bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbiological Profiles of Four Apollo Spacecraft
Authors: Puleo J. R. , Oxborrow G. S. , Fields N. D. , Herring C. M. , Smith L. S.
Published: December 2020

Selected surfaces from the Command Module, Lunar Module (ascent and descent stages), Instrument Unit, Saturn S-4B engine, and Spacecraft Lunar Module Adapter comprised the various components of four Apollo spacecraft which were assayed quantitatively and qualitatively for microorganisms. In addition, the first Lunar Roving Vehicle was assayed. Average levels of microbial contamination (10
4
per square foot of surface) on the Command Module, Instrument Unit, and Saturn S-4B engine were relatively consistent among spacecraft. The first postflight sampling of interior surfaces of the Command Module was possible due to elimination of the 21-day back-contamination quarantine period. Results of the pre- and postflight samples revealed increases in the postflight samples of 3 logs/inch
2
. A total of 5,862 microbial isolates was identified; 183 and 327 were obtained from the Command Module at preflight and postflight sampling periods, respectively. Although the results showed that the majority of microorganisms isolated were those considered to be indigenous to humans, an increase in organisms associated with soil and dust was noted with each successive Apollo spacecraft.
Degradation of Parathion by Bacteria Isolated from Flooded Soil
Authors: Siddaramappa R. , Rajaram K. P. , Sethunathan N.
Published: December 2020

Two bacteria,
Bacillus
sp. and
Pseudomonas
sp., were isolated from parathionamended flooded alluvial soil which exhibited parathion-hydrolyzing ability.
Bacillus
sp. readily liberated nitrite from the hydrolysis product,
p
-nitrophenol, but not from intact parathion.
Pseudomonas
sp. hydrolyzed parathion and then released nitrite from
p
-nitrophenol. These studies establish bacterial degradation of parathion past the
p
-nitrophenol stage to the end product, nitrite.
Evaluation of the PathoTec “Rapid I-D System” and Two Additional Experimental Reagent-Impregnated Paper Strips
Authors: Rosner Richard
Published: December 2020

The PathoTec “Rapid I-D System” and two experimental test strips for ornithine decarboxylase and beta-galactosidase have been evaluated for accuracy and ability to identify 1,252 members of the
Enterobacteriaceae
obtained from fresh clinical specimens. Accuracy of identification with the commercially available test system was 94.7%; this level increased to 98.5% with the addition of the two experimental test strips. Average individual accuracy of the 12-strip test system on a side-by-side basis with similar conventional procedures was 98%. In addition, 103 gram-negative nonfermentors were accurately grouped. The PathoTec System was applicable to 95% of the primary isolation plates used and provided biochemical data within 4 h after inoculation. The conventional test procedures were applicable to 100% of the primary isolation plates used and produced data within 48 h.
Assimilation of Hydrocarbons by
Pseudomonas
Strains Isolated from Human Clinical Specimens
Authors: Duncan Joycelyn , Ulrich John
Published: December 2020

Twenty strains of
Pseudomonas
isolated from human clinical specimens on routine laboratory media, without hydrocarbon enrichment and unselected for their growth on hydrocarbons, were tested for their ability to utilize a series of eight
n
-alkanes and two 1-alkenes as a sole carbon and energy source for growth. Hydrocarbon assimilation does occur with such isolates relative to the chain length and the degree of saturation of the hydrocarbon. The data presented show that all 16 stains of
Pseudomonas aeruginosa
studied grew readily on dodecane through hexadecane and on 1-hexadecene. In addition, most strains of this species grew on undecane and 1-dodecene after prolonged incubation. There was a long lag period, usually a minimum of 4 days, before onset of growth on any hydrocarbon. In no case did hexane or decane support growth. Two strains each of
P. maltophilia
and
P. stutzeri
were unable to grow on any of the hydrocarbons tested. Hexane in concentrations above 1% (vol/vol) is bactericidal toward the
Pseudomonas
inoculum. It is toxic even to cells utilizing different hydrocarbon for growth. The addition of 1% hexane to 1% (vol/vol) hexadecane markedly prolonged the lag phase of
P. aeruginosa
utilizing the hexadecane for growth.
Recovery and Identification of Anaerobes: a System Suitable for the Routine Clinical Laboratory
Authors: Ellner Paul D. , Granato Paul A. , May Carolyn B.
Published: December 2020

A system for the isolation of anaerobes based upon the use of reducible solid media is described. Plates of reducible media prepared and stored aerobically were reduced before use by incubation in a GasPak jar for 24 h. Clinical specimens for culture were carefully selected. The value of Amies transport medium was confirmed. Selective and nonselective formulations of reducible media were used for primary isolation. Abbreviated identification schemes based in part on gas-liquid chromatography are presented. The suitability of this system for improving the recovery and identification of anaerobes in a routine clinical laboratory is documented.
Repair and Enumeration of Injured Coliforms in Frozen Foods
Authors: Warseck M. , Ray B. , Speck M. L.
Published: December 2020

