bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation of
Eikenella corrodens
in a General Hospital
Authors: Zinner Stephen H. , Daly A. Kathleen , McCormack William M.
Published: December 2020

Eikenella corrodens
is a small pleomorphic gram-negative bacillus which produces pitting on agar. From December 19, 1970, to December 2, 1971,
E. corrodens
(also known as HBI) was isolated from material submitted to the Diagnostic Bacteriology Laboratory of the Boston City Hospital from 72 patients (48 males, 24 females) ranging in age from 8 months to 92 years. The organism was recovered from sputum or bronchial washings in 46 instances, from throat or nasopharyngeal swabs in 11, from wounds in 8, from 2 human bites, and from 3 abscesses. It was isolated in pure culture from one of the human bites. Antibiotic susceptibility was measured for 26 strains against six antibiotics by using the inocula replicating method on heart infusion blood agar.
E. corrodens
was most susceptible to penicillin and ampicillin with 100% and 96% of strains inhibited by 1.65 μg of these antibiotics per ml, respectively. Eighty percent of the strains were inhibited by 3.125 μg of chloramphenicol per ml and 52% were inhibited by this amount of gentamicin. Resistance was greater for tetracycline and clindamycin.
Micromethod System for Identification of Anaerobic Bacteria
Authors: Starr S. E. , Thompson F. S. , Dowell V. R. , Balows A.
Published: December 2020

A micromethod multitest system prepared by Analytab Products, Inc. and conventional tests employed at the Center for Disease Control for identification of anaerobes were compared. All procedures were conducted in an anaerobic glove box. A total of 104 cultures, including 18 reference strains and 86 diagnostic cultures, were examined. Ninety-one percent of the total tests performed with the two systems were in agreement. Greater than 90% agreement between the two systems was obtained with 12 of the 17 differential tests compared. The tests for nitrate reduction and H
2
S production gave the poorest agreement, 77.8 and 80.8%, respectively. Only 66% of the 86 diagnostic cultures could be presumptively identified with the micromethod system supplemented only with microscopy and colonial characteristics. However, when appropriate supplementary tests and gas-liquid chromatography were used with the micromethod system, 85% of the 86 strains could be identified. When Ehrlich reagent, instead of Kovac reagent, was used with the micromethod to test for indole, the agreement in identification was raised to 93%.
Automation of the Indirect Fluorescent-Antibody Test for Toxoplasmosis
Authors: Kaufman G. I. , Remington J. S. , Waters H. C.
Published: December 2020

The feasibility of automating the decision-making tasks of the medical technician in the determination of the results of the indirect fluorescent-antibody test for toxoplasmosis was investigated. Two approaches were studied: (i) macroscopic measurement of fluorescence from a large number of organisms (full-field illumination measurements), and (ii) microscopic measurements of fluorescence and morphology of individual parasites (pattern recognition). The macroscopic approach was studied utilizing an argon-ion laser in incident illumination with a Leitz Ortholux microscope and a phototube mounted so as to measure green fluorescence. Due to similar amounts of fluorescence from negative polar reactions and positive rim reactions, the macroscopic technique was concluded to be not feasible. The microscopic approach was studied utilizing a high resolution optical pattern recognition instrument. The results indicate that an object area measurement is sufficient to distinguish the presence of
Toxoplasma gondii
organisms from debris and overlapping organisms when studying the red fluorescence (due to Evans blue counterstain). Dark reactions were determined by the absence of green fluorescence. The differentiation of the rim and polar reactions was determined by the measurement of the ratio of green fluorescing area (due to fluorescein isothiocyanate) to red fluorescing area on the same organism. Clinically important titer information was also demonstrated to be obtainable. It was concluded that complete automation of the indirect fluorescent antibody test for toxoplasmosis is feasible with existing technology.
Isolation of Salmonellae from Pork Carcasses
Authors: Carpenter J. A. , Elliot J. G. , Reynolds A. E.
Published: December 2020

Four hundred and twenty pork carcasses from four abattoirs were examined for the presence of salmonellae by use of swabbing-enrichment techniques and contact plate methods. Carcasses from only one abattoir were found to be contaminated by swabbing-enrichment (23.3%) and contact plate (17.9%) methods. The area of the skin side of the ham, near the anal opening, was determined to be the area to examine for isolating salmonellae from pork carcasses with the greatest frequency. The most frequently isolated species of salmonellae in this study were
Salmonella derby, S. anatum, S. typhimurium
, and
S. indiana
.
Bactericidal Effect of Various Combinations of Gamma Radiation and Chloramine on Aqueous Suspensions of
Escherichia coli
Authors: Venosa Albert D. , Chambers Cecil W.
Published: December 2020

