bluuebunny/crossref_metadata_2025 huggingface dataset:
Restriction endonuclease analysis of DNA from Chlamydia trachomatis biovars
Authors: Peterson E M , de la Maza L M
Published: January 2020

DNA from a total of 60 Chlamydia trachomatis isolates was examined by restriction endonuclease analysis. Strains from all established biovars and serovars were tested. There was great diversity between the mouse biovar and the lymphogranuloma venereum (LGV) and trachoma biovars. The LGV and trachoma biovar isolates generated similar fragment patterns; however, distinct fragments appeared to be unique to both biovars, thus allowing differentiation of these two major groups. In most cases, strains of the same serovar could be differentiated from one another when a battery of restriction enzymes was used. In addition, in some cases, certain restriction fragments appeared to be characteristic of strains from a particular geographical location. The DNA patterns generated by all C. trachomatis isolates differed greatly from the DNA patterns generated from the Chlamydia psittaci isolates tested, including TWAR, a human C. psittaci strain.
Passive hemagglutination test for measles immunity and serodiagnosis
Authors: Sakata H , Sugiura A
Published: January 2020

A passive hemagglutination (PHA) test for measles was evaluated in comparison with hemagglutination inhibition (HI) and neutralization (NT) tests. The PHA test determines exclusively the level of antibody directed to the hemagglutinin protein of measles virus. The ratio of PHA to HI titer was 1 to 32 (geometric mean, 6.5) for the first 5 weeks of infection but declined to near unity thereafter. It gradually increased again to 4 to 32 (geometric mean, 11.7) over several years. The initial high PHA titer relative to the HI titer was most likely due to the presence of the immunoglobulin M antibody known to be efficient in agglutination, because 2-mercaptoethanol (2ME) treatment of sera reduced the PHA titer to a level similar to that of the HI titer. The PHA titer in sera obtained after the convalescent phase was insensitive to 2ME, and the relative increase in the PHA over the HI titer was presumably a result of increased antibody avidity. In some individuals, the HI titer fell to below detectable levels several years after either natural infection or vaccination, but the PHA as well as the NT titer remained positive. The PHA titer was therefore a more reliable and more sensitive indicator of immune status against measles than the HI titer. The decrease in PHA titer by 2ME treatment provided evidence of a current or very recent infection. PHA was found to be useful both for assessing immunity status and for serodiagnosis.
Comparison of Western blot (immunoblot) and glycoprotein G-specific immunodot enzyme assay for detecting antibodies to herpes simplex virus types 1 and 2 in human sera
Authors: Ashley R L , Militoni J , Lee F , Nahmias A , Corey L
Published: January 2020

Sera from patients with culture-proven genital herpes infections were tested for herpes simplex virus type 1 (HSV-1)- and HSV-2-specific antibodies by both a Western blot (immunoblot) technique (WBA) and immunodot enzyme assays (IEAs) specific for HSV-1 or HSV-2 glycoprotein G (gG). Of 137 serum samples tested, none was mistyped by either WBA or IEA. Both tests were most sensitive with sera obtained at least 21 days after onset of primary HSV-2 infections or sera drawn during recurrent HSV-2 genital episodes: 75 of 76 (99%) such serum samples were positive for HSV-2 antibody by WBA and 73 of 76 (96%) were positive by IEA. Of sera drawn earlier than 21 days from onset of primary genital HSV-2, antibodies to HSV-2 were detected in 25% by WBA and 8% by IEA. In patients with culture-proven primary genital HSV-1 infection, WBA detected antibodies to HSV-1 proteins in 16 of 17 (94%) serum samples drawn at least 21 days after onset of primary genital HSV-1 infection, compared with 9 of 17 (53%) serum samples tested for gG-1 by IEA. Both WBA and IEA are accurate and sensitive tests for HSV-2 antibody in patients convalescing from a first episode or having symptomatic or asymptomatic recurrent genital herpes. WBA was more sensitive than IEA in detecting seroconversion following primary HSV-1 genital herpes, although both assays may miss persons undergoing early seroconversion to HSV-2.
Evaluation of the Rapid Mastitis Test for identification of Staphylococcus aureus and Streptococcus agalactiae isolated from bovine mammary glands
Authors: Watts J L , Owens W E
Published: January 2020

A latex agglutination test system (Rapid Mastitis Test [RMT]; Immucell, Portland, Maine) containing reagents for the identification of Staphylococcus aureus and Streptococcus agalactiae from bovine intramammary infections was evaluated with 527 staphylococcal and 267 streptococcal isolates. The RMT Staphylococcus aureus reagent detected 94.2% of 242 Staphylococcus aureus isolates, 80% of 25 Staphylococcus intermedius isolates, and 42.8% of 21 tube coagulase-positive Staphylococcus hyicus isolates. All Streptococcus agalactiae isolates were correctly identified by the RMT Streptococcus agalactiae reagent. Cross-reactions were observed with one Streptococcus dysgalactiae and three Streptococcus uberis strains. The RMT was found to be an acceptable method for the detection of Staphylococcus aureus and Streptococcus agalactiae isolated from bovine mammary glands. The occurrence of coagulase-positive staphylococci other than Staphylococcus aureus requires biochemical testing for species level identification.
Application of optical properties of the Vi capsular polysaccharide for quantitation of the Vi antigen in vaccines for typhoid fever
Authors: Stone A L , Szu S C
Published: January 2020

The capsular polysaccharide of Salmonella typhi and of Citrobacter freundii (Vi) is a linear homopolymer of alpha 1,4-linked N-acetylgalactosaminuronic acid, variably O-acetylated at the C-3 position. Vaccines composed of Vi confer protection against typhoid fever with an efficacy of about 70%; Vi has recently been conjugated to proteins to increase its immunogenicity and effectiveness (I.L. Acharya, R. Tapa, V.L. Gurubacharya, M.B. Shrestha, C.U. Lowe, D.D. Bryla, R. Schneerson, J.B. Robbins, T. Crampton, B. Trollfors, M. Cadoz, D. Schulz, and J. Armand, N. Engl. J. Med. 317:1101-1104, 1987; K.P. Klugman, I. Gilbertson, H.J. Kornhof, J.B. Robbins, R. Schneerson, D. Schulz, M. Cadoz, and J. Armand, Lancet ii:1165-1169, 1987; S.C. Szu, A.L. Stone, J.D. Robbins, R. Schneerson, and J.B. Robbins, J. Exp. Med. 166:1510-1524, 1987). Vi, however, cannot be measured by conventional colorimetric methods. Two optical techniques were adapted to quantitate Vi in vaccines. The first, Fourier-transformed infrared spectroscopy, was performed on salt-free, freeze-dried samples. The intensities of the absorbance peaks of Vi were proportional to the amount of Vi within the range of 0.25 to 2.0 mg. The amount of Vi was determined from integrated absorptions at the 1,235- or 1,417-cm-1 band. The second technique, spectrophotometric titration, was more sensitive than the Fourier-transformed infrared spectroscopy and could be performed on dilute solutions. The metachromatic effect of the reaction between the aromatic cationic dye acridine orange and the carboxyl groups of Vi was quantitative within +/- 2% in the range of 20 to 700 micrograms of Vi per ml. The accuracy of the titration of Vi in the vaccines was within +/- 8%. These two methods may be applicable to measure other capsular polysaccharides in vaccines.
Comparison of three techniques for detection of Chlamydia trachomatis in endocervical specimens from asymptomatic women
Authors: Lefebvre J , Laperrière H , Rousseau H , Massé R
Published: January 2020

Culture in DEAE-dextran-treated HeLa 229 cells, a solid-phase enzyme immunoassay (EIA) (Chlamydiazyme; Abbott Laboratories, North Chicago, Ill.), and a direct immunofluorescence test (DFA) (MicroTrak; Syva Co., Palo Alto, Calif.) were compared for the detection of Chlamydia trachomatis in endocervical specimens from 715 asymptomatic women. Response to antibiotic therapy was also monitored at least 4 weeks after completion of therapy. An additional sample was collected at a control visit, and a second culture was performed if discrepancies were observed between the three tests. A total of 48 infections were diagnosed, for a prevalence of 6.7%. At the first visit, 37 specimens were positive by culture. The respective sensitivities of EIA and DFA were 78.4 and 81.1% and the respective specificities were 96.8 and 97.9% when compared with the cell culture technique. The positive predictive values were 56.9 and 68.2%, respectively. When the additional 11 infections detected by the second culture were included to establish a new standard of positivity, the sensitivity of the first culture was estimated at 77.1%. The positive predictive values of EIA and DFA increased to 77.6 and 83.7%, respectively. EIA and DFA performed as well as culture for control of therapy; a 100% agreement among the three techniques was observed.
Quality of powdered substitutes for breast milk with regard to members of the family Enterobacteriaceae
Authors: Muytjens H L , Roelofs-Willemse H , Jaspar G H
Published: January 2020

Members of the family Enterobacteriaceae were cultured from 52.5% of 141 milk substitute infant formulas which were obtained in 35 countries. The concentration did not exceed a level of 1 CFU/g in any product. The species which were isolated most frequently were Enterobacter agglomerans, cloacae, Enterobacter sakazakii, and Klebsiella pneumoniae. If infections due to these organisms occur, it can be useful to include a check of the hygienic precautions which are taken during the preparation and storage of the formula. Milk powders without members of the Enterobacteriaceae might offer extra protection to the newborn if some multiplication does occur in the formula.
Bacteremia caused by Mycobacterium neoaurum
Authors: Davison M B , McCormack J G , Blacklock Z M , Dawson D J , Tilse M H , Crimmins F B
Published: January 2020

An immunocompromised patient with an indwelling Hickman catheter developed Mycobacterium neoaurum bacteremia. This rapidly growing mycobacterium was previously isolated from soil, dust, and water but has not been described as a human pathogen. The infection responded to therapy with cefoxitin and gentamicin. It was not necessary to remove the Hickman catheter.
Dot immunobinding assay compared with enzyme-linked immunosorbent assay for rapid and specific detection of retrovirus antibody induced by human or simian acquired immunodeficiency syndrome
Authors: Heberling R L , Kalter S S , Marx P A , Lowry J K , Rodriguez A R
Published: January 2020

A rapid, specific, and sensitive modification of the dot immunobinding assay was compared with the standard enzyme immunoassay as a screening procedure for the detection of antibody in human or simian acquired immunodeficiency syndrome. Comparative testing with the available enzyme immunoassay procedures, either in commercial kit form or as provided by diagnostic laboratories, indicated excellent correlation. Ease of operation and cost are key features of the dot immunobinding assay procedure.
Comparison of polyclonal rabbit antisera with monoclonal antibodies for serological typing of Pseudomonas aeruginosa
Authors: Strickland M A , Gaston M A , Pitt T L
Published: January 2020

A panel of 219 distinct strains of Pseudomonas aeruginosa were serotyped with a set of monoclonal antibodies prepared against the serotype strains of the Homma scheme (J. Y. Homma, Jpn. J. Exp. Med. 46:329-336, 1976). A total of 87.6% were typable, and there was very good agreement with the corresponding polyclonal serotype. A high proportion of strains that were polyagglutinating or nontypable with polyclonal antisera were agglutinated by antibody towards Homma group M.
Evaluation of in vitro methods for testing ceftriaxone against anaerobic bacteria, including quality control guidelines
Authors: Barry A L , Jones R N
Published: January 2020