Two strains of
Escherichia coli
manifested death and repairable injury after being frozen in water or sterile foods at -20 C. The injured survivors were inhibited from forming colonies on violet red bile agar (VRBA) or deoxycholate lactose agar; this inhibition was greater when enumeration was done by the pour plate method instead of the surface or surface-overlay method. Injured cells repaired rapidly in Trypticase soy broth (TSB), and the repair was about maximum after 1 h at 25 C. When the injured cells were added to different foods and incubated at 25 C, repair also occurred; however, recovery was better and more uniform when the samples were mixed with TSB and incubated 1 h at 25 C. Cell multiplication was not evident until after 90 to 120 min at 25 C. The enumeration of coliforms from commercially frozen foods was increased when the thawed samples were mixed with TSB and the cells were allowed to repair 1 h at 25 C. In some samples, the repair permitted at least a 20-fold increase in the coliform count. The associated flora in the commercially frozen foods gave no evidence of impairing the repair of coliforms, nor did they start multiplication prior to 90 min after being incubated in TSB at 25 C. Generally, the plating gave more reproducible recovery of coliforms than did the most probable number method. Also, a higher number of coliforms were obtained by the surface-overlay method of plating using VRBA.
Thermal Inactivation of Staphylococcal Enterotoxins B and C
Authors: Fung Daniel Y. C. , Steinberg Dennis H. , Miller Richard D. , Kurantnick Marilyn J. , Murphy Thomas F.
Published: December 2020

Thermal inactivation profiles of staphylococcal enterotoxins B (SEB) and C (SEC) at 80, 100, and 121 C showed that SEC is more resistant than SEB to heat. After 24 h of incubation at 25 C, some reactivation (recovery of serological reactivity) occurred in toxins that had been inactivated by heat. If the toxin was stirred during heating, reactivation did not occur. An examination of the reactivation kinetics of heat-treated SEC showed that reactivation was temperature dependent. At 25 C, the incubation temperature of heat-treated crude SEC (80 C for 10 min), 100% reactivation occurred after 24 h, whereas at 4 C only slight reactivation was observed. We and others observed that heat-treated toxins initially lost more serological activity when heated at a low temperature (80 C) than at a higher temperature (100 C); in the present study we demonstrate that this is a reversible phenomenon.
Death and Lysis of Leptospirae When Cultured in Asbestos-Filtered Growth Media
Authors: Ellinghausen H. C.
Published: December 2020

Death and lysis of leptospirae, when cultured in asbestos-filtered bovine albumin polysorbate 80 media, was quantitated. The pathogens (virulent and avirulent) required 2 × 10
6
cells/ml to initiate growth in such media, whereas inocula of 2 to 20 cells/ml grew in control medium. Saprophytic leptospirae initiated growth from 2 cells/ml in asbestos-filtered medium as well as control medium. The adverse action of asbestos-filtered medium was not removed by storage of medium for 2 years at 25 C and was not diminished when such medium was frozen at -80 C. Washing with water, HCl and NaHCO
3
-NaCl, citric acid, and medium components did not remove the lytic activity associated with asbestos-filtered culture medium. Continuous subculture in asbestos-filtered medium was possible from large inocula; however, upon subsequent dilution and reinoculation into asbestos-filtered media, there was no evidence of acquired resistance, and all pathogens failed to grow.
Effects of Aflatoxin on Seeding Growth and Ultrastructure in Plants
Authors: Crisan Eli V.
Published: December 2020

Nineteen plants belonging to 11 species of the cruciferae were studied to determine the effects of aflatoxin B
1
on seed germination and seedling development. Germination was not inhibited in any test organism at a concentration of 100 μg of aflatoxin per ml of agar substrate. Inhibition of elongation of the hypocotyls and roots in the species studied varied from 29 to 93% and from 22 to 91% in the respective tissues.
Lepidium sativum
was the most susceptible plant studied and exhibited the maximal inhibitory response noted above at concentrations of 8 μg of aflatoxin per ml. The ultrastructure of
Lepidium
root cells treated with crystalline aflatoxin B
1
exhibited morphological changes characteristic of those found in aflatoxin-treated animal cells. In addition to changes in the cytoplasmic organelles, numerous ring-shaped nucleoli with prominent nucleolar caps were produced. The effect of aflatoxin on plant cells is compared with similar effects induced by actinomycin D. Seed germination and seedling development is discussed in relation to the effects of both compounds on deoxyribonucleic acid-dependent ribonucleic acid biosynthesis.
Antibody to Viruses Affecting Cattle in Commercial Tissue Culture Grade Fetal Calf Serum
Authors: Rossi C. R. , Kiesel G. K.
Published: December 2020

Commercial fetal calf serum (FCS) for tissue culture use was tested for neutralizing activity against several viruses which affect cattle. Certain lots of FCS contained no neutralizing activity, whereas other lots contained neutralizing activity to several viruses. It was concluded that the neutralizing activity found in certain lots of sera was due to specific antibody and that its presence could be most easily explained by the contamination of the FCS with serum from postcolostral bovine serum. A nonantibody inhibitor to vesicular stomatitis virus was also found at low levels in most lots of serum. Because those sera which had antibody had antibody to several viruses, it was suggested that the use of the micro-serum neutralization test with a few bovine viruses which are widespread in the bovine population should be satisfactory to detect FCS which was contaminated with postcolostral bovine serum.
Factors Affecting Selectivity of Brilliant Green-Phenol Red Agar for Salmonellae
Authors: Moats W. A. , Kinner J. A.
Published: December 2020

Commercial brilliant green (BG)-sulfa agar was found to be nonselective toward a test series of
Enterobacteriaceae
. Various formulations of BG were prepared by using Trypticase soy agar (BBL) as a base. Results were more reproducible when BG dye was added after sterilization than before. Sulfonamides improved selectivity as compared with brilliant green alone. Sulfanilamide (SN) was slightly more selective for salmonellae than other sulfonamides tested. Bile salts and sodium dodecyl sulfate markedly reduced the toxicity of BG to all the test bacteria.
Enterobacter
strains were most difficult to inhibit. A combination of 5 mg of BG and 1 g of SN/liter prevented growth of
Proteus mirabilis
and
Escherichia coli
and retarded growth of
Enterobacter
strains. The BG-SN agars were superior in selectivity to a series of commercial agars tested, and numbers of salmonellae recovered on BG-SN agar and Trypticase soy agar (BBL) were the same. Brilliant green agars with various degrees of selectivity are described.
Autecological Study of the Chemoautotroph
Nitrobacter
by Immunofluorescence
Authors: Fliermans C. B. , Bohlool B. B. , Schmidt E. L.
Published: December 2020

Fluorescent antibodies (FA) prepared for
Nitrobacter agilis
and
N. winogradskyi
were highly reactive in homologous staining. Low-level cross-reactions between the two species were removed by adsorption. All 15 pure-culture isolates of
Nitrobacter
tested reacted strongly with either
N. agilis
FA or
N. winogradskyi
FA. All pure-culture isolates from soils were determined to be
N. winogradskyi
; those from Mammoth Cave sediments and a cattle waste oxidation ditch were
N. agilis
. No cross-reaction was found in extensive tests that included five isolates of
Nitrosomonas europaea
and 668 heterotrophic aerobic and anaerobic bacteria isolated from soil, sewage, and cave sites. The FA preparations were used to detect
Nitrobacter
species in Mammoth Cave sediments, in a cattle waste oxidation ditch, and in surface waters and sediments of a river and to observe that
N. winogradskyi
can outgrow
N. agilis
in enrichment culture.
Pressure Transducer Method for Measuring Gas Production by Microorganisms
Authors: Wilkins Judd R.
Published: December 2020

A simple method for measuring gas production by microorganisms by using a pressure transducer to sense pressure buildup was developed and tested with members of the coliform group. The test system consisted of a 5.0 lb/in
2
pressure transducer and a pressure equalizer valve attached to the metal cap of a test tube (20 by 150 mm); gas pressure was recorded on a strip-chart recorder. Gas pressure response curves consisted of (i) a lag period with no marked increase in pressure, (ii) a rapid pressure buildup period, and (iii) a leveling-off period. A linear relationship was established between inoculum size and length of the lag period. Cultures shaken at 200 oscillations/min showed a marked increase in rate of gas release over stationary cultures. Cell concentrations at the time of rapid buildup in pressure were 10
8
/ml. Mean maximum pressure recordings, lb/in
2
per 10 ml of broth, were:
Enterobacter aerogenes
, 3.70;
Citrobacter intermedium
, 2.70; and
Escherichia coli
, 2.10. Mean CO
2
concentrations, ppm of headspace gas, for
E. coli
were: (i) 2,000 at time of inoculation, (ii) 25,000 at time of rapid buildup in pressure, and (iii) 150,000 at maximum pressure. These results indicate the potential application of the pressure transducer method for rapidly detecting coliforms and other gas-producing microorganisms in clinical samples and in sterility testing of foods.
Distribution of Streptococcal Groups in Clinical Specimens with Evaluation of Bacitracin Screening
Authors: Pollock Helen M. , Dahlgren Bonnie J.
Published: December 2020

During a 2-year period, 4,968 strains of beta-hemolytic streptococci were examined for the clinical source distribution and bacitracin sensitivity of each group. In the upper respiratory tract, groups A (51.7%) and C (20.4%) accounted for most of the isolates, and in wounds and exudates group A (79.1%) made up most of the isolates. Group B (71.2%) was the major component of isolates from the genitorinary tract and, while composing 29.3% of the lower respiratory tract isolates, competed with group A (18.8%) and the nongroupables (22.8%) for supremacy. Bacitracin screening showed that 0.5% of group A streptococci were resistant, and sensitive non-group A isolates were group B (2.6%), group C (6.0%), group G (8.0%), and the nongroupables (2.2%). It was found that those groups which were most predominant in wounds and the upper respiratory tract gave the highest rate of false positives with bacitracin, whereas the predominant group of the genitourinary tract gave the lowest rate of false positives.
Inactivated Venezuelan Equine Encephalomyelitis Vaccine Prepared from Attenuated (TC-83 Strain) Virus
Authors: Cole Francis E. , May Stephen W. , Eddy Gerald A.
Published: December 2020

Formalin-inactivated Venezuelan equine encephalomyelitis vaccine was prepared from virus propagated in rolling-bottle cultures of chicken embryo cells. The attenuated, TC-83 strain of virus was propagated in these cultures with a maintenance medium consisting of serum-free medium 199 containing 0.25% human serum albumin and antibiotics. By adjustment of maintenance medium volume (100 to 300 ml) and multiplicity of inoculum (0.04 to 0.00004), high-titered yields of virus were obtained with minimal cell destruction at convenient harvest times, viz, 18 to 24 h postinoculation. Inactivation of virus at 37 C was complete between 8 to 10 h with 0.05% Formalin and within 6 to 8 h with 0.1% Formalin. Antigen extinction potency tests in mice indicated that potent vaccines could be produced at both Formalin concentrations and, furthermore, that potency was not adversely affected by inactivation periods of up to 96 h.
Cellulose Fermentation: Effect of Substrate Pretreatment on Microbial Growth
Authors: Han Y. W. , Callihan C. D.
Published: December 2020

The effects of chemical, physical, and enzymatic treatments of rice straw and sugarcane bagasse on the microbial digestibility of cellulose have been investigated. Treatment with 4% NaOH for 15 min at 100 C increased the digestibility of cellulose from 29.4 to 73%. Treatment with 5.2% NH
3
could increase digestibility to 57.0% Treatments with sulfuric acid and crude cellulase preparation solubilized cellulose but did not increase the digestibility. Grinding or high-pressure cooking of the substrate had little effect on increasing the digestibility of cellulosic substrates by the
Cellulomonas
species.
Different pH Optima in the Two Steps of an Indirect Fluorescent Antibody Reaction for
Clostridium botulinum
Type E
Authors: Robohm Richard A.
Published: December 2020

Quantitative measurements of the effects of ions on fluorescent antibody reactions have not been reported in the literature. Data in this report show the effects of ranges of H
+
, phosphate, Mg
2+
, and Ca
2+
molarities on antigen-antibody coupling during an indirect fluorescent antibody (IFA) reaction for
Clostridium botulinum
type E. These effects were quantified in two ways: (i) by microphotometric measurement of cell fluorescence intensity; and (ii) by visual estimation of cell fluorescence intensity on long glass strips treated with antibody in ion gradients. Optimal pH for the first part of the reaction (coupling of rabbit antibody to cells) was 7.25, and optimum in the second part (coupling of tracer globulin to the rabbit globulin) was pH 7.37. Running the reaction as little as 0.10 to 0.15 pH units off from the optima considerably reduced fluorescence intensity. Sodium phosphate buffer up to 0.1 M did not significantly affect either portion of the reaction. Ca
2+
and Mg
2+
showed no effect on the first part of the reaction. These results support the use of higher-strength phosphate buffer and indicate for the first time that IFA reactions may have two independent, narrow pH optima.
Rapid Method for Determining Serum Bactericidal Activity
Authors: Provonchee Richard B. , Zinner Stephen H.
Published: December 2020

To screen large numbers of sera, a method was devised which utilizes the Steers-Foltz replicator which is usually used to determine minimal inhibitory concentration for antibiotics. Each of the wells (9 by 15 mm) of the replicator is filled with 0.06 ml of serum, 0.02 ml of a 10
5
suspension of organisms, and 0.02 ml of diluent (tris(hydroxymethyl)aminomethane-hydrochloride buffer, pH 8.4). The mixtures are incubated for 3 h, and samples are taken at 0, 1, 2, and 3 h by stamping duplicate nutrient agar plates (approximately 0.04 ml from each well). Plates are incubated overnight, and bactericidal activity is estimated by visual inspection of bacterial growth at each site for each sampling time. Results obtained with 28 serum-organism pairs paralleled standard pipetting-pour plate methods. The replicator method for determining bactericidal activity allows for the testing of a large number of samples and requires negligible amounts of serum.
Antibacterial Effect of Cysteine-Nitrosothiol and Possible Percursors Thereof
Authors: Incze K. , Farkas J. , Mihályi Vilma , Zukál E.
Published: December 2020

The postulated intermediate of nitrite-myoglobin reaction, cysteine-nitrosothiol, was prepared and its antibacterial effect was tested on
Salmonella
strains,
Streptococcus faecium
, and spores and vegetative cells of
Clostridium sporogenes
. Cysteine-nitrosothiol showed a higher inhibitory effect than nitrite. Preliminary results on the effect of simultaneous use of nitrite and cysteine on
Clostridium sporogenes
spores were also presented.
Lysogenic Strains of Group N Lactic Streptococci
Authors: Lowrie R. J.
Published: December 2020

A temperate bacteriophage, designated r
1
t, was inducible from the group N lactic streptococcus,
Streptococcus cremoris
R
1
, by ultraviolet irradiation or mitomycin C treatment. Induced lysates produced plaques on lawns of three closely related
S. cremoris
strains, AM
1
, SK
11
, and US
3
. Strain SK
11
was readily lysogenized.
S. cremoris
AM
1
was the most reliable indicator strain, although the age of the culture used for seeding plates was critical. Zones of lysis but no plaque formation were observed on lawns of nine additional
S. cremoris
strains. Phage r
1
t could not be detected in filtrates of stationary-phase R
1
cultures and was near the limits of detection in logarithmically growing cultures. Phage levels were still very low (1 plaque-forming unit on AM
1
per 10 induced cells) in induced lysates of R
1
cultures. These low levels of detectable phage may be attributable to an inadequate indicator, lysogenization of the indicator, adsorption of induced phage to cellular debris, concurrent induction of other undetectable phages, or the production of high proportions of defective phages. Electron micrographs of induced R
1
lysates revealed a high incidence of incomplete phage particles, fragments, and ghosts.
Adaptation and Infection of Mouse Bone Marrow (JLS-V9) Cells in Suspension Culture for Production of Rauscher Leukemia Virus
Authors: Hodge Howard M. , Klein Frederick , Bandyopadhyay Alok K. , Robinson Orson R. , Shibley George P.
Published: December 2020

JLS-V9 mouse bone marrow cells were readily adapted to suspension culture, chronically infected with Rauscher leukemia virus (RLV), and subsequently grown in 7.5- and 14-liter New Brunswick fermentors. The suspension-type cell system can be modified to produce virus with clearly defined properties, such as high ribonucleic acid-dependent deoxyribonucleic acid polymerase (RDDP) activity, high particle count, and high infectious particle count. Biological and biophysical properties of suspension-produced RLV were not affected by concentration and purification employing continuous-flow and rate-zonal centrifugation procedures. The RDDP assay was standardized and showed a linear incorporation of
3
H-thymidine 5′-monophosphate (
3
H-TMP) up to 30 min. Further characterization indicated that a high percentage of
3
H-TMP incorporation was due to RDDP.
Morphological Observations of
Diplodia maydis
on Synthetic and Natural Substrates as Revealed by Scanning Electron Microscopy
Authors: Murphy Judith A. , Campbell L. Leon , Pappelis A. J.
Published: December 2020

Mycelial and spore morphology of
Diplodia maydis
were investigated by using scanning electron microscopy after growth on various media and natural substrates (oat and corn kernels, and corn husks). Of several specimen preparation methods studied, Parducz fixation followed by critical-point or freeze-drying gave adequate preservation for pycnidia, mycelia, and spores. Morphological characteristics were similar in rotary and reciprocal shaker cultures and differed from that found in stationary cultures in the amount of slime-like material produced and precipitated matter on the mycelial surfaces. In general, mycelial surfaces were smooth. Large areas of coalesced material were present in all samples examined. Slime-like material produced in liquid media appeared as a finely laced net, randomly appearing throughout the mycelia with bead-like structures present along the net. A fine netting also was observed interspersed among the spores inside the pycnidia obtained from oats. Slime-like material was observed to cover the pycnidia produced on oat and corn kernels. In the latter case, the spores were less protected by the outer slime-like covering. Thickened node-like structures were observed in mycelial mats produced in modified Fries 2 medium, on potato dextrose agar plates, and on infected oats. Round and ovate thickened node-like structures were observed in mycelium produced on corn kernels. In general, node-like structures were less abundant in mycelia from naturally infected substrates. Conidia were commonly rounded to tapered and two celled, with a distinctive ridged septum at the middle. Dried spores were collapsed in a characteristic flask-like fashion.
Interconversion of Type C and D Strains of
Clostridium botulinum
by Specific Bacteriophages
Authors: Eklund M. W. , Poysky F. T.
Published: December 2020

These studies show that
Clostridium botulinum
types C and D cultures can be cured of their prophages and converted to either type C or D depending on the specific phage used. Strains of types C and D were cured of their prophages and simultaneously ceased to produce their dominant toxins designated as C
1
and D, respectively. Cured nontoxigenic cultures derived from type C strain 162 were sensitive to the phages from the toxigenic type C strain 162 and type D strain South African. When cured nontoxigenic cultures derived from strain 162 were infected with the tox
+
phages from the 162 strain of type C and the South African strain of type D, they then produced toxin neutralized by types C and D antisera, respectively. Cured nontoxigenic cultures isolated from the type D South African strain were only sensitive to the parent phage, and, when reinfected with the tox
+
phage, they produced toxin neutralized by type D antiserum. Type C strain 153 and type D strain 1873, when cured of their respective prophages, also ceased to produce toxins C
1
and D, but, unlike strain 162 and the South African strain, they continued to produce a toxin designated as C
2
. When the cured cultures from strains 153 and 1873 were infected with the tox
+
phage from type D strain 1873, the cultures simultaneously produced toxin that was neutralized by type D antiserum. When these cured cultures were infected with the tox
+
phage from type C strain 153, the cultures produced toxin that was neutralized by type C antiserum. These studies with the four strains of
C. botulinum
confirm that the toxigenicity of types C and D strains requires the continued participation of tox
+
phages. Evidence is presented that types C and D cultures may arise from a common nontoxigenic strain.
Gradient Technique to Test the Effects of Substances on Fluorescent Antibody Reactions
Authors: Robohm Richard A.
Published: December 2020

A simple technique is described for making gradients of substances, applying them to bacterial cells during fluorescent antibody reactions, and observing their effects.
Evaluation of an Automated Colony Counter
Authors: Goss W. A. , Michaud R. N. , McGrath M. B.
Published: December 2020

An automated colony counter was found to readily detect surface and subsurface bacterial colonies of 0.3-mm size or greater with a high degree of precision. On a logarithmic scale, counting efficiency consistently ranged from 89 to 95% of corresponding manual count determinations for plates containing up to 1,000 colonies. In routine application, however, automated plate counts up to approximately 400 colonies were selected as a more practical range for operation. The automated counter was easily interfaced with an automated data acquisition system.
Simplified Method for the Purification of Group A Streptococcal M-Proteins: Solution of the Multiple Banding Problem
Authors: Straus David C. , Mehta Aruna , Lange Charles F.
Published: December 2020

A simple and rapid procedure for the isolation in high yield (about a 30% recovery based on the total 30 to 60% ammonium sulfate recovery) of homogeneous purified group A streptococcal M-protein is described. M-proteins extracted from whole cells of group A streptococci by treatment with hot HCl were neutralized, fractionated with ammonium sulfate, dialyzed, lyophilized, and then subjected to treatment with hot 60% trichloroacetic acid. This was shown to produce an M-protein preparation, free of group A carbohydrate activity and extraneous antigens, in yields up to 10-fold higher than previous methods in about one-fifth the time. These M-protein preparations were shown to: (i) have similar amino acid compositions to their respective type-specific proteins purified by diethylaminoethyl and
O
-(carboxymethyl) cellulose chromatography, (ii) react with their respective type-specific antisera in Ouchterlony diffusion, (iii) produce antisera in rabbits capable of promoting streptococcal long-chain formation in vitro, and (iv) give only one major band on polyacrylamide gel disk electrophoresis. The data allow for an explanation of the hitherto described multiple banding M-proteins seen on acrylamide electrophoresis.
Velocity Measurements of Motile Bacteria by Use of a Videotape Recording Technique
Authors: Schneider W. R. , Doetsch R. N.
Published: December 2020

A method has been developed to measure accurately the velocity of motile bacteria
Bacterial Culture Longevity: Control by Inorganic Phosphate and Temperature
Authors: Smith D. K. , Benedict C. D. , Weinberg E. D.
Published: December 2020

Death of cells in cultures of six species of gram-negative bacteria was accelerated by incorporation in the medium of 10-fold more inorganic phosphate than was needed for growth. Death induced by inorganic phosphate was independent of the carbohydrate employed and was enhanced by warm temperatures.
Medium Containing Trypan Blue and Antibiotics for the Detection of
Cryptococcus neoformans
in Clinical Samples
Authors: Vickers Richard M. , McElligott James J. , Rihs John D. , Postic Bosko
Published: December 2020

A medium containing trypan blue, gentamicin, and chloramphenicol is introduced for the detection of
Cryptococcus neoformans
and
Cryptococcus
species from clinical samples. Ten recently isolated strains of
Cryptococcus
species as well as several clinical isolates of
C. neoformans
incorporated trypan blue and produced dark blue colonies on this mycological medium, whereas other common yeasts were light blue. The laboratory diagnosis of two cases of cryptococcosis was accomplished by the isolation of
C. neoformans
on the antibiotic-dye-containing medium. Compared to conventional media supporting large numbers of
Pseudomonas aeruginosa
and other gram-negative bacilli, the new medium was selective for yeasts. In one instance, the colonization of the respiratory tract by
C. neoformans
which led to fungemia was traced by the use of the antibiotic-dye medium. The antibiotic mixture, utilized herein, was more effective in suppressing bacteria contained in samples from patients than a medium containing cycloheximide and chloramphenicol.
Salmonella
in Natural Animal Casings
Authors: Gabis D. A. , Silliker J. H.
Published: December 2020

Destruction of salmonellae in inoculated and naturally contaminated natural animal casings was studied. Salmonellae were effectively destroyed (99.999%) in inoculated hog casings after exposure for 24 h to saturated brine at pH 4.0 and 10.0 adjusted with acetic acid and sodium hydroxide, respectively. Treatment of inoculated hog and sheep casings in saturated brine or saturated brine with citric acid was not nearly as effective as brine containing acetic acid or sodium hydroxide. Salmonellae in naturally contaminated hog casings were virtually eliminated after 21 days of storage in crystalline sodium chloride. Salmonella in sheep and hog casings were eliminated after 7 days of storage in crystalline salt. Treatment of naturally contaminated hog casings with glycerin-salt or sorbitol-salt solutions was not as effective in destroying salmonellae as treatment with crystalline salt.
Preparation and Storage of High-Titer Lactic Streptococcus Bacteriophages
Authors: Nyiendo J. , Seidler Ramon J. , Sandine W. E. , Elliker P. R.
Published: December 2020

Various techniques were employed for preparation of high-titer bacteriophage lysates of
Streptococcus lactis, S. cremoris
, and
S. diacetilactis
strains. Infection of a 4-h host culture in litmus milk at 30 C yielded the highest titers (2 × 10
9
to 4 × 10
11
plaque-forming units/ml) for most phages. Host infection in lactose-containing broth produced similar virus numbers only when 0.1 M tris(hydroxymethyl)aminomethane buffer stabilized the pH. The pH at the time of infection as well as the inoculum phage titer were critical in obtaining high titers. Optimum conditions for infection in broth were coupled with a polyethylene glycol concentration procedure to routinely produce milligram quantities of phage from 1 liter of lysate. Neutralization of whey lysates, as a means of storage, offered no survival advantage over unneutralized samples. Storage of phage lysates in a 15% glycerol whey solution at -22 C yielded a high rate of survival in most cases, even with repeated freezing and thawing, over a period of 24 months.
Evaluation of Methods for Isolating
Salmonella
and
Arizona
Organisms from Pet Turtles
Authors: Wells Joy G. , Clark Grace McConnell , Morris George K.
Published: December 2020

Two methods for isolating
Salmonella
and
Arizona
organisms from turtles, blending and excretion, were evaluated, and the percentage of isolates obtained by each method was compared with the percentage of isolates obtained by culture of turtle organs. The blending and excretion methods were equally effective in detecting the overall incidence of
Salmonella
and
Arizona
infections in turtles. The percentage of isolates obtained by specific organ culture, however, was less than the percentage obtained by the other two methods. The blending method detected a greater number of turtles with
Arizona
infections than did the excretion method, but there was no difference in the number of
Salmonella
infections detected by the two methods. The frequency of isolation of
Arizona
organisms from organs other than the small intestine and colon was higher than that of
Salmonella
.
Urbanization and the Microbial Content of the North Saskatchewan River
Authors: Coleman R. N. , Campbell J. N. , Cook F. D. , Westlake D. W. S.
Published: December 2020

The effect of urbanization on the microbial content of the North Saskatchewan River was determined by following the changes in the numbers of total bacteria, total eosin methylene blue (EMB) plate count, and
Escherichia coli
as the river flowed from its glacial source, through parklands, and out into the prairies. Changes in physical parameters such as pH, temperature, salt concentration, and the amount and nature of the suspended material were also determined to evaluate their on the microbial parameters being measured. The level of all three microbial parameters studied slowly increased as the river flowed from its glacial source out into the prairies. The major effect of small hamlets, with or without sewage treatment facilities, appears to be to supply nutrients which supports the growth of the indigenous river flora but not
E. coli
. In contrast, the effect of a large urban center, with a population of approximately 500,000, which utilizes primary and secondary sewage processes in disposing of sewage, is to provide the nutrients and an inoculum of
E. coli
which results in a marked increase in the numbers of all three microbial groups studied. The effect of this urban center was still discernible 300 miles downstream. The river was also monitored for the presence of
Salmonella
sp. Only one positive isolation was achieved during this study, and this isolate was characterized as being
Salmonella alachua
.
Small-Sample Blood Culture Method for Identification of Bacteria in Central Arterial and Peripheral Blood
Authors: Jennings Paul B. , Crumrine Martin H. , Fischer Gerald W. , Cunningham Thomas C.
Published: December 2020

A blood culture technique that utilized small arterial blood samples or peripheral capillary blood was tested in beagle dogs and pig-tailed macaque monkeys. A bolus of 2.0 × 10
7
Escherichia coli
(ATCC 25922) was injected intravenously into five animals of each species. Blood samples were taken before injection of the organisms and 10, 15, 20, 30, 60, and 120 min after injection. Arterial blood samples (2.0 and 0.2 ml) and peripheral capillary samples (0.14 ml) were taken at each sampling time. Pour plates were prepared from arterial blood for colony counts. All three blood sampling methods were equally effective in detecting sepsis when 10 or more organisms per ml of blood were present. Below this level, the 2.0-ml sample was more effective. Contamination of the peripheral sample with air or skin contaminants was a problem.
New Gas Chromatographic Characterization Procedure: Preliminary Studies on Some
Pseudomonas
Species
Authors: Wade Thomas J. , Mandle Robert J.
Published: December 2020

Strains of saccharolytic and nonsaccharolytic
Pseudomonas
species were examined by a new single-step gas chromatographic characterization procedure. Cells were digested in a methanolic solution of tetramethylammonium hydroxide pentahydrate, and the digestates were subjected to gas-liquid chromatographic analysis. The chromatograms were examined for similarities and differences in their overall patterns. A single component was defined for use as an internal qualitative and quantitative standardizing component in order to develop relative retention time-relative peak height profiles of each organism. Comparison of these profiles enabled the characterization of strains of
Pseudomonas aeruginosa, P. putida, P. cepacia, P. pseudomallei, P. stutzeri, P. pseudoalcaligenes, P. alcaligenes, P. diminuta, P. denitrificans
, and
P. acidovorans
. The
P. maltophilia
and
P. putrefaciens
digestates showed chromatograms which were superficially similar yet easily distinguished as belonging to different species. The chromatograms of these two organisms were very different from those of other pseudomonads.
Compound Inhibitory to
Clostridium botulinum
Type E Produced by a
Moraxella
Species
Authors: Kwan P. L. , Lee J. S.
Published: December 2020

A
Moraxella
strain, A-43, produced a compound inhibitory to the outgrowth of
Clostridium botulinum
type E spores. The inhibitor could be produced in various laboratory media, and the outgrowth of germinated spores was inhibited by a 1/10th dilution of the A-43 spent medium. Germination was not affected. Molecular weight of the inhibitor was estimated at 800 to 1,000. The inhibitor was dialyzable and could be concentrated by lyophilization. It was stable at 37, 25, and 5 C, but was 70% inactivated when heated at 65 C for 10 min. The inhibitor was not volatile and could not be vacuum-distilled at 40 C. Solutions of acids with pH values below 2.0 destroyed the activity. The A-43 inhibitor appears to be similar, in molecular weight and inhibition characteristics, to tylosin.
Toxic Metabolite Produced by
Aspergillus wentii
Authors: Wu M. T. , Ayres J. C. , Koehler P. E. , Chassis G.
Published: December 2020

Mycelial extracts of an
Aspergillus wentii
strain grown on yeast-extract sucrose medium and initially isolated from country-cured ham were highly toxic when inoculated into chicken embryos or fed to mice. Moldy corn and rice were less toxic when fed to mice. Water extracts of moldy corn or rice or culture filtrates from yeast-extract sucrose medium were not toxic. Purification by thin-layer chromatography followed by crystallization yielded orange-red crystals that showed high toxicity and had a melting point of 285 to 286 C. Chloroform solutions of the crystals had absorption maxima at 270, 295, and 452 nm. The smallest amount of this component necessary to have zero hatchability of fertile eggs was 50 μg/egg.
Polygalacturonate Lyase Production by
Bacillus subtilis
and
Flavobacterium pectinovorum
Authors: Ward Owen P. , Fogarty William M.
Published: December 2020

Nutritional factors relating to the production of polygalacturonate lyases by strains of
Bacillus subtilis
and
Flavobacterium pectinovorum
were examined. Studies were carried out in shake flask cultures. In the case of
B. subtilis
the enzyme was produced constitutively, whereas in the case of
F. pectinovorum
it was only produced in quantity in the presence of pectic substances. Glucose was the most suitable carbon source for production of the polygalacturonate lyase of
B. subtilis
; of the nitrogen sources examined, the highest activities per milliliter of supernatant and per milligram of cells were obtained with glutamine and ammonium sulfate, respectively. The pattern of enzyme production and growth was similar although enzyme production ceased at pH 5.3. Sodium polypectate was the best inducer of polygalacturonate lyase with
F. pectinovorum
. Highest activity per milliliter of cell-free supernatant was obtained with skin milk powder as nitrogen source, although ammonium sulfate gave highest enzyme production per unit of biomass. Growth of
F. pectinovorum
occurred between pH 5.7 and 7.2. Enzyme production occurred during active growth and was independent of the pH of the medium.
Antibody Responses in Rabbits to Injections of Whole Cell, Flagella, and Flagellin Preparations of Cholera and Noncholera Vibrios
Authors: Smith Harry L.
Published: December 2020

Sera prepared by the injection of living cells, killed cells, flagella, or flagellins of vibrios into rabbits were examined for antibodies which cross-reacted with cholera and noncholera vibrio strains. Antisera to
Vibrio cholerae
strains agglutinated heterologous
V. cholerae
strains. They did not agglutinate strains of noncholera vibrios. Sera to noncholera strains agglutinated homologous strains only. There was no evidence that a common antigen was present in the organisms tested. The proposal for a “cholera group of vibrios” based upon sharing of an H antigen between cholera and some noncholera vibrios is held as untenable. It is indicated, however, that the use of serotyping of vibrios could be used as an added tool for better identification or description of vibrios.
Soil Ecology of
Coccidioides immitis
at Amerindian Middens in California
Authors: Lacy George H. , Swatek Frank E.
Published: December 2020

Outbreaks of coccidioidomycosis and isolation of
Coccidioides immitis
have been reported from Amerindian middens. This study was undertaken to determine the most important ecological component(s) for the occurrence of
C. immitis
at archeological sites. Soils from 10 former Indian villages with no prior history of coccidioidal infection were collected and cultured. The physicochemical properties of the midden soils were compared with nonmidden soils and positive soils. The following theories for the sporadic distribution of the pathogen in the soil of the Lower Sonoran Life Zone were considered: (i) the
Larrea tridentata
(creosote bush) association, (ii) the preference for saline soils, (iii) isolation near rodent burrows, and (iv) animals as possible agents of dispersal. Results showed that a high percentage of the midden soils contained
C. immitis
, whereas none of the adjacent, nonmidden soils yielded the fungus. Physicochemical analyses revealed that the dark color and alkaline pH of the midden soils were due to past organic contamination. Repeated isolations were made from soils with low to moderate alkalinity. Alkalinity and sandy texture were consistent features of all soils in this study. However, the lack of any reports of nonsandy infested soils possibly indicates that the sandy texture and alkalinity may be factors in the distribution of this fungus. The organic content, soil parent material, and color were not important in the soil ecology.
L. tridentata
was not significant in the macroflora at the infested sites surveyed. Samples collected without reference to rodent burrows yielded a high percentage of recoveries. Animals, although not the major natural reservoir, cannot be ignored as possible factors in the ecology of
C. immitis
.
Ammonium Sulfate Fractionation of Sera: Mouse, Hamster, Guinea Pig, Monkey, Chimpanzee, Swine, Chicken, and Cattle
Authors: Hebert G. Ann
Published: December 2020

Optimal (NH
4
)
2
SO
4
concentrations were sought for serum fractionation in order to obtain the gamma globulin as free as possible from other serum components while maintaining a reasonable recovery. Various ammonium sulfate concentrations were used to fractionate sera from mice, hamsters, guinea pigs, monkeys, chimpanzees, swine, chicken, and cattle. All precipitates and supernatants were analyzed by electrophoresis to study the effects of various treatments on the composition of these materials. Approximately 75% of all the gamma globulins were recovered when each serum was fractionated with its optimal sulfate concentration. These optimals were determined to be as follows: three precipitations in 35% saturated ammonium sulfate (SAS) for hamster, chimpanzee, swine, and chicken serum; one precipitation in 35% SAS followed by two in 40% SAS for mouse and guinea pig serum; one precipitation in 30% SAS and then two in 40% SAS for monkey serum; and one precipitation in 30% SAS followed by two in 35% SAS for cattle serum.
Simplified Sugar Fermentation Plate Technique for Identification of
Neisseria gonorrhoeae
Authors: Taylor George S. , Keys Reginald J.
Published: December 2020

A simplified sugar fermentation technique incorporating (i) a glucose and (ii) a maltose, lactose, and sucrose plate was developed for confirming large numbers of
Neisseria gonorrhoeae
cultures.
Evaluation of Frozen Fixed Smears for Use in Fluorescent Antibody Studies of Salmonellae
Authors: Thomason Berenice M.
Published: December 2020

Smears of broth cultures of 28
Salmonella
serotypes were fixed with Kirkpatrick fixative and stored at -20 C. Results indicate that organisms retain the ability to stain at maximal fluorescence intensity for as long as 2 years.
Evaluation of Three Media for Selective Isolation of Gram-Positive Bacteria from Burn Wounds
Authors: Dayton Sandra L. , Chipps Donna D. , Blasi Dianna , Smith R. F.
Published: December 2020

Three media, phenylethyl alcohol blood agar, esculin-mannitol agar, and Columbia CN blood agar, were studied for the selective isolation of gram-positive bacteria from swab cultures of burn wounds.
Production of Citrinin by
Penicillium viridicatum
on Country-Cured Ham
Authors: Wu M. T. , Ayres J. C. , Koehler P. E.
Published: December 2020

Seven strains of
Penicillium viridicatum
isolated from country-cured ham produced citrinin in potato dextrose broth and on country-cured ham. None of the strains produced detectable amounts of citrinin at 10 C. The optimal temperature range for citrinin production was 25 to 30 C.
Stress: a Factor to be Considered in Heterotrophic Microorganism Enumeration from Aquatic Environments
Authors: Klein Donald A. , Wu Shenyuh
Published: December 2020

Heterotrophic microorganisms in water samples are susceptible to the transient stress of warmed agar used in the standard methods pour plate procedure, causing significantly decreased recoveries in comparison with a spread plate technique. Microbial starvation can increase susceptibility to a transient warming stress. The standard plate count procedure, as presently described, should not be considered for quantitation of microorganisms from aquatic environments.
Isolation of
Vibrio parahaemolyticus
from Salt Springs in Florida
Authors: Koburger John A. , Lazarus Charles R.
Published: December 2020

Vibrio parahaemolyticus
was isolated from various locations in two salt springs of Florida and appears to be a normal inhabitant of these artesian waters.