            
           
           
               
               
               
            
               
                   
                 EC_10,000 cfu total 
                 SA_10,000 cfu total 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 % ATP 
                   
                 % ATP 
               
               
                 Matrix 
                 % Capture 
                 Recovery 
                 % Capture 
                 Recovery 
               
               
                   
               
               
                 Example 14 
                 99 
                 32 
                 98 
                 33 
               
               
                 Example 15 
                 96 
                 45 
                 95 
                 38 
               
               
                 Example 16 
                 92 
                 70 
                 93 
                 65 
               
               
                 Example 17 
                 95 
                 75 
                 92 
                 68 
               
               
                   
               
            
           
         
       
     
     Examples 25-28 and Comparative Examples 1 and 2: Bacterial Capture and Detection of ATP with Device Including a Syringe Adaptor 
     Produced water samples were obtained from an oil well in Canada. A device as illustrated in  FIG. 9F  was assembled, in which 10 ml of a produced water sample D (i.e., Comparative Example 1) was loaded into a 10 cubic centimeter syringe and a 14-mm diameter disk of the nonwoven fibrous porous matrix of Example 1 was affixed to the first adaptor using an O-ring gasket. The 10 ml of produced water was filtered through the nonwoven fibrous porous matrix in a dropwise manner, which took about one minute. Advantageously, the turbid produced water sample passed from the small diameter of the luer lock portion of the syringe adaptor to the larger diameter of the threaded portion of the syringe holder and the filter holder without generating back pressure sufficient to require applying increasing pressure on the syringe plunger (rather than the constant pressure that was applied). The filtrate was discarded. To ensure that all of the produced water sample passed through the disk, a syringe was filled with 5 ml of air, connected to the syringe adaptor, then the air was pushed through the nonwoven fibrous porous matrix. Next, the syringe holder was removed from the filter holder by unthreading the two parts from each other, thereby providing access to the nonwoven fibrous porous matrix. An ATP Water Test was obtained and the foil seal on the test was punctured and kept on the side. The sample collection stick from the ATP Water Test was used to pick up the nonwoven fibrous porous matrix by making a few circular turns of the stick on the matrix. The sample stick having the nonwoven fibrous porous matrix stuck on its end was inserted into the pre-punctured test and analyzed according to the manufacturer&#39;s instructions on a NG luminometer. The resulting signal in Relative Light Units (RLUs) generated the ‘Filter-no wash’ Example 25 reading. 
     For the ‘Filter-wash’ test (i.e., Example 26), a 10 ml sample of the produced water sample D was filtered through a 14 mm disk of the nonwoven fibrous porous matrix of Example 1 as described above for Example 25. After pushing the 5 ml of air through the disk, a new syringe containing 5 ml of ATP free water was attached to the syringe holder. The filter was washed with the ATP free water and the filtrate was discarded. The filter was removed from the holder using the sample collection stick and analyzed, both as described as above for Example 25. The matrices were tested in duplicate. 
     Produced water sample D was tested using the device but without having any nonwoven fibrous porous matrix in the filter holder, using the ATP Water Test for generating Comparative Example 1 RLU readings. The improvement in ATP signal from captured bacteria over a CLEAN-TRACE test (without concentrating the bacteria in a nonwoven fibrous porous matrix) was calculated using the formula below. Data is shown in Table 15 below. 
       Fold increase in ATP signal over current test=(RLUs from post filtration nonwoven matrix disk/RLUs from the unfiltered sample tested using the CLEAN-TRACE ATP water test). 
     14 mm disks of the nonwoven fibrous porous matrix of Example 1 were tested with produced water sample E (i.e., Comparative Example 2) as described above for Examples 25 and 26. Example 27 was the ‘Filter-no wash’ while Example 28 was the ‘Filter-wash’. Data is shown in Table 15 below. 
     
       
         
           
               
             
               
                 TABLE 15 
               
             
            
               
                   
               
               
                 Bacterial capture efficiency and percent recovery 
               
               
                 of ATP in fibrous porous matrices (of Example 
               
               
                 1) using the filtration device of FIG. 9F. 
               
            
           
           
               
               
               
            
               
                   
                 Average ATP signal in 
                 Fold increase over 
               
               
                 Example # 
                 RLUs 
                 current test 
               
               
                   
               
               
                 Comparative Example 1 
                 202 (12%) 
                 N/A 
               
               
                 Example 25 
                 1311 (24%)  
                 6.5 
               
               
                 Example 26 
                 889 (34%) 
                 4.4 
               
               
                 Comparative Example 2 
                  4 (20%) 
                 N/A 
               
               
                 Example 27 
                  50 (25%) 
                 12.5 
               
               
                 Example 28 
                 15452 
                 3863 
               
               
                   
               
               
                 N = 2, stdev less than 10% unless otherwise noted in parentheses. 
               
            
           
         
       
     
     The variation in tests indicates matrix interference. The improvement in ATP signal after washing indicates the decrease in carryover of inhibitory substances, which allows the ATP assay to be used for accurate rapid monitoring of produced water samples. In the case where washing did not improve the signal indicated that the sample contained fewer sources of microbial ATP and more sources of innate ATP. 
     Examples 29 and 30: Making Thin Nonwoven Fibrous Porous Matrices Containing Calcined Magnesium Silicate 
     Two fiber premixes were prepared by mixing various amounts of Fiber 1, Fiber 4, Fiber 5 and Fiber 6 as shown in Table 16 below. 
     For Example 29, the Fiber 6 was added to 3 liters of cold deionized water in a 4 L blender (available from VWR, Radnor, Pa., under the trade designation “WARING COMMERCIAL HEAVY DUTY BLENDER, MODEL 37BL84”) and blended at medium speed for 30 seconds. All other fibers were added and blended for additional 1 minute at low speed. The mixture was examined for uniform dispersion of the fibers without nits or clumps. The particulate additive, CM-111, was added with an additional liter of deionized water and mixed at low speed for 15 seconds. 
     A nonwoven fibrous porous felt was prepared using a pad maker apparatus (obtained from Williams Apparatus, Watertown, N.Y., under the trade designation “TAPPI”) that had a box measuring about 30 centimeters (12 inches) square and 30 centimeters (12 inches) high with a fine mesh screen at the bottom and a drain valve. On the screen ˜a 14 inch (36 cm)×12 inch (30 cm) piece of a polyethylene spunbond (PET Lutradur 7240 obtained from Fiberweb, Cincinnati, Ohio) was laid as scrim on the screen. The box was filled with tap water up to a height of about 1 centimeter above the screen. The fiber and particle additive mixture was poured into the box and the valve was opened immediately which created a vacuum that pulled the water out of the box. 
     The fibrous nonwoven felt was transferred from the apparatus onto a 20 centimeter square sheet of blotter paper (96-pound white paper, obtained from Anchor Paper, St. Paul, Minn.). The felt was sandwiched between 2 to 4 layers of blotter paper, to blot excess water. The pressed felt of Example 29 was then transferred onto a fresh sheet of blotter paper and placed in an oven (HERATHERM oven series OMS100 obtained from Thermo Fisher Scientific, Waltham, Mass.) set at 125° C. for about 3 hours to remove residual water and to form a nonwoven fibrous porous matrix. The resulting fibrous porous matrix of Example 29 was approximately 0.8 to 0.90 millimeters thick. 
     For Example 30, the fiber mixture was prepared as described for Example 29, except as noted, using the amounts shown in Table 16 below. The pad maker apparatus was filled with additional 4 liters of cold deionized water. No spunbond scrim was used on the screen of the apparatus. The fiber and particle additive mixture was poured into the apparatus while opening the valve and draining the water. The fibrous nonwoven felt was removed from the screen by pressing a ˜14 inch (36 cm)×12 inch (30 cm) piece of a polyethylene spunbond onto the wet felt and lifting the scrim. The resulting dried nonwoven fibrous porous matrix was approximately 0.8 to 0.90 millimeters thick. 
                                     TABLE 16                       Material (grams)   Example 29   Example 30                                                        Fiber 1   6.02   6.02           Fiber 4   1.07   1.06           Fiber 5   1.30   1.32           Fiber 6   1.05   2.05           CM-111   4.03   4.08           Basis Weights   126.05   122.17           in g/m 2                          
Testing of Nonwoven Fibrous Porous Matrices with Metal Silicate for Bacterial Capture of  E. coli  
 
     A single colony from a streak culture of  E. coli  (ATCC 11229, a Gram negative organism) was inoculated into 10 ml of TSB (Tryptic Soy Broth, 3% by weight from Difco) incubated overnight for about 20 hours at 37 degrees C. The resulting bacterial stock contained about 1×10 9  cfus/ml. That stock was serially diluted in deionized water to make working stocks of 10 cfus/ml, 1×10 2  cfus/ml, and 1×10 3  cfus/ml. 
     Example 31 
     14 mm disks of the nonwoven fibrous porous matrix of Example 29 were die punched and inserted into 13 mm filter holders (SWINNEX holders obtained from Millipore). 10 ml of 10 cfus/ml working stock was filtered through each disk using a 10 cc syringe. After filtration the disks were discarded. The filtrate was collected in sterile 15 ml polypropylene tubes. A one ml volume of the filtrate was plated on PAC plates. 
     Example 32 
     14 mm disks of the nonwoven fibrous porous matrix of Example 29 were die punched and inserted into 13 mm filter holders (SWINNEX holders obtained from Millipore) and tested for  E. coli  capture using 10 ml of 1×10 2  cfus/ml working stock according to the same procedure as Example 31. 
     Example 33 
     14 mm disks of the nonwoven fibrous porous matrix of Example 29 were die punched and inserted into 13 mm filter holders (SWINNEX holders obtained from Millipore) and tested for  E. coli  capture using 10 ml of 1×10 3  cfus/ml working stock according to the same procedure as Example 31. 
     Examples 34 to 36 
     14 mm disks of the nonwoven fibrous porous matrix of Example 30 were tested according to the same procedures as Examples 31, 32, and 33, to generate Examples 34, 35 and 36, respectively. 
     The  E. coli  stock solutions were also plated on PAC. These were the “100% control” samples. Plate counts were measured per the manufacturer&#39;s instructions using a PETRIFILM Plate Reader. Capture efficiency was calculated using the formulas below. The results are shown in Table 17. 
       % Control=(CFUs in plated filtrates)×100/CFUs in 100% Control
 
       % Capture Efficiency=100−% Control
 
                     TABLE 17                  Capture of  E. coli                                               Ex-   Ex-   Ex-   Ex-   Ex-   Ex-           ample   ample   ample   ample   ample   ample       Sample   31   32   33   34   35   36               % Capture   70.7    53.4   67.1    78.8    71.3   82.8       Efficiency   (48)     (11)     (13)     (26)                 n = 3, % std deviation &lt; 10% unless indicated in parenthesis. The plated 100% control had total 205 cfus/ml (24% stdev), 1895 cfus and 18450 cfus.            
Testing of Nonwoven Fibrous Porous Matrices with Metal Silicate for Bacterial Capture of  S. aureus  
 
     A single colony from a streak culture of  S. aureus  (ATCC 6538, a Gram positive organism) was inoculated into 10 ml of TSB (Tryptic Soy Broth, 3% by weight from Difco) incubated overnight for about 20 hours at 37 degrees C. The resulting bacterial stock contained about 1×10 9  cfus/ml. That stock was serially diluted in deionized water to make working stocks of 10 cfus/ml, 1×10 2  cfus/ml, and 1×10 3  cfus/ml. 
     Example 37 
     14 mm disks of the nonwoven fibrous porous matrix of Example 29 were die punched and inserted into 13 mm filter holders (SWINNEX holders obtained from Millipore). 10 ml of 10 cfus/ml working stock was filtered through each disk using a 10 cc syringe. After filtration the disks were discarded. The filtrate was collected in sterile 15 ml polypropylene tubes. A one ml volume of the filtrate was plated on PAC plates. 
     Example 38 
     14 mm disks of the nonwoven fibrous porous matrix of Example 29 were die punched and inserted into 13 mm filter holders (Swinnex holders obtained from Millipore) and tested for  S. aureus  capture using 10 ml of 1×10 2  cfus/ml working stock according to the same procedure as Example 37. 
     Example 39 
     14 mm disks of the nonwoven fibrous porous matrix of Example 29 were die punched and inserted into 13 mm filter holders (Swinnex holders obtained from Millipore) and tested for  S. aureus  capture using 10 ml of 1×10 3  cfus/ml working stock according to the same procedure as Example 37. 
     Examples 40 to 42 
     14 mm disks of the nonwoven fibrous porous matrix of Example 30 were tested according to the same procedures as Examples 37, 38, and 39, to generate Examples 40, 41, and 42, respectively. 
     The  S. aureus  stock solution was also plated on PAC. These were the “100% control” samples. Plate counts were measured per the manufacturer&#39;s instructions using a PETRIFILM Plate Reader. Capture efficiency was calculated using the formulas below. The results are shown in Table 18. 
       % Control=(CFUs in plated filtrates)×100/CFUs in 100% Control
 
       % Capture Efficiency=100−% Control
 
     
       
         
           
               
             
               
                 TABLE 18 
               
             
            
               
                   
               
               
                 Capture of  S. aureus   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                 Ex- 
                 Ex- 
                 Ex- 
                 Ex- 
                 Ex- 
                 Ex- 
               
               
                   
                   
                 ample 
                 ample 
                 ample 
                 ample 
                 ample 
                 ample 
               
               
                   
                 Sample 
                 37 
                 38 
                 39 
                 40 
                 41 
                 42 
               
               
                   
                   
               
               
                   
                 % Capture 
                 96.6 
                 95.2 
                 96.5 
                 98.3 
                 95.7 
                 96.5 
               
               
                   
                 Efficiency 
               
               
                   
                   
               
               
                   
                 n = 3, % std deviation &lt; 10 % unless indicated in parentheses. The plated 100% control had total 195 cfus/ml (40% stdev), 1380 cfus (12% stdev) and 15950 cfus. 
               
            
           
         
       
     
     While the specification has described in detail certain exemplary embodiments, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily conceive of alterations to, variations of, and equivalents to these embodiments. Furthermore, all publications and patents referenced herein are incorporated by reference in their entirety to the same extent as if each individual publication or patent was specifically and individually indicated to be incorporated by reference. Various exemplary embodiments have been described. These and other embodiments are within the scope of the following claims.