Methods of combining gamma radiation with chloramine to disinfect aqueous suspensions of
Escherichia coli
were investigated. Logarithmically grown cells were exposed to the bactericidal agents sequentially (i.e., radiation followed by chloramine, and chloramine followed by radiation) and simultaneously. Regardless of which combination was used, the bactericidal effect was always less than additive. During the phase of work involving the simultaneous addition of both agents, it was observed that chloramine was destroyed more rapidly by radiation than were the organisms. Since an increase in the bactericidal effectiveness of either disinfectant by prior or simultaneous treatment of the cells with the other disinfectant was not achieved in buffered distilled water, it was concluded that disinfection of wastewater effluents by combining ionizing radiation with chloramine would not be economically feasible.
Tissue Distribution and Metabolism of Aflatoxin B
1
-
14
C in Broiler Chickens
Authors: Mabee Michael S. , Chipley John R.
Published: December 2020

The effects of administering low levels of aflatoxin B
1
-
14
C by crop intubation daily for 14 days to broiler chickens were determined. Studies on the distribution of
14
C in the blood, selected organs, tissues, and excreta were conducted. No toxic effects were observed in broiler chickens during the 14 days of the experiment. The broiler chickens excreted 90.64% of the
14
C administered. Of the
14
C retained, 11.04, 9.83, 4.30, 12.52, 31.66, and 30.63% were detected in the blood, liver, heart, gizzard, breast, and leg, respectively. Chemical assay of those samples demonstrating radioactivity revealed that 81.2% of the radioactivity in these substrates was not extractable by classical extraction procedures while approximately 10% was extractable. Treatment of aqueous extracts for conjugated steroids by treatments with beta-glucuronidase revealed that 31.5% of the
14
C detected in the aqueous extract was a liberated glucuronide conjugate of aflatoxin M
1
-
14
C.
Staphylococcus aureus
Enterotoxin B Release (Excretion) Under Controlled Conditions of Fermentation
Authors: Metzger Joseph F. , Johnson Anna D. , Collins William S. , McGann Virginia
Published: December 2020

Release of
Staphylococcus aureus
enterotoxin B (SEB) into the culture medium was initiated during the mid-log phase of growth. A medium consisting of 4% N-Z Amine A (Sheffield), 0.2% dextrose, and 1% yeast extract supported maximum production of SEB. Although pH of the medium during cultivation did not significantly affect the growth curve of the organism, the time required for detectable excretion was affected, as was the final yield. Optimal conditions for SEB production were achieved with pH control at 7.0; alkaline control (pH 8.0) produced only minimal amounts of toxin, whereas acid control (pH 6.0) resulted in 50% reduction in yield. Slightly less SEB was produced when there was no extrinsic pH control, and cultures were buffered only by media constituents and by-products of growth. With pH control at 7.0, deletion of 0.2% dextrose from the medium resulted in 40% reduction in the 8-h yield. There was also a delay in production during early stages of fermentation.
Estimation of Growth Rate from the Mitotic Index
Authors: Chung King-Thom , Nilson Edgar H. , Case Marilyn J. , Marr Allen G. , Hungate Robert E.
Published: December 2020

The growth rate of a eukaryotic population dividing at a constant rate can be estimated from the equation,

t
m
/g

ln 2 = ln (1 + R), in which

t
m

is the time required for mitosis,
g
is the generation time, and
R
is the fraction of cells undergoing mitosis. Values for

t
m

and
R
can be determined by direct microscope examination of the population. The validity of the derived equation has been checked with an exponentially growing culture of a prokaryote,
Escherichia coli
, in which chloramphenicol was administered to inhibit protein synthesis. Cells having enough protein completed the division process whereas the rest of the population was inhibited. From the plot of the growth curve before and after administration of chloramphenicol,

t
m

and
R
were estimated. The calculated and actual growth rates were almost identical.
Amino Acid Requirements for the Production of Enterotoxin B by
Staphylococcus aureus
S-6 in a Chemically Defined Medium
Authors: Miller Richard D. , Fung Daniel Y. C.
Published: December 2020