Tests with 100 anaerobic bacterial isolates demonstrated comparability between ceftriaxone MICs obtained with the reference agar dilution procedure and those obtained with a broth microdilution susceptibility testing procedure. The aerobically incubated thioglycolate disk elution test was also evaluated. Six 30-micrograms ceftriaxone disks in 5 ml of thioglycolate separated strains for which MICs were less than or equal to 32 micrograms/ml from those for which MICs were greater than or equal to 64 micrograms/ml (6% overall discrepancies). Quality control limits for ceftriaxone agar dilution tests were determined to be as follows: Bacteroides fragilis ATCC 25285, 32 to 128 micrograms/ml; and Bacteroides thetaiotaomicron ATCC 29741, 64 to 256 micrograms/ml.
Enterobacter agglomerans lipopolysaccharide-induced changes in pulmonary surfactant as a factor in the pathogenesis of byssinosis
Authors: DeLucca A J , Brogden K A , Engen R
Published: January 2020

Lipopolysaccharide (LPS) from Enterobacter agglomerans and pulmonary surfactant mixtures were centrifuged in discontinuous sucrose gradients to determine whether LPS bound to surfactant and examined in a Langmuir trough with a Wilhelmy balance to determine whether LPS altered the surface activity of surfactant. The LPS was found to bind to the surfactant and altered its surface tension properties. The binding of LPS to surfactant in the lung may change the physiological properties of surfactant and be a possible mechanism for the pathogenesis of byssinosis.
Recurrent epidermal cyst infection caused by Brucella melitensis in a diabetic patient
Authors: Dhar R , Dhar P M , Gafoor M
Published: January 2020

A presternal swelling diagnosed clinically as a sebaceous cyst in a 60-year-old diabetic patient was surgically drained, and the aspirated purulant material yielded growth of Brucella melitensis. The swelling recurred four times and was drained on every occasion. The patient responded to surgical excision and antibrucella treatment. The histologic diagnosis was an epidermal cyst.
Urease-positive thermophilic Campylobacter (Campylobacter laridis variant) isolated from an appendix and from human feces
Authors: Mégraud F , Chevrier D , Desplaces N , Sedallian A , Guesdon J L
Published: January 2020

Urease-positive thermophilic campylobacters were isolated for the first time from the feces of two adults with diarrheal disease and from the appendix of a child with appendicitis. They were identified as Campylobacter laridis by a hybridization dot blot assay. Urease testing should be included in the tests used for the identification of campylobacters at the species level, even for those strains which are not of gastric origin.
Detection of coagulase activity in Erysipelothrix rhusiopathiae
Authors: Tesh M J , Wood R L
Published: January 2020

Coagulase activity was detected in 99% of 225 strains of Erysipelothrix rhusiopathiae. These strains included isolates from a variety of animal and environmental sources. Activity could be detected by the tube or slide technique, with the tube reactions being easier to interpret. Coagulation of rabbit and/or bovine plasma was observed, with most strains reacting in both. The activity appeared to be a common characteristic of the species and may be useful in differentiating E. rhusiopathiae from Listeria and Corynebacterium species, which fail to demonstrate the activity. There was no correlation noted between coagulase activity and the serotype, source, geographic origin, or virulence (as detected by mouse pathogenicity tests) of the isolates.
Sera from patients with high titers of antibody to streptolysin O react with listeriolysin
Authors: Chatzipanagiotou S , Hof H
Published: January 2020

Sera of patients with suspected rheumatic fever and elevated titers of antibody to streptolysin O were examined by an immunoblotting technique. All but two serum samples, which yielded relatively low titers, bound to a 60-kilodalton protein in the supernatant from a culture of Listeria monocytogenes, which presumably represents the listeriolysin.
Isolation of an unidentified pink-pigmented bacterium in a clinical specimen
Authors: Odugbemi T , Nwofor C , Joiner K T
Published: January 2020

An unidentified pink-pigmented bacterium isolated from a clinical specimen is reported. The organism was oxidase, urease, and catalase positive; it grew on Thayer-Martin and MacConkey media. The isolate is possibly similar to an unnamed taxon (G.L. Gilardi and Y.C. Faur, J. Clin. Microbiol. 20:626-629, 1984); however, it had unique characteristics of nonmotility with no flagellum detectable and was a gram-negative coccoid with a few rods in pairs and negative for starch hydrolysis.
Multilocus enzyme analysis of Legionella dumoffii
Authors: Woods T C , McKinney R M , Plikaytis B D , Steigerwalt A G , Bibb W F , Brenner D J
Published: January 2020

Variability among 29 clinical and environmental strains of Legionella dumoffii was investigated by multilocus enzyme analysis by use of starch gel electrophoresis. Based on results of analysis at 20 enzyme loci, the strains were separated into five closely related electrophoretic types (ETs), which were clearly distinguished from 53 strains representing 53 ETs of L. pneumophila. DNA hybridization results (hydroxyapatite method, 60 and 75 degrees C) for representative strains confirmed that all L. dumoffii ETs were a single genetic species. Although multilocus enzyme analysis indicated that L. dumoffii was genetically a quite uniform species, sufficient variability existed to warrant electromorph fingerprinting for epidemiologic studies.
Enzyme-linked immunosorbent assay for immunoglobulin G subclass antibodies specific for enterobacterial Re core glycolipid in healthy individuals and in patients infected by gram-negative bacteria
Authors: Nys M , Joassin L , Somzee A , Demonty J
Published: January 2020

An enzyme-linked immunosorbent assay was developed to study the subclass distribution of immunoglobulin G (IgG) specific to the core glycolipid (CGL) of the Re mutant of Salmonella minnesota R595 in serum samples from individuals with an IgG response toward these antigens. In a group of healthy blood donors, we detected predominantly the IgG2 and IgG1 subclasses. In a group of patients in an intensive care unit who developed infectious complications due to gram-negative bacteria, the anti-CGL IgG activity was due mainly to the IgG2 and IgG3 subclasses. In all serum samples found to be IgG positive, the assay for anti-CGL IgG2 was positive. This subclass was revealed to play a predominant role in patients displaying a seroconversion or a significant rise in their antibody response toward CGL. IgG4 was found or appeared only in patients with confirmed bacteremia. In addition, we observed a drop in anti-CGL IgG2 before the death of patients undergoing a septic shock or an irreversible organ failure, suggesting that the anti-CGL IgG2 activity could be used as a marker of the evolution of the illness in this group of patients.
New semisolid agar for the detection of motile salmonellae
Authors: Hine E A , Stefen E K , Wagner J E
Published: January 2020

A semisolid selective motility agar based on selenite broth and designated semisolid selenite fecal (SSF) agar was developed for recovery of motile salmonellae from large numbers of rodent fecal specimens. The medium is easily prepared and inoculated; results are readily interpreted. When combined with selenite or gram-negative broth enrichment, SSF agar yielded significantly better Salmonella isolation from experimentally infected rodents than a standard battery of media. Only 14 non-Salmonella isolates from 1,002 Salmonella-free rodent fecal specimens migrated on SSF agar.
Reaction of Bacillus subtilis products with amebocyte lysates of the Japanese horseshoe crab, Tachypleus tridentatus
Authors: Hodes D S , Bottone E J , Hass A , Hodes H L
Published: January 2020

Autoclaved aqueous extracts of Candida albicans cells (and the glucans isolated from them) give a positive reaction with a chromogenic substrate combined with amebocyte lysates of the Japanese horseshoe crab, Tachypleus tridentatus (CS-TAL). The extracts and glucans activate the lysate enzyme compound G, which in turn activates clotting enzyme. Activated clotting enzyme causes a positive CS-TAL reaction. C. albicans extracts and glucans react positively with a commercially available, unaltered CS-TAL preparation (Toxicolor), but they give a negative reaction with a CS-TAL from which compound G has been excluded (Endospecy). An autoclaved, sterile preparation of Sabouraud glucose broth used as a control in one experiment gave (like Candida extracts) a positive reaction with Toxicolor and a negative reaction with Endospecy. We found that the peptone powder used to make the Sabouraud glucose broth was contaminated with a strain of Bacillus subtilis. Autoclaved aqueous extracts of culture-grown B. subtilis cells were positive with Toxicolor and negative with Endospecy. This was also the case with two other strains of B. subtilis. Polysaccharides obtained from these extracts gave the same result. Endotoxin activates clotting enzyme through activation of the lysate enzyme compound C, which is present in both Toxicolor and Endospecy. Endotoxin, therefore, reacts with both CS-TAL preparations. Simultaneous assay with Toxicolor and Endospecy distinguishes endotoxin from fungal products, but since products of fungi and B. subtilis both give a positive Toxicolor and a negative Endospecy test, a simultaneous assay cannot differentiate them. However, this does not decrease the clinical value of the simultaneous Toxicolor-Endospecy assay for distinguishing fungal infection from endotoxemia because B. subtilis so rarely causes disease that it can be excluded from clinical consideration.
Antigen(s) responsible for immunoglobulin G responses specific for the acute stage of Toxoplasma infection in humans
Authors: Suzuki Y , Thulliez P , Desmonts G , Remington J S
Published: January 2020

An agglutination test for immunoglobulin G (IgG) Toxoplasma antibodies with acetone-fixed tachyzoites (AC antigens; AC agglutination test) was positive only with sera from patients during the acute stage of their infection. In contrast, when the test was performed with Formalin-fixed tachyzoites (HS antigens; HS agglutination test), positive results were obtained during both the acute and chronic (latent) stages of the infection. Studies were performed to define the antigen(s) of T. gondii which are detected by IgG antibodies present only during the acute stage of the infection. Sera of mice immunized with AC antigens recognized predominantly 10 antigens of tachyzoites by immunoblot analysis. Sera from individuals with the acute but not chronic infection reacted strongly with these same 10 antigens in immunoblots. Sera of mice immunized with HS antigens recognized more Toxoplasma antigens on immunoblots than did mouse AC antibodies. Absorption of the latter with HS antigens removed detectable reactivity of AC antibodies in immunoblots and in the AC and HS agglutination tests, suggesting that AC antigens are a selected portion of HS antigens. AC antigens were specific for tachyzoites in that AC antibodies reacted with the cell membranes of both forms of the organism in an indirect fluorescent-antibody test. Tachyzoite-specific antigen(s) appear to be useful in differentiating between the acute and chronic stages of Toxoplasma infection through their detection by IgG antibodies.
Evaluation of substrates for radiometric detection of bacteria in blood cultures
Authors: Bopp H , Ellner P D
Published: January 2020

Various 14C-labeled substrates were evaluated for their potential use in blood culture media. These uniformly labeled compounds were added to hypertonic and anaerobic formulations of modified Columbia broth and compared with analogous BACTEC media with the BACTEC 460. Different bacterial species gave significant growth indices when 2.0 microCi of labeled glucose, glutamic acid, aspartic acid, arginine, or formate was used alone or in combinations in the experimental media. The combination of glucose, glutamic acid, and sodium formate was selected, and simulated blood cultures with representative aerobic, facultative, and anaerobic bacteria and a yeast were compared with BACTEC vials. Under these conditions, the experimental media often became positive several hours earlier than the BACTEC vials and usually produced higher growth indices.
Characterization of antibodies to sporozoites in Plasmodium falciparum malaria and correlation with protection
Authors: Webster H K , Brown A E , Chuenchitra C , Permpanich B , Pipithkul J
Published: January 2020

The antibody response to sporozoites of Plasmodium falciparum and the role of these antibodies in protection against malaria have not been systematically investigated. An understanding of antisporozoite antibodies in natural infection is, however, important to the development of a human malaria vaccine. In a prospective study in Thailand, an antibody response to sporozoites was observed only in individuals who developed parasitemia. Antibodies were detected against an epitope in the repeat region of the circumsporozoite (CS) protein. Current candidate sporozoite vaccines are based on CS repeat antigens. The CS antibody response was of low magnitude, peaked after detection of parasitemia, and had a serum half-life of less than 1 month. CS antibody boosting occurred in only 6% of reinfected individuals. These observations suggest that antisporozoite antibody is poorly developed under natural conditions and appears not to protect against development of malaria.
Detection of herpes simplex virus DNA from genital lesions by in situ hybridization
Authors: Langenberg A , Smith D , Brakel C L , Pollice M , Remington M , Winter C , Dunne A , Corey L
Published: January 2020

Lesion specimens from 118 episodes of recurrent genital herpes were used to compare herpes simplex virus (HSV) isolation with a direct specimen test for in situ DNA hybridization utilizing a biotinylated probe. The frequency of detection of HSV was similar with both tests; HSV was isolated from 81% of vesicular lesions, 76% of pustules, and 67% of ulcers, while HSV DNA was detected in 77, 76, and 55% of lesions in these stages, respectively. Utilizing both methods, HSV was identified in 91, 94, and 79%, respectively. The sensitivity and specificity of the DNA probe in comparison to standard viral isolation in tissue culture were 92 and 63%, respectively. Seven DNA-positive, viral isolation-negative specimens were obtained from patients who had positive culture confirmation at some time subsequent or prior to enrollment, suggesting that these were true positive results. The sensitivity of the DNA probe was dependent on cellular content of the specimen, and 36 (28%) of the 127 submitted specimens had fewer than 20 nonsuperficial cells. The DNA probe was rapid and convenient; its major disadvantage was the lack of type-specific information. The performance of the probe in lower-prevalence populations and in asymptomatic shedding of HSV remains to be evaluated.
Solid-phase immune electron microscopy with human immunoglobulin M for serotyping of Norwalk-like viruses
Authors: Lewis D C , Lightfoot N F , Pether J V
Published: January 2020

A solid-phase immune electron microscopy method that uses protein A, goat anti-human immunoglobulin M (IgM), and human serum is described. Evaluation of the method with different immunoglobulin fractions showed that human IgM constituted the major virus capture antibody. The method appeared to distinguish between two Norwalk-like virus serotypes and demonstrated specific IgM responses to these serotypes in infected individuals. Further work is being carried out to define the relationship of these two serotypes to the previously described Norwalk agent (A. Z. Kapikian, R. G. Wyatt, R. Dolin, T. S. Thornhill, A. R. Kalica, and R. M. Chanock, J. Virol. 10:1075-1081, 1972), and four subsequent hospital outbreaks are being studied.
Quantitation of serotype-specific and cross-reacting group-specific antigens by coagglutination and immunodiffusion tests for differentiating Actinobacillus (Haemophilus) pleuropneumoniae strains belonging to cross-reacting serotypes 3, 6, and 8
Authors: Mittal K R , Higgins R , Lariviere S
Published: January 2020

There are strong cross-reactions among strains of Actinobacillus pleuropneumoniae belonging to serotypes 3, 6, and 8. Various serological tests were used to differentiate these serotypes from each other. Tube agglutination, coagglutination, and indirect hemagglutination tests were not sufficiently sensitive to differentiate strains of serotypes 3, 6, and 8. However, higher antibody titers were obtained with a 2-mercaptoethanol agglutination test in homologous rabbit antisera. Absorption of immune sera with homologous and heterologous serotypes as well as quantitative estimation of antigenic activity in the unheated and heat-treated bacterial cell suspensions of reference strains with rabbit homologous and heterologous antisera revealed serotype-specific and cross-reacting group-specific antigens. Usually, serotype-specific antigens were major and dominant over group-specific antigens. The coagglutination test could be used quantitatively to measure the ratio of serotype-specific and group-specific antigens with rabbit hyperimmune sera against serotypes 3, 6, and 8. The highest antigen content for a particular serotype reflected serotype-specific antigen. For strains showing equal amounts of antigen for two or more serotypes in the coagglutination test, the immunodiffusion test with boiled cell-saline extract as the antigen and rabbit antisera against whole-cell suspensions of serotypes 3, 6, and 8 clearly revealed the serotype-specific antigen. It is suggested that coagglutination and immunodiffusion tests could be used successfully to determine the exact serotype of strains belonging to serotypes 3, 6, and 8.
Evaluation of rubella immune status by three commercial enzyme-linked immunosorbent assays
Authors: Field P R , Ho D W , Cunningham A L
Published: January 2020

Three commercial indirect enzyme-linked immunosorbent assays (ELISAs) (Enzygnost-Rubella, RUBELISA, and ORTHO Rubella) were evaluated for the determination of immune status by testing 1,090 serum specimens, 410 of which were from nonimmune patients. In comparison with the standard reference technique, the hemagglutination inhibition (HAI) test, the sensitivities of ORTHO Rubella (100%) and Enzygnost-Rubella (99.26%) were excellent, whereas the sensitivity of RUBELISA (95.60%) was marginally lower because of the inability of this assay to detect antibody in 22% of the serum specimens with HAI titers of 10 and 11% of sera with HAI titers of 20. The specificity of all three systems was greater than 97%. There was a linear correlation between mean ELISA values and increasing HAI titers (r greater than or equal to 0.94). Both ORTHO Rubella and Enzygnost-Rubella were shown to be suitable replacements for the HAI test, provided that an equivocal zone is incorporated in the ORTHO system and only unheated sera are used in the Enzygnost system.
Comparison of two GM1-erythrocyte assays to detect heat-labile Escherichia coli enterotoxin in stool specimens
Authors: Germani Y , Guesdon J L , Phalente L , Begaud E , Moreau J P
Published: January 2020

Two erythrocyte immunoassay techniques to detect the presence of Escherichia coli heat-labile enterotoxin (LTh) in stool supernatants and cell-free culture supernatants were compared. In the competitive assay, GM1 ganglioside was coated onto V-shaped-well microdilution plates and enterotoxin was coupled to sheep erythrocytes. As little as 0.8 ng of LTh per ml was detected by this method, which was based on the competition between the LTh of the test sample and the sensitized erythrocytes. The second assay made use of chimera antibody prepared by coupling polyclonal anti-LTh antibody to a monoclonal antibody specific for sheep erythrocytes. In this case, LTh, which was specifically bound to a GM1 ganglioside-coated plate, was detected by successively adding the chimera antibody and sheep erythrocytes. The limit of detection of the chimera antibody erythrocyte immunoassay was 0.2 ng/ml. Stool samples were collected from 167 infants hospitalized for diarrhea in the hospital of Noumea, New Caledonia. False-negative reactions due to proteases present in the stool samples were avoided by the addition of phenylmethylsulfonyl fluoride.
Brucella abortus 1119-3 O-chain polysaccharide to differentiate sera from B. abortus S-19-vaccinated and field-strain-infected cattle by agar gel immunodiffusion
Authors: Cherwonogrodzky J W , Nielsen K H
Published: January 2020

Purified Brucella abortus 1119-3 and Brucella melitensis 16M lipopolysaccharide O-chain polysaccharides were not precipitated in agar gel immunodiffusion by any of 24 sera from vaccinated cattle but were precipitated by 18 of 24 sera from infected cattle. This difference can be used to differentiate sera of cattle vaccinated with B. abortus S-19 from sera of some field-strain-infected cattle.
Biophysical optima for metabolism of Mycobacterium leprae
Authors: Franzblau S G , Harris E B
Published: January 2020

The metabolic response of freshly harvested, nude-mouse-derived Mycobacterium leprae to biophysical parameters was studied to facilitate an understanding of axenic culture requirements. Quantitation of intracellular ATP and the rate of [U-14C]palmitic acid incorporation into phenolic glycolipid I (PGL-I) were used as metabolic indicators after axenic incubation in modified Dubos medium under various biophysical conditions. PGL-I synthesis was optimal at 33 degrees C, whereas ATP was optimally maintained at less than or equal to 33 degrees C. Both metabolic indices showed sharp reductions at 37 degrees C. After 5 days of incubation, PGL-I synthesis and ATP maintenance showed pH optima of 5.1 to 5.6, with the higher value appearing optimal for ATP maintenance after extended incubation. Metabolic activity was negatively affected by strong reducing agents, and ATP maintenance was optimal when the gaseous environment was maintained at 2.5 to 10% oxygen. The results may partially explain the failure to cultivate the leprosy bacillus in vitro.
Isolation of Mobiluncus species from clinical specimens by using cold enrichment and selective media
Authors: Smith H J , Moore H B
Published: January 2020

New and selective Rlk and SA media, combined with cold enrichment at 4 to 5 degrees C, allowed isolation of Mobiluncus species from patients with bacterial vaginosis at higher rates than with conventional cultivation methods. Rlk medium consists of Columbia CNA agar supplemented with peptone, yeast extract, 5% laked rabbit or sheep blood, nalidixic acid, and tinidazole. SA medium consists of Columbia CNA agar supplemented with 2% rabbit serum, 1.6% laked rabbit or sheep blood, nalidixic acid, and tinidazole. Use of these selective media plus the cold enrichment technique permitted Mobiluncus species to propagate at rates similar to those of other anaerobic members of the vaginal flora.
Serologic analyses of Peromyscus leucopus, a rodent reservoir for Borrelia burgdorferi, in northeastern United States
Authors: Magnarelli L A , Anderson J F , Hyland K E , Fish D , Mcaninch J B
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) and indirect fluorescent-antibody test were used to detect antibodies to Borrelia burgdorferi, the causative agent of Lyme disease, in Peromyscus leucopus (white-footed mouse). Of the 661 mice captured in Connecticut, Rhode Island, and New York during 1980 and 1983 to 1987, 166 (25.1%) had antibodies to B. burgdorferi by ELISA. Comparative analyses of 210 serum specimens, collected in areas where Lyme disease is endemic, revealed a threefold difference in sensitivity between the ELISA (38.1% positive) and the indirect fluorescent-antibody method (12.4%). Although prevalence of seropositive P. leucopus was highest during June, elevated amounts of antibody (1:1,280 to 1:2,560) were detected in mice that harbored spirochetes during all seasons. Being reservoirs for B. burgdorferi, these rodents are suitable for monitoring spirochete infections at foci and should be included in field evaluations of control programs aimed at suppressing Lyme disease.
Analysis of bronchoalveolar lavage specimens from immunocompromised patients with a protocol applicable in the microbiology laboratory
Authors: Kahn F W , Jones J M
Published: January 2020

Several studies have concluded that bronchoalveolar lavage (BAL) is a useful technique for diagnosing pulmonary disease in immunocompromised patients, but implementation of a protocol for obtaining, processing, and analyzing BAL specimens in a clinical microbiology laboratory has not been reported. We determined the utility of a laboratory protocol by analyzing 100 BAL specimens from 94 immunocompromised patients. Each BAL specimen was cultured quantitatively for bacteria. A concentrate of each specimen was cultured for fungi, viruses, mycobacteria, and Legionella sp. Slides of the BAL concentrate were prepared by cytocentrifugation and stained by a number of histochemical and fluorescence techniques. Overall diagnostic yields of 81% for infections, 90% for hemorrhage, and 13% for neoplasms were obtained with the patients studied. BAL analysis was incapable of diagnosing drug- or radiation-induced pneumonitis or idiopathic interstitial pneumonitis. After evaluation of the protocol was completed, it was successfully implemented in two university-based clinical microbiology laboratories as a routine diagnostic service.
Association of viridans group streptococci from pregnant women with bacterial vaginosis and upper genital tract infection
Authors: Rabe L K , Winterscheid K K , Hillier S L
Published: January 2020

The prevalence and role of viridans group streptococci in the female genital tract have not been well described. In this study of 482 pregnant women, 147 (30%) were culture positive for viridans group streptococci. Of 392 women with predominant Lactobacillus morphotypes by Gram stain (normal), 110 (28%) were colonized with viridans group streptococci, compared with 37 (41%) of 90 women with bacterial vaginosis (BV) (P = 0.02). To determine whether any species were associated with BV, 177 consecutively isolated viridans group streptococci from the vagina were identified to the species level by using the Facklam scheme. The most frequently isolated species from the vagina was Streptococcus intermedius (13%), followed by Streptococcus acidominimus (6%), Streptococcus constellatus (5%), Streptococcus sanguis II (4%), Streptococcus mitis (2%), Streptococcus salivarius (2%), Streptococcus morbillorum (2%), Streptococcus sanguis I (1%), Streptococcus mutans (0.2%), and Streptococcus uberis (0.2%) with an average of 1.2 species per woman. The distribution of the species among women with BV compared with normal women was not significantly different, with the exception of two species which were associated with BV: S. acidominimus (18% versus 3%, P less than 0.001) and S. morbillorum (6% versus 0.7%, P = 0.005). Amniotic fluid and placenta cultures yielded 54 isolates: S. sanguis II (13 isolates), S. acidominimus (9 isolates), S. intermedius (10 isolates), S. constellatus (3 isolates), S. mitis (4 isolates), S. sanguis I (4 isolates), S. morbillorum (5 isolates), S. mutans (2 isolates), S. uberis (1 isolate), mannitol-positive S. intermedius (1 isolate), and 2 isolates which were not classified. The distribution of species isolated from the upper genital tract was not a reflection of the distribution in the lower genital tract. Dextran-producing species of viridans group streptococci may have a greater pathogenic potential in the placenta than the non-dextran-producing species.
Epidemiology of fecal strains of the family Enterobacteriaceae in 22 neonatal wards and influence of antibiotic policy
Authors: Tullus K , Berglund B , Fryklund B , Kühn I , Burman L G
Published: January 2020

The gram-negative fecal floras from 953 infants were studied upon discharge of the infants from 22 neonatal wards. More than 600 distinct phenotypes of Escherichia coli, Klebsiella spp., and Enterobacter spp. were distinguished by high-resolution biotyping. The colonization patterns observed showed considerable local and temporal variation. The major (M) strains (phenotypes), which colonized more than 10% and up to 78% of the infants in a ward (median, 23%), were Klebsiella oxytoca (15 strains), E. coli (4 strains), Klebsiella pneumoniae (1 strain), and Enterobacter cloacae (1 strain). Resistance to beta-lactam antibiotics was more pronounced among M strains than among strains of enteric bacteria colonizing few or single infants only. Local antibiotic policy influenced the colonization patterns. Despite the fact that M strains of Klebsiella spp. were usually resistant to ampicillin as well as to cephalexin and cefuroxime, their local dissemination was associated with the use of ampicillin with or without gentamicin but not with the use of cefuroxime. It thus appeared that in the neonatal setting, ampicillin posed a greater risk of local spread of certain drug-resistant bacterial clones than a newer cephalosporin, such as cefuroxime.
Recovery of anaerobic bacteria from clinical specimens in 12 years at two military hospitals
Authors: Brook I
Published: January 2020

Examination of 15,844 clinical specimens submitted over 12 years (1973 to 1985) to the anaerobic microbiology laboratories in two military hospitals demonstrated the recovery of anaerobic bacteria in 4,458 (28.1%) specimens. The specimens yielded 6,557 anaerobic isolates (1.47 isolates per specimen). Bacteroides spp. accounted for 43% of all isolates; anaerobic gram-positive cocci, 26%; Clostridium spp., 7%; and Fusobacterium spp., 4%. Bacteroides spp. predominated in abscesses, obstetrical and gynecological (OBG) infections, abdominal infections, cysts, wounds, and tumors. Members of the Bacteroides fragilis group accounted for 44% of all Bacteroides spp., and of them, B. fragilis was mostly isolated in abscesses, wounds, abdomen, and blood. Pigmented Bacteroides spp. accounted for 21% of all Bacteroides sp. isolates and were mostly isolated in sinus, eye, chest, bone, and ear infections. Bacteroides melaninogenicus accounted for 42% of this group's isolates. Bacteroides bivius accounted for 9% of Bacteroides spp., and most isolates were found in OBG infections. Anaerobic gram-positive cocci were mostly isolated in OBG infections, abscesses, and wounds. The predominant anaerobic gram-positive cocci were Peptostreptococcus magnus (18%), Peptostreptococcus asaccharolyticus (17%), Peptostreptococcus anaerobius (16%), and Peptostreptococcus prevotii (13%). Clostridium spp. were mostly isolated from wounds, abscesses, abdominal infections, and blood. The predominant strain was Clostridium perfringens (48%). Fusobacterium spp. were recovered in abscesses and abdominal and OBG infections. The predominant isolate was Fusobacterium nucleatum (47%). These data illustrate the relative frequency of the different anaerobic bacteria in a variety of infections and demonstrate the predominance of certain isolates at different sites.
Restaurant-associated outbreak of typhoid fever in Maryland: identification of carrier facilitated by measurement of serum Vi antibodies
Authors: Lin F Y , Becke J M , Groves C , Lim B P , Israel E , Becker E F , Helfrich R M , Swetter D S , Cramton T , Robbins J B
Published: January 2020

Ten cases of typhoid fever occurred between 24 August and 1 September 1986 in the vicinity of Silver Spring, Md. Shrimp salad served in a fast-food restaurant was implicated as the source of infection. Stool cultures were obtained from 104 employees, and serum Vi antibodies were assayed in 97 of the employees. Salmonella typhi was isolated from stool cultures of an 18-year-old asymptomatic female employee, who was a food handler. A high level of Vi antibodies (79.0 micrograms/ml), measured by radioimmunoassay, was found in her serum. She had emigrated from an endemic area at the age of 14 years and had visited that endemic area 2 years previously. The causal relation between the carrier and the 10 cases of typhoid fever was confirmed by a common bacteriophage type, denoted "degraded Vi resembling O," in the S. typhi isolates. This phage type is rare in the western hemisphere but common in the endemic area from which the carrier had emigrated. The high level of Vi antibody in the asymptomatic carrier, in contrast to the lower levels in the convalescent- and postimmunization-phase sera, facilitated the identification of the source infection in this outbreak. This radioimmunoassay offers a rapid and standardized method for identifying carriers of S. typhi.
Recovery of resistant enterococci during vancomycin prophylaxis
Authors: Kaplan A H , Gilligan P H , Facklam R R
Published: January 2020

We report a case of a patient undergoing hemodialysis who developed a wound infection and subsequently bacteremia with a strain of vancomycin-resistant enterococcus identified as Enterococcus gallinarum. He had been receiving vancomycin prophylaxis before developing these infections. Both isolates were susceptible to ampicillin, rifampin, teicoplanin, and daptomycin (LY146032).
Endophthalmitis caused by Rhodococcus equi Prescott serotype 4
Authors: Ebersole L L , Paturzo J L
Published: January 2020

Rhodococcus equi, an aerobic actinomycete primarily known as a livestock pathogen, was repeatedly isolated from the severely infected right eye of a 9-year-old boy.
Rapid detection (4 h) of methicillin-resistant Staphylococcus aureus by a bioluminescence method
Authors: Park C H , Hixon D L , McLaughlin C M , Cook J F
Published: January 2020

A 4-h bioluminescence method for methicillin susceptibility determination was compared with reference methods. Of the Staphylococcus aureus strains tested, 80 were methicillin resistant, 180 were methicillin susceptible, and 10 were borderline susceptible. There was 100% correlation between bioluminescence and reference methods for methicillin-susceptible and methicillin-resistant strains. All borderline-susceptible strains were identified as methicillin resistant by bioluminescence.
Rapid identification of Branhamella catarrhalis with 4-methylumbelliferyl butyrate
Authors: Vaneechoutte M , Verschraegen G , Claeys G , Flamen P
Published: January 2020

Branhamella catarrhalis can be distinguished from Neisseria spp. by the presence of butyrate esterase. This enzyme can be rapidly detected when 4-methylumbelliferyl butyrate is used as the substrate. All B. catarrhalis strains tested gave a positive fluorescence reaction within 5 min, while Neisseria spp. remained negative, even after 18 h of incubation.
Effect of dexamethasone on detection of herpes simplex virus in clinical specimens by conventional cell culture and rapid 24-well plate centrifugation
Authors: Woods G L , Mills R D
Published: January 2020

During a 4-month period, two methods for rapid detection of herpes simplex virus (HSV) were examined: (i) pretreatment of A549 cells with dexamethasone for conventional tissue culture (277 specimens) and (ii) 24-well plate centrifugation using A549 cells with and without dexamethasone pretreatment and staining with serotype-specific monoclonal antibodies (Syva Co., Palo Alto, Calif.) after incubation for 16 to 18 h (153 specimens). By conventional tube cell culture, both with and without dexamethasone, HSV was identified in 88 of 277 (32%) specimens. Significantly more specimens were positive for HSV at 24 h (46 versus 27 specimens) and at 48 h (a total of 72 versus 59 specimens) (P less than 0.0001) in dexamethasone-treated A549 cells. Of the 153 specimens tested by conventional culture and 24-well plate centrifugation, HSV was detected in 44 (29%) by conventional culture, and by 24-well plate centrifugation with and without dexamethasone, HSV was detected in 32 (21%) and 30 (20%) specimens, respectively. The sensitivity, specificity, and positive and negative predictive values of 24-well plate centrifugation with A549 cells for detection of HSV were 73 (71% without dexamethasone), 100, 100, and 90%, respectively. In conventional tube cell culture, pretreatment of A549 cells with dexamethasone results in more rapid detection of HSV. Centrifugal inoculation of dexamethasone-treated and untreated A549 cells in 24-well plates and staining with monoclonal antibodies after incubation for 16 to 18 h is an insensitive means to detect HSV in clinical specimens and should not replace conventional tube cell culture.