bluuebunny/crossref_metadata_2025 huggingface dataset:
Cellulolysis by
Mucor pusillus
Authors: Somkuti G. A. , Babel F. J. , Somkuti A. C.
Published: December 2020

Culture filtrates of
Mucor pusillus
NRRL 2543 contained hydrolytic enzymes that attacked native cellulose, acid-swollen cellulose, carboxymethylcellulose, and cellobiose. The distribution profiles of cellulolytic and β-glucosidase activities after gel filtration on Sephadex G-75 showed the presence of several active peaks. Glucose was the only product of hydrolysis when native cellulose was used as the substrate. Acid-swollen cellulose, when treated with cellulase free of β-glucosidase activity, gave rise to glucose, cellobiose, and at least two higher molecular weight components which were also hydrolyzed in turn to cellobiose and glucose. The presence of a multiple cellulolytic enzyme system was indicated, the components of which may have specific roles in the degradation of cellulose.
Evaluation of Two Spot-Indole Reagents
Authors: Lowrance B. L. , Reich P. , Traub W. H.
Published: December 2020

Two spot-indole reagents,
p
-dimethylaminobenzaldehyde (DMABA) and
p
-dimethylaminocinnamaldehyde, were evaluated quantitatively. Although fourfold less sensitive, DMABA proved to be more stable and economical.
Simple Method for the Separation of Ascospores
Authors: Partsch G.
Published: December 2020

A simple method for the separation of ascospores is described. To isolate single spores from adhesive ascospores and the mycelium, the suspension was sucked through a combination of sintered-glass plates with different pore sizes.
Group B Streptococci in Neonatal Deaths
Authors: MacKnight John F. , Ellis Patricia J. , Jensen Karen A. , Franz Barbara
Published: December 2020

Clinical microbiologists are reminded to look for group B streptococci in neonatal infants. We report four deaths, one with meningitis, occurring among 14 such infected newborn infants at our institution; of the nursing staff, 31% were also carriers of group B streptococci.
Methyl Anthranilate, an Inhibitor for the Germination of Spores of Aerobic Bacilli
Authors: Prasad Chandan , Srinivasan V. R.
Published: December 2020

Methylanthranilate inhibited the germination of spores of aerobic bacilli without affecting growth and sporulation. The inhibition of germination could not be reversed by removal of methylanthranilate.
Microbiological Evaluation of Incinerator Operations
Authors: Peterson Mirdza L. , Stutzenberger Fred J.
Published: December 2020

Incineration is currently a widely used method for the disposal of municipal solid waste in major American cities. The efficacy of several incinerator types to destroy bacteria associated with solid waste was evaluated, with emphasis on fecal and food sources. Samples of solid waste and its residue after incineration, taken from four incinerators of different design, were homogenized in phosphate buffer at
p
H 7.5. Samples of these homogenates were quantitatively examined for (i) total bacterial cell number, (ii) total coliforms, (iii) fecal coliforms, and (iv) heat-resistant spore-formers. Survival of coliforms in the residue after incineration was considered an indication of inadequate incinerator design or operation, or both. Of the four incinerators tested, only one produced residue devoid of fecal coliforms; three others produced residue containing fecal coliform populations of 5 to 2,400 per g. An inverse relationship was noted between the efficacy of incinerators in destroying fecal coliforms and the heat resistance (80 C) of total bacterial populations surviving in their respective residues. This could be due to the selection of heat-resistant cells during incineration.
Detection of Nuclease Activity in Semisolid and Broth Cultures
Authors: Lachica R. Victor F. , Deibel R. H.
Published: December 2020

A method for the detection of deoxyribonuclease activity in semisolid agar cultures was investigated. When cultures were overlaid with an acridine orangedeoxyribonucleate-agar (ADA) mixture, incubated for 1 to 3 hr, and observed under ultraviolet light, clear halos developed around colonies that produced deoxyribonuclease. A variation of the method for use with broth cultures involved impregnation of filter-paper discs with a small portion of the culture and overlaying the discs with the ADA mixture. This alteration has the advantage that the test tube cultures are easily heat-treated prior to assay to determine the heat resistance of the enzyme.
Protection Antisera Afford Against Death by Endotoxin
Authors: Rubenstein Howard S. , Worcester Jane
Published: December 2020

Whole antisera were shown to afford substantial protection against death from endotoxin in mice in an environment held constant at 22 C, but 19
S
or 7
S
antibodies acting alone did not afford significant protection.
Efficiency of a Multitest System (Enterotube) for Rapid Identification of
Enterobacteriaceae
Authors: Grunberg E. , Titsworth E. , Beskid G. , Cleeland R. , Delorenzo W. F.
Published: December 2020

Enterotube, a multiple-test system which combines nine biochemical tests useful in the identification of members of the family
Enterobacteriaceae
, was tested and compared with the PathoTec test system in the identification of gram-negative bacilli isolated from clinical specimens. It was found that both the Enterotube and the PathoTec systems rapidly and accurately defined the position of the organisms in the major groups of the family
Enterobacteriaceae
. Discrepancies were noted between the results of citrate tests on Simmons' citrate-agar and in the Enterotube, as well as between Simmons' citrate-agar and the PathoTec citrate test. It was concluded that the Enterotube system provides a simple, reliable, and rapid method for the presumptive identification of
Enterobacteriaceae
. The major advantage of the Enterotube is that all tests are done simultaneously by inoculation from a single isolated colony.
Quantitation of Microorganisms in Sputum
Authors: Monroe P. W. , Muchmore H. G. , Felton F. G. , Pirtle J. K.
Published: December 2020

A method of quantitating microbial cultures of homogenized sputum has been devised. Possible application of this method to the problem of determining the etiologic agent of lower-respiratory-tract infections has been studied to determine its usefulness as a guide in the management of these infections. Specimens were liquefied by using an equal volume of 2%
N
-acetyl-L-cysteine. The liquefied sputum suspension was serially diluted to 10
-1
, 10
-3
, 10
-5
, and 10
-7
. These dilutions were plated on appropriate media by using an 0.01-ml calibrated loop; they were incubated and examined by standard diagnostic methods. Quantitation of fresh sputum from patients with pneumonia prior to antimicrobial therapy revealed that probable pathogens were present in populations of 10
7
organisms/ml or greater. Normal oropharyngeal flora did not occur in these numbers before therapy. Comparison of microbial counts on fresh and aged sputum showed that it is necessary to use only fresh specimens, since multiplication or death alters both quantitative and qualitative findings. Proper collection and quantitative culturing of homogenized sputum provided information more directly applicable to patient management than did qualitative routine methods. Not only was the recognition of the probable pathogenic organism in pneumonia patients improved, but serial quantitative cultures were particularly useful in recognizing the emergence of superinfections and in evaluating the efficacy of antimicrobial therapy.
Analysis of the Diluents Used for Rubella Virus Hemagglutination and Hemagglutination-Inhibition Tests
Authors: Dold H. J. , Northrop R. L.
Published: December 2020

A new diluent (ADGP) for the rubella virus hemagglutination (HA) and hemagglutination-inhibition (HI) tests is described. It was found that the HA and HI titers and the erythrocyte agglutination pattern were improved in ADGP compared to previously described diluents. The influence of the components of ADGP and of various test conditions on optimal HA and HI results were examined.
Effects of Nitrogen Limitation on the Growth and Composition of Unicellular Algae in Continuous Culture
Authors: Richardson B. , Orcutt D. M. , Schwertner H. A. , Martinez Cara L. , Wickline Hazel E.
Published: December 2020

Since fat accumulation takes place in many algae as a response to exhaustion of the nitrogen supply, it has been suggested that this may provide a means of enhancing the potential food value of algae. To test this possibility, chemostatic continuous cultures of
Chlorella sorokiniana
and
Oocystis polymorpha
were subjected to successive reductions in influent nitrogen. As cellular nitrogen content decreased from about 10 to 4%, oxygen evolution, carbon dioxide uptake, chlorophyll content, and tissue production were drastically reduced, but total lipid content was essentially unchanged. Caloric values and C, H, and N analyses suggested a moderate increase in carbohydrate content, but gas chromatographic analyses revealed no significant qualitative or quantitative changes in the fatty acid fraction. In batch-cultured cells, nitrogen could be reduced to 3% of dry weight, causing a concomitant increase in total fatty acids and pronounced changes in the composition of the fatty acid fraction. These results suggest that cellular nitrogen must fall to approximately 3% of dry weight before appreciable increases in lipid synthesis can occur. Cell nitrogen is then apparently completely bound in essential cell constituents, and carbon subsequently fixed is converted into lipid products. The findings indicate that nitrogen limitation may be useful in increasing the food quality of batch-cultured cells, but the technique has little value for continuous culture systems per se.
Effect of Cultural Environment on the Blood Group Activity of Microorganisms
Authors: Moody Marcia R. , Young Viola M. , Faber John E.
Published: December 2020

Blood group activity was proven to be a property of the bacterium per se which possesses it, although such activity was influenced by the cultural environment of the organism. High concentrations of peptones having blood group activity were able to transfer this activity to inactive organisms; however, the conferred activity was proportional to the concentration. As a result of the low concentrations, the blood group activity of peptones was eliminated upon incorporation in culture media, and the activity of the peptones had no effect on the blood group activity levels of microorganisms when grown in these media. Conversely, the vitamin content of culture media did affect blood group active organisms. Multiple vitamins in media decreased the activity levels by blocking the reactive sites of the active organisms on which activity detection depended. Blood group activity levels were highest in media of minimal or no vitamin content. Therefore, it can be concluded that a choice of cultural medium becomes an important factor in the quantitation of bacterial blood group activity.
Simple Technique for Dark-Field Photography of Immunodiffusion Bands
Authors: Jensh Ronald P. , Brent Robert L.
Published: December 2020

A simple dark-field photographic technique was developed which enables laboratory personnel with minimal photographic training to easily record antigen-antibody patterns on immunodiffusion plates.
New
Salmonella
Serotype:
Salmonella enteritidis
ser. Ordonez
Authors: Bartes Sylvia F. , Martin W. J. , O'Connor P. E. , Marsden L. , Vogel H.
Published: December 2020

The antigenic formula of a new serotype,
Salmonella enteritidis
serotype Ordonez, was characterized as (
1
),
13,23,37:y:l,w
.
Resistance of
Pseudomonas
to Quaternary Ammonium Compounds. I. Growth in Benzalkonium Chloride Solution
Authors: Adair Frank W. , Geftic Sam G. , Gelzer Justus
Published: December 2020

Resistant cells of
Pseudomonas aeruginosa
and a waterborne
Pseudomonas
sp. (strain Z-R) were able to multiply in nitrogen-free minimal salts solution containing various concentrations of commercially prepared, ammonium acetate-buffered benzalkonium chloride (CBC), a potent antimicrobial agent. As the CBC concentration increased, growth increased until a point was reached at which the extent of growth leveled off or was completely depressed. Minimal salts solutions of pure benzalkonium chloride (PBC) containing no ammonium acetate did not support bacterial growth. When ammonium acetate was added to PBC solutions in the same concentrations found in CBC solutions, growth patterns developed that were comparable to those found with CBC. Likewise, (NH
4
)
2
SO
4
added to PBC solutions supported growth of both organisms.
P. aeruginosa
was initially resistant to CBC levels of 0.02% and it was adapted to tolerate levels as high as 0.36%. Strain Z-R was naturally resistant to 0.4% CBC. Since ammonium acetate, carried over by the CBC used in drug formulations and disinfectant solutions, has the potential to support the growth of resistant bacteria and thus make possible the risk of serious infection, it is suggested that regulations allowing the presence of ammonium acetate in CBC solution be reconsidered.
In Vitro Susceptibility of
Pseudomonas aeruginosa
to Carbenicillin and the Combination of Carbenicillin and Gentamicin
Authors: Phair John P. , Watanakunakorn Chatrchai , Bannister Thomas
Published: December 2020

One hundred and eleven strains of
Pseudomonas aeruginosa
isolated from clinical material were studied for susceptibility to carbenicillin. Of the strains, 80% were inhibited by 125 μg/ml or more. The combination of carbenicillin and gentamicin was shown to have inhibitory and bactericidal synergistic effect on 15 of 16 strains of
P. aeruginosa
tested. There was poor correlation between the single-disc sensitivity method and the tube dilution method.
Reactivity of Two Selected Antigens of
Neisseria gonorrhoeae
Authors: Reising Gilbert , Schmale John D. , Danielsson Dan G. , Thayer James D.
Published: December 2020

Two antigen preparations, the soluble antigen and a fraction 1 thereof, isolated in the course of a systematic study of the various antigens of the virulent gonococcus, have been investigated for their ability to serve as antigens for the detection of antibody in patients infected with the gonococcus. The soluble antigen was reactive with 88.2% of the sera from infected females, and fraction 1 was reactive with 71.6% of the sera. Of sera from infected males, only 27.6% reacted with the soluble antigen and only 20.4% with fraction 1. Of sera from individuals presumed free of gonococcal infection, approximately 4% reacted with the soluble antigen; none reacted with fraction 1. This study suggests that these antigens might be adaptable to the detection of human gonococcal antibody, especially in the female.
Automated, Quantitative Microhemagglutination Assay for
Treponema pallidum
Antibodies
Authors: Cox Patricia M. , Logan Leslie C. , Norins Leslie C.
Published: December 2020

An automated, quantitative microhemagglutination assay for antibodies to
Treponema pallidum
was developed by using
T. pallidum
-sensitized erythrocytes and an automatic serial-dilution instrument. Reactivity was found in sera from 54 rabbits and 6 chimpanzees infected with
T. pallidum.
Reactivity was also found in sera from animals infected with
T. pertenue, T. carateum
, and
T. cuniculi
. No reactivity was found in sera from 75 normal rabbits or from 129 rabbits immunized with cultivatable treponemes or a variety of other bacteria. In approximately 3 min, 13 twofold serial dilutions of each of 8 preabsorbed sera and the addition of sensitized erythrocytes to each dilution were accomplished automatically. The automated assay can serve as a research tool in quantitating antibodies to pathogenic treponemes, and evaluation of its clinical usefulness seems warranted.
Antiviral Effect of Cyclic Amines on a 1969 Isolate of A
2
Influenza
Authors: Greene J. F. , Tilton B. E. , Quilligan J. J.
Published: December 2020

Cyclooctylamine and amantadine inhibit the growth of 1969 isolates of A
2
influenza virus to a significant degree. There was slightly more inhibition of the virus by the cyclooctylamine (COA) than the amantadine; however, the dose of COA used was greater than the dose of amantadine. There was no significant difference between flasks treated 3 or 4 hr and those treated 2 hr. However, there was a curious relationship of more plaques in the flasks exposed to the two drugs for the longer intervals. Other experiments done with slight modifications in technique support the antiviral effect demonstrated in this experiment when the cell system is pretreated prior to virus infection. In two experiments, pretreating the cells for 2 hr with COA at 100 μg/ml but removing the drug solution and washing the cells prior to virus inoculation revealed no differences in plaque counts between controls and treated cells. This would indicate that the antiviral effect required the presence of the drug during the early stages of penetration of the cells by the virus particles.
Occurrence of False-Positive Most Probable Number Tests for Fecal Streptococci in Marine Waters
Authors: Buck John D.
Published: December 2020

By the use of the most probable number technique with azide dextrose and ethyl violet azide broths for enterococci, the common occurrence of false-positive tests was noted when marine and estuarine waters were sampled. Organisms isolated included a marine bacterium, gram-positive and gram-negative nonmarine bacteria, and yeasts. All cultures were capable of growth in azide-dextrose, ethyl violet-azide, and KF broths. Representative isolates grew in media containing 0.08% NaN
3
. The tentatively accepted most probable number method for fecal streptococci is thus of dubious value in assessment of sewage pollution levels in estuarine waters. All positive tubes must be examined microscopically for the presence of nonstreptococcal forms.
Radiation Sterilization of Prototype Military Foods. III. Pork Loin
Authors: Anellis Abe , Berkowitz D. , Jarboe C. , El-Bisi H. M.
Published: December 2020

Ten lots of pork loin, packed in cans, were inoculated with approximately 10
6
Clostridium botulinum
spores per can. Each lot was seeded with a different strain; five type A and five type B strains were used. The pack comprised 5,690 cans, including controls, and contained about 10
9
spores per dose. The cans were irradiated with Co
60
in the range of 0 to 5.0 Mrad (0.5 Mrad increments) at 5 to 25 C, incubated for 6 months at 30 C, and examined for swelling, toxicity, and recoverable
C. botulinum
. The minimal experimental sterilizing dose (ESD) based on nonswollen, nontoxic, but nonsterile end points was 2.5 < ESD ≤ 3.0 Mrad, and based on non-spoiled sterile cans was 3.5 < ESD ≤ 4.0 Mrad. The theoretical minimal radiation dose (MRD), the 12
D
equivalent, varied with the method of computation: 4.74, 4.33 � 0.17, and 4.19 to 4.99 Mrad were obtained by the Weibull, Spearman-B�rber, and Schmidt-Nank techniques, respectively. Calculation of
D
and MRD values by the conventional Schmidt-Nank method produced increasing values with rising dosage; this finding was compared with the data derived by the other two methods of calculation. Suggestions for estimating the MRD of a prototype radiation process are offered.
Application of Paraffin Bait Technique to the Isolation of
Nocardia asteroides
from Clinical Specimens
Authors: Mishra S. K. , Randhawa H. S.
Published: December 2020

The principal findings of a study for further evaluating paraffin baiting as a routine laboratory diagnostic procedure in the isolation of
Nocardia asteroides
, the etiological agent of nocardiosis, are reported.
Some Pink Yeasts Associated with Softening of Olives
Authors: Vaughn Reese H. , Jakubczyk Tadeusz , MacMillan James D. , Higgins Thomas E. , Davé Bhalchandra A. , Crampton Veronica M.
Published: December 2020

Pink yeasts identified as
Rhodotorula glutinis
var.
glutinis, R. minuta
var.
minuta
, and
R. rubra
produce polygalacturonases which cause a slow softening of olive tissue. Both pectin methyl esterase and polygalacturonase are produced when cultures are grown in appropriate media. Crude, cell-free dialyzed enzyme preparations measured viscosimetrically exhibited optimal activity on sodium polygalacturonate at
p
H 6.0 and 40 C, and were active in the range of
p
H 4.0 to 9.0 and 10 to 50 C. Cultures grown in sterilized olives and brine at
p
H 4.0 with sterile glucose added aseptically caused a slow softening of tissue as measured with a Christel texturometer. Similar results were obtained when crude, cell-free enzyme preparations were added to olives in buffer solution at
p
H 6.0 with Merthiolate. Commercial control of these yeasts is easy if anaerobic conditions can be provided. Otherwise, the industry has to resort to manual removal of the film from the brine surface, either by skimming or by flagellation.
Control Mechanisms Operative in a Natural Microbial Population Selected for Its Ability to Degrade L-Lysine. II. Effects of Fructose and Ribose in Batch Systems
Authors: Grady C. P. L. , Gaudy A. F.
Published: December 2020

A natural microbial population was acclimated to L-lysine as the sole carbon source when ammonia nitrogen was provided in the medium. Fructose exerted a slight retarding effect upon the metabolic removal of lysine. The response was due to catabolite repression of the inducible enzyme system responsible for lysine degradation. Inhibition of activity of preformed enzymes played no part in the response. Ribose caused a slight increase in the rate of synthesis of lysine-degrading enzymes.
Standardized Viral Hemagglutination and Hemagglutination-Inhibition Tests. II. Description and Statistical Evaluation
Authors: Hierholzer John C. , Suggs Morris T. , Hall Elmer C.
Published: December 2020

Standardized hemagglutination and hemagglutination-inhibition procedures are described and statistically evaluated for all animal viruses where applicable, except for rubella and the arbovirus group. The standardized tests employ a constant phosphate-buffered saline diluent and constant volumes of serum, antigen, and standardized erythrocyte suspension. The standardized hemagglutination test has a reproducibility of 84 to 96% with adenoviruses, rubeola, and the myxoviruses, and 78 to 93% with reoviruses; the standardized hemagglutination-inhibition test has a reproducibility of 95 to 100% with all viruses tested.
Simplified Method for the Production of Carbohydrate Antigen from
Neisseria meningitidis
Authors: Weiss Emilio , Long James L.
Published: December 2020

The Gotschlich procedure for the production of carbohydrate antigens from the supernatant fluids of cultures of
Neisseria meningitidis
groups A and C was modified. Steps involving digestion with nucleases and gel filtration through Sephadex G-50 were added, the number of extractions was greatly reduced, and high-speed centrifugations were eliminated. The antigens thus obtained appeared to be entirely comparable to those described by Gotschlich et al. in physical, chemical, and antigenic properties. A slight degree of protection of mice was repeatedly demonstrated with extraordinarily large doses of antigen (50 μg/mouse), but not with smaller doses. Toxicity of the antigens for laboratory animals was very slight.
Effect of Prehumidification on Sampling of Selected Airborne Viruses
Authors: Warren J. C. , Akers T. G. , Dubovi E. J.
Published: December 2020

Studies were undertaken to determine if a prewetting device (humidifier bulb) used in combination with an all glass impinger (AGI-30) would increase the recovery of airborne mengovirus-37A, vesicular stomatitis virus (VSV), and the S-13 coliphage. Suspensions of T3 coliphage with mengovirus-37A, VSV, or S-13 were aerosolized and collected by using the AGI-30-humidifier bulb combination to sample the aerosols before and after shifts in relative humidities (RH). These studies revealed the following. (i) At low RH values there was a 3 to 4 log increase in recovery of airborne T3 phage; (ii) concomitantly, the recovery of mengovirus-37A and VSV decreased; and (iii) only at the mid-range RH values was the recovery of S-13 enhanced. The prehumidification technique significantly increased the recovery of airborne T3 phage but decreased the recovery of the two animal viruses tested.
Survival of
Salmonella montevideo
on Wheat Stored at Constant Relative Humidity
Authors: Crumrine Martin H. , Foltz Vernon D.
Published: December 2020

Eleven samples of Ottawa variety hard red winter wheat were inoculated with a standardized suspension of
Salmonella montevideo
. The contaminated wheat samples were placed in constant relative humidity (RH) chambers held at 25 C. Relative humidities were 7, 11, 22, 33, 43, 53, 62, 75, 84, 92, and 98%. Constant RH at 25 C was maintained with different saturated salt solutions in the sealed chambers. Periodic counts of viable
S. montevideo
cells per gram of wheat were made over a 28-week sampling period. Viable counts of
S. montevideo
on wheat held at 7, 11, and 22% RH decreased from an initial 10
6
cells/g of wheat to a final count of 10
4
cells/g in each sample. Samples stored at 33, 43, 53, and 62% RH decreased from 10
6
viable cells/g to 3.6 × 10
3
, 10
3
, 10
2
, and 20 viable cells/g, respectively. No viable
S. montevideo
cells were detected in the samples held at 75, 84, 92, and 98% RH after 22, 16, 26, and 16 weeks, respectively.
Evaluation of Thallium Acetate-Citrate Medium for Isolation of Enterococci
Authors: Bulich Anthony A. , Hartman Paul A.
Published: December 2020

Thallous acetate-citrate (TAC) agar, a selective medium for isolating enterococci from frozen foods, was evaluated. Two types of bacteria, micrococci and group N streptococci, were responsible for erroneously high enterococcus counts on TAC agar. Selectivity of the medium was improved by the addition of 0.01% sodium azide.
Concentration of Viruses from Sewage and Excreta on Insoluble Polyelectrolytes
Authors: Wallis Craig , Grinstein Saul , Melnick Joseph L. , Fields Joseph E.
Published: December 2020

The concentration of viruses from sewage by adsorption on and elution from an insoluble cross-linked copolymer of maleic anhydride is described. Viruses either added to sewage or naturally contained in sewage were preferentially adsorbed to this polyelectrolyte at a
p
H range of 5.0 to 6.0 and were eluted at
p
H 8.0 to 9.0. In a 2-month survey of viruses in sewage in the spring (April to May 1968), when viruses are at low levels, efficient and economical detection of these agents was accomplished with the polyelectrolyte-concentration method. This method lends itself to the detection of viruses present in minute amounts in fecal samples, urine, sewage, and other natural waters. Large volumes of these fluids can be treated with the polymer described, and virus can be concentrated sufficiently for detection.
Numerical Taxonomy of Heterotrophic Bacteria Growing in Association with Continuous-Culture
Chlorella sorokiniana
Authors: Litchfield Carol D. , Colwell Rita R. , Prescott J. M.
Published: December 2020

Twenty-nine cultures isolated from nonaxenic growths of
Chlorella sorokiniana
(Shihira and Krauss) and eight reference cultures were tested for 150 morphological and biochemical characteristics. The taxonomic data were subjected to computer analysis from which five major clusters were identified. The bacterial isolates have been placed in the genera:
Pseudomonas, Acinetobacter, Flavobacterium
, and
Bacillus
. Amino acid requirements of four strains from the test set were determined.
Antimicrobial Activity of Some
N
-Substituted Amides of Long-Chain Fatty Acids
Authors: Novak Arthur F. , Solar James M. , Mod Robert R. , Magne Frank C. , Skau Evald L.
Published: December 2020

Seventy-three
N,N
-disubstituted amides of long-chain, principally C
18
, fatty acids were screened for antimicrobial activity against bacteria, yeasts, and molds. Amides containing an epoxy group exhibit a broad spectrum of antimicrobial activity which is further enhanced by unsaturation. Mono-unsaturation alone does not contribute a broad level of activity to the
N,N
-disubstituted amides of the C
18
fatty acids.
Separation of Cell Types of
Vibrio fetus
Authors: Marsh David H. , Kluses Elmer S. , Ogg James E.
Published: December 2020

Separation of the coccoid form of
Vibrio fetus
from cultures containing both the coccoid and vibrioid cell types has been accomplished using rate-zonal centrifugation.
Utilization of Methylthio-
s
-Triazine for Growth of Soil Fungi
Authors: Murray Don S. , Rieck Walter L. , Lynd J. Q.
Published: December 2020

Aspergillus niger
van Tieghem,
Aspergillus tamarii
Kita, and
Aspergillus flavus
Link ex Fries utilized the methylthio moiety of 2,4-bis(isopropylamino) -6-methyl-mercapto-
s
-triazine (prometryne) as a sulfur nutrient source. Other soil fungal isolates not affected by prometryne concentrations to 1 mg/ml culture included:
Aspergillus oryzae
(Ahlburg) Cohn,
Curvularia lunata
(Wakker) Boedijn,
Trichoderma viride
Persoon ex Fries,
Alternaria tenuis
Nees ex Corda,
Penicillium funiculosum
Thom, and
Paecilomyces varioti
Bainier.
Device for Ensuring Continuity of Air Supplied to Carbon Dioxide Incubators for Tissue Culture
Authors: Kreider John W.
Published: December 2020

A simple device to ensure the continuity of air supplied to carbon dioxide incubators for tissue cultures is described.
Effects of Hypobaric and Hyperbaric Helium Atmospheres on the Growth of
Chlorella sorokiniana
Authors: Orcutt D. M. , Richardson B. , Holden R. D.
Published: December 2020

Growth of
Chlorella sorokiniana
is unaffected by the choice of atmospheric diluent gas. Reduced total pressure has no inhibitory effect and may be slightly stimulatory.
Laboratory Identification of
Torulopsis glabrata:
Typical Appearance on Routine Bacteriological Media
Authors: Marks Melvin I. , O'Toole Elizabeth
Published: December 2020

The colonial morphology of the yeast
Torulopsis glabrata
on sheep blood-agar is characteristic and was useful in the identification of 24% of clinical isolates.
Measurement of
14
CO
2
Assimilation in Soils: an Experiment for the Biological Exploration of Mars
Authors: Hubbard Jerry S. , Hobby George L. , Horowitz Norman H. , Geiger Paul J. , Morelli Frank A.
Published: December 2020

A method is described for the measurement of
14
CO
2
assimilation by microorganisms in soils. A determination involves exposing soil to
14
CO
2
, pyrolyzing the exposed soil, trapping the organic pyrolysis products on a column of firebrick coated with CuO, combusting the trapped organics by heating, and measuring the radioactivity in the CO
2
produced in the combustion. The detection of significant levels of
14
C in the trapped organic fraction appears to be an unambiguous indication of biological activity. The
14
CO
2
which is adsorbed or exchanged into soils by nonbiological processes does not interfere. The method easily detects the
14
CO
2
fixed by 10
2
to 10
3
algae after light exposure for 3 to 24 hr. Assimilation of
14
C is also demonstrable in dark-exposed soils containing 10
5
to 10
6
heterotrophic bacteria. Possible applications of the method in the biological exploration of Mars are discussed.
Response of Airborne
Mycoplasma pneumoniae
to Abrupt Changes in Relative Humidity
Authors: Hatch M. T. , Wright D. N. , Bailey G. D.
Published: December 2020

The effect of an abrupt change in the relative humidity on the viability of airborne
Mycoplasma pneumoniae
has been examined. When the microbial aerosols were permitted to equilibrate in air held at either low or high humidities and were then subjected to a sudden shift to a mid-range humidity, a significant loss (>90%) of the colony-forming units per liter of aerosol occurred within 8 min. In contrast, a change in the relative humidity of more than 18% in either direction from a lethal mid-range humidity noticeably decreased the rate of biological decay. Double humidity shifts (i.e., from dry to a mid-range level and then to a high humidity range) were very detrimental, with very few survivors after 8 min. These results indicate that the biological stability of airborne
M. pneumoniae
may be easily modified by a sudden change in the relative humidity, such as occurs in natural atmospheres. This increased sensitivity brought about by producing changes in relative humidity through the lethal humidity range may provide a method whereby the control of these organisms in naturally contaminated indoor air environments may be eventually achieved.
Relationship Between Atmospheric Temperature and Survival of Airborne Bacteria
Authors: Ehrlich Richard , Miller Sol , Walker Robert L.
Published: December 2020

Effects of temperatures ranging from −40 to 49 C on the behavior of airborne
Serratia marcescens, Escherichia coli
, and
Bacillus subtilis
var.
niger
were investigated. Aerosol decay rates of
B. subtilis
spores were not significantly affected by the temperature and remained approximately constant within the temperature range studied. The survival of airborne
S. marcescens
and
E. coli
was closely related to the temperature. An increase in temperature from −18 to 49 C resulted in a progressive increase of the biological death rate, and the relationship between the biological death rate and the temperature appeared to be linear. An increase in temperature from 24 to 49 C resulted in significantly reduced aerosol recoveries of the two vegetative organisms. At −40 C, the aerosol recovery of all three agents was consistently lower than at −18 to 24 C.
Agglutinin Response of Rabbits to Combined
Pasteurella tularensis-Brucella abortus
Vaccination
Authors: Nutter John E.
Published: December 2020

A schedule was developed for the simultaneous production of a
Pasteurella tularensis-Brucella abortus
antiserum in rabbits. Three doses of 10
8
viable
P. tularensis
LVS organisms were given intravenously at weekly intervals. One day prior to the final dose of
P. tularensis
, the rabbits received 10
9
viable cells of
B. abortus
strain 19 intravenously. The use of live vaccines, administered in this sequence, resulted in high agglutinin titers within 3 weeks. The maximal agglutinin titer to either organism was observed 1 week after the final injection.
Comparison of a Blood Culture System Containing Liquoid and Sucrose with Systems Containing Either Reagent Alone
Authors: Rosner Richard
Published: December 2020

By utilizing parallel culture methods on multiple blood specimens, three blood culture systems were evaluated for their ability to allow rapid recovery of organisms. The same base medium was used for all three systems. System or flask 1 contained base medium with Liquoid added, flask 2 contained base medium with sucrose added, and flask 3 contained both Liquoid and sucrose. During the study period, there were 259 patients considered to have positive blood cultures. Organism recovery was accomplished from flask 1 in 214 of these patients, from flask 2 in 180 cases, and from flask 3 in 257 instances. The use of anticoagulants and osmotic stabilizers in blood culture systems is discussed in detail.
Colorimetric Assay for Lysine Decarboxylase in
Escherichia coli
Authors: Lu Wanda W.-W. , Mallette M. F.
Published: December 2020

A new assay is described for lysine decarboxylase. It is rapid and reproducible in assaying large numbers of samples, a situation in which earlier methods were less convenient. The new method is valuable in the study of peptide fractions and amino acid mixtures which stimulate induction of lysine decarboxylase. It may be useful for work on enzyme structure and modification, genetics, and kinetics.
Antifungal Activity of Alkylxylylene-Bis-Isothiuronium Chlorides
Authors: Shelley Gail , Huisingh D. , Hamilton P. B.
Published: December 2020

Low concentrations of dodecylxylylene-bis-isothiuronium chloride, synthesized from an inexpensive detergent intermediate, inhibited members of 21 genera of fungi.
Comparison of Media for Direct Isolation and Transport of Shigellae from Fecal Specimens
Authors: Morris George K. , Koehler Judith A. , Gangarosa Eugene J. , Sharrar Robert G.
Published: December 2020

Xylose-lysine-deoxycholate (XLD) agar, SS agar, and MacConkey agar for isolating shigellae from fecal specimens were compared. XLD agar was superior to both SS agar and MacConkey agar for isolating
Shigella sonnei
, and both XLD and SS agar were superior to MacConkey agar for isolating
S. flexneri
. Direct plating of the fecal specimens in the field resulted in a greater yield of shigellae as compared to transporting specimens to the laboratory either in holding media or enrichment broth. Buffered glycerol saline was superior to other transport media evaluated, yielding 83% of shigella isolates when plated within 48 hr as compared to direct plating. The combination of XLD agar and SS agar is recommended for direct isolation of shigellae, and, whenever possible, these solid media should be taken to the bedside and inoculated directly.
Ten-Minute Test for Differentiating Between
Klebsiella
and
Enterobacter
Isolates
Authors: Matsen John M.
Published: December 2020

A 10-minute test, utilizing a urease paper-reagent strip (PATHO-TEC), for differentiating
Klebsiella
and
Enterobacter
species is described. By using a heavy suspension of organisms and 50 C temperature for incubation, 93% of
Klebsiella
strains (186/200) were positive and 95% of
Enterobacter
strains (190/200) were negative with this testing system. The rapid nature of the test (10 min), the facility with which it can be carried out, and the ease with which the strips can be stored and handled may make this a useful aid for the clinical microbiologist.
Evaluation of a New Incubation-Type Indole Strip Test
Authors: Blazevic Donna J. , Ederer Grace Mary , Matsen John M.
Published: December 2020

A total of 189 of
Enterobacteriaceae
and three strains of
Clostridium perfringens
were tested with a new incubation-type indole paper strip. This 4-hr incubation test gave the same results as a standard 48-hr indole test, except with some strains of
Proteus rettgeri
. Results with
P. rettgeri
varied somewhat according to the medium upon which the organisms had been grown.
Continuous Monitoring of Oxygen Concentrations in Air-Purged Shake-Flask Fermentations
Authors: Hodson Phillip H.
Published: December 2020

Continuous monitoring of the oxygen concentrations in the gas and liquid phases in air-purged shake-flask fermentations was accomplished by means of steam-sterilizable oxygen probes.
Arbovirus Identification by an Agar-Gel Diffusion Technique
Authors: Calisher C. H. , Maness K. S. C.
Published: December 2020

A double diffusion-in-agar test was used to investigate precipitation reactions of 75 arboviruses. Specific reactions were regularly observed with members of arbovirus groups B, California, Simbu, Turlock, Hart Park, vesicular stomatitis, and several other arboviruses as well as with a member of the Tacaribe group and a herpesvirus. The results demonstrated the feasibility of applying this technique to the identification of arboviruses.
Formation of Hydrogen Peroxide by Group N Streptococci and Its Effect on Their Growth and Metabolism
Authors: Anders R. F. , Hogg D. M. , Jago G. R.
Published: December 2020

The formation of hydrogen peroxide by group N streptococci was found to occur through the action of a reduced nicotinamide adenine dinucleotide (NADH) oxidase which catalyzed the oxidation of NADH by molecular oxygen. The enzyme was activated by flavine adenine dinucleotide. Whereas some of the hydrogen peroxide formed was removed through the action of an NADH peroxidase, sufficient accumulated in media to inhibit the growth, respiration, and viability of these organisms. The amount of hydrogen peroxide which accumulated varied among strains, and this variation could be related to differences in the properties of the NADH oxidase present.
Nitrogen Requirements and Uricolytic Activity of Cutaneous Bacteria
Authors: Smith Rodney F.
Published: December 2020

Uric acid, but not xanthine, was degraded by gram-positive catalase-producing cocci and diphtheroids which represented the two predominant human autochthonous skin bacteria. The proportions of uricolytic cocci and diphtheroids varied with the cutaneous site sampled. Uric acid and allantoin were not utilized by cocci or diphtheroids as sole sources of nitrogen. Uric acid appeared to act only as a secondary substrate for the gram-positive bacteria. Cutaneous cocci are known to be ureolytic but few diphtheroids had urease activity. Urea and ammonium nitrogen were not utilized as sole nitrogen sources by cocci, but some diphtheroids used these compounds for nitrogen. The majority of the cocci and diphtheroids were nutritionally fastidious and required amino-nitrogen for growth. In addition, some strains required vitamins and other unidentified metabolites found in yeast extract. These requirements were partially related to the cutaneous site from which the cocci or diphtheroids were isolated. Certain gram-negative bacilli degraded uric acid and utilized urate or its degradation products as nitrogen sources.
Enzymatic Removal of Diacetyl from Beer
Authors: Tolls T. N. , Shovers J. , Sandine W. E. , Elliker P. R.
Published: December 2020

Diacetyl removal from beer was studied with whole cells and crude enzyme extracts of yeasts and bacteria. Cells of
Streptococcus diacetilactis
18-16 destroyed diacetyl in solutions at a rate almost equal to that achieved by the addition of whole yeast cells. Yeast cells impregnated in a diatomaceous earth filter bed removed all diacetyl from solutions percolated through the bed. Undialyzed crude enzyme extracts from yeast cells removed diacetyl very slowly from beer at its normal
p
H (4.1); at a
p
H of 5.0 or higher, rapid diacetyl removal was achieved. Dialyzed crude enzyme extracts from yeast cells were found to destroy diacetyl in a manner quite similar to that of diacetyl reductase from
Aerobacter aerogenes
, and both the bacterial and the yeast extracts were stimulated significantly by the addition of reduced nicotinamide adenine dinucleotide (NADH). Diacetyl reductase activity of four strains of
A. aerogenes
was compared; three of the strains produced enzyme with approximately twice the specific activity of the other strain (8724). Gel electrophoresis results indicated that at least three different NADH-oxidizing enzymes were present in crude extracts of diacetyl reductase. Sephadex-gel chromotography separated NADH oxidase from diacetyl reductase. It was also noted that ethyl alcohol concentrations approximately equivalent to those found in beer were quite inhibitory to diacetyl reductase.
Large-Quantity Production of Chicken Embryo Tracheal Organ Cultures and Use in Virus and Mycoplasma Studies
Authors: Cherry J. D. , Taylor-Robinson D.
Published: December 2020

Chicken tracheal organ cultures were made from embryos which were 19 to 20 days old. Transversely cut rings of trachea were placed in screw-capped tissue-culture tubes with Eagle's-
N
-2-hydroxyethylpiperazine-
N′
-2-ethanesulfonic acid (HEPES) medium and incubated in roller drums. The method had advantages over other organ culture systems in that these cultures were prepared in numbers similar to conventional tissue cultures, ciliary activity was quickly and accurately evaluated, and contamination occurred less frequently than with organ cultures in petri dishes. Ciliary activity persisted for at least 1 month when the medium was changed at 5-to 7-day intervals and for 10 to 15 days without a change. Infectious bronchitis virus stopped ciliary movement, and this effect was used as a basis for titrating the virus and for determining the neutralizing capacity of immune mouse ascitic fluid. Twenty-four
Mycoplasma
strains were tested. Organisms of 17 strains, both avian and mammalian, multiplied in the organ cultures, and 7 strains, belonging to the species
M. gallisepticum
and
M. mycoides
var.
capri
, inhibited ciliary activity.
Virus Particle Content of Smallpox Vaccines
Authors: Dunlap R. C.
Published: December 2020

Calf lymph smallpox vaccines contain too much extraneous debris for an accurate assessment of their virus particle content. The process of partial purification of the vaccine utilizing enzymatic digestion by chymotrypsin, subtilisin, and collagenase solubilized enough debris to permit electron microscopic virus particle count. Enzyme treatment did not degrade or destroy the virus nor did it reduce the infective titer. Commercial vaccines studied ranged in virus content from 1.89 × 10
9
to 1.09 × 10
11
virus particles/ml. The pocking efficiencies on the chorioallantoic membrane of some of these vaccines varied from 200 to 1,200 virus particles per pock-forming unit.
Salmonella enteritidis
Serotype 50
1, 2, 3
: z
4
, z
24
: -
Authors: Ball Mary M. , Martin William Jeffrey , Kourany Miguel , Telford Sam R.
Published: December 2020

Characteristics of a new
Salmonella
serotype, subgenus IV, are reported. Culture 5534-68 was recovered from the intestinal tract of
Anolis biporcatus
, an arboreal lizard found in deep forest tracts in Panama Province, Republic of Panama. The antigenic composition of this new serotype was found to be 50
1, 2, 3
:z
4
, z
24
:-.
Changes in the Differential Leukocyte Count of Chicks Inoculated with
Salmonella
Authors: Anderson E. L. , Stephens J. F.
Published: December 2020

Studies were conducted to determine the effects of
Salmonella anatum
and
S. heidelberg
infections on the differential leukocyte counts of baby chickens. Newly hatched broiler-type chicks were inoculated in the yolk sac with suspensions of either
S. anatum
or
S. heidelberg.
At 0, 24, 48, and 72 hr after inoculation, blood was taken by heart puncture from chicks of both inoculated groups and from a group of uninoculated chicks. The averages of the leukocyte counts of three or four chicks from each group were used as the blood values for specific time intervals. The six classes of leukocytes counted were lymphocytes, monocytes, juveniles, heterophils, eosinophils, and basophils. The leukocytes classified as juveniles were immature or degenerate heterophils and were found almost exclusively in the infected chicks. Changes in heterophil, juvenile, and lymphocyte counts were affected by both the number of cells in the inoculum (300 versus 3 million cells of
S. anatum
) and species (
S. anatum
and
S. heidelberg
). Infection with either
Salmonella
species resulted in the development of a severe heterophilic leukopenia, and a significant increase in the percentage of both juveniles and lymphocytes by 48 hr postinoculation. Mortality rate was higher in groups of chicks inoculated with
S. heidelberg
than in groups given
S. anatum.
Somatic Antigens of
Streptococcus
Group E
Authors: Payne Jerry B. , Armstrong Charles H.
Published: December 2020

Eleven
Streptococcus
group E strains, representing serotypes I, II, III, IV, V, and “untypable” isolates, were extracted by formamide, trichloroacetic acid, and hydrochloric acid under various conditions in an effort to determine the best method for recovering maximum amounts of group and type antigens. The group antigen was found to be relatively stable, and adequate amounts for identification purposes were recovered by a wide spectrum of conditions. Type-specific antigens were relatively labile, and were destroyed at low
p
H in acid hydrolysis or by prolonged heating in formamide hydrolysis. The best single procedure for recovering both type and group antigens from
Streptococcus
group E was formamide hydrolysis for 30 min at 180 C.
Black Beauty Out of
Mycobacterium fortuitum
Cruz
Authors: Gordon Ruth E. , Pang C. Hor-Nay
Published: December 2020

A black-pigmented strain developed spontaneously from a typical strain of
Mycobacterium fortuitum.
Low Antibiotic Potency of Isohumulone
Authors: Teuber Michael
Published: December 2020

Isohumulone is 15 to 30 times less inhibitory than lupulone or humulone on the growth of gram-positive bacteria.
Construction of a Laboratory Press for Use with the French Pressure Cell
Authors: Vanderheiden G. J. , Fairchild A. C. , Jago G. R.
Published: December 2020

A motor-driven hydraulic press has been designed to overcome problems previously encountered with the use of the French pressure cell.
Variation in Composition of Yeast Phosphohexosans
Authors: Slodki M. E. , Safranski M. J. , Hensley D. E. , Babcock G. E.
Published: December 2020

Omitting of KH
2
PO
4
from culture media leads to the production of altered phosphohexosans or neutral extracellular mannans by yeasts that otherwise elaborate phosphogalactans and phosphomannans.