A minimal chemically defined medium has been developed for growth (approximately 25 Klett units) and production of detectable enterotoxin B (approximately 5-6 μg/ml) by
Staphylococcus aureus
S-6. This medium contains monosodium glutamate as a source of carbon, nitrogen, and energy, three additional amino acids (arginine, cystine, and phenylalanine), six inorganic salts, and four vitamins. Increasing the concentrations of several amino acids in a series of defined media gave no increase in enterotoxin production. Apparently the limiting factor for growth and enterotoxin production in these media is the biosynthesis of one or more missing amino acids, rather than the concentration of the amino acids present in the media. An additional requirement for proline and valine was observed when glucose was added as the primary source of energy. When compared to complex media, our results indicated that the inhibitory effect of glucose on enterotoxin synthesis in defined media was less evident or totally absent.
Evaluation of Potential Risk of Botulism from Seafood Cocktails
Authors: Lerke Peter
Published: December 2020

Clostridium botulinum
E could not be detected in 35 samples of commercial seafood cocktails, ranging in pH from 4.10 to 4.85. At 30 C, toxinogenesis in homogenates acidified with a citric-acetic acid mixture was prevented at pH 4.86 or lower for crabmeat and at 5.03 or lower for shrimp. Measurements of the rate of acid penetration into the centers of large pieces of flesh indicated that the already small risk of botulism from seafood cocktails could be completely eliminated by using a cocktail sauce at a maximum pH of 3.70 and by cooling the final product to at least 10 C for 24 h.
Metabolism of Nitrilotriacetate by Cells of
Pseudomonas
Species
Authors: Tiedje J. M. , Mason B. B. , Warren C. B. , Malec E. J.
Published: December 2020

A
Pseudomonas
species was isolated from soil which could degrade nitrilotriacetate (NTA) to CO
2
, H
2
O, NH
3
, and cellular constituents without the accumulation of significant quantities of intermediates either in the presence or absence of several inhibitors. After extensive gas chromatography analysis, small quantities of aspartate, glycine, and aconitate were the only detectable compounds to accumulate during NTA degradation, and these compounds were not excreted from the cells. Manometric studies indicated that iminodiacetate, glycine, and glyoxylate are possible intermediates, whereas
N
-methyliminodiacetate, sarcosine, and acetate are not. The data are consistent with an oxidative cleavage of the C—N bond of NTA as the initial degradation step.
Identification of
Actinomyces, Arachnia, Bacterionema, Rothia
, and
Propionibacterium
Species by Defined Immunofluorescence
Authors: Holmberg Kenneth , Forsum Urban
Published: December 2020

Fractionated fluorescein-isothiocyanate (FITC)-conjugated immunoglobulin G (dye-to-protein ratio <10), produced against whole cells of
Actinomyces
spp.,
Arachnia, Bacterionena, Rothia
, and
Propionibacterium
spp., give species-specific conjugates with controlled nonspecific staining reactions when appropriately diluted on the basis of their antibody content (10 mg/ml). Using this standardization in immunofluorescence, serotype-specific conjugates are also available after dilution for all serotypes of these organisms except for
Actinomyces viscosus
type 2, and
Propionibacterium acnes
type 1. Adequately adsorbed conjugates could be used to differentiate these serotypes from
A. viscosus
type 1 and
P. acnes
type 2, respectively. A serological classification in defined immunofluorescence corresponded to species and serotype designation proposed on the basis of other serological analysis and biochemical characteristics. This includes a separation in immunofluorescence of two serotypes of
Propionibacterium acnes
. The detection of certain actinomycetes of the family
Actinomycetaceae
and
Propionibacterium
species by the defined immunofluorescence in direct smears prepared from clinical specimens agreed to 88% with parallel culturing when including a prereduced (PRAS) medium technique for isolation. Qualitative studies revealed that single cells of these organisms could be specifically identified by immunofluorescence when admixed with morphologically similar bacteria and a large number of other contaminants.
Interacting Effects of pH, Temperature, and Salt Concentration on Growth and Survival of
Vibrio parahaemolyticus
Authors: Beuchat L. R.
Published: December 2020

Thermal resistance and minimal pH and temperature conditions for growth of
Vibrio parahaemolyticus
in artificial media containing 3 and 7% sodium chloride were studied. Growth was observed at pH 4.8 and at 5 C.
Oxidation and Reduction of D-Xylose by Cell-Free Extract of
Pichia quercuum
Authors: Suzuki Toshiyuki , Onishi Hiroshi
Published: December 2020

The fermentation mechanism of the simultaneous production of D-xylonic acid and xylitol from D-xylose by
Pichia quercuum
was studied by using a cell-free enzyme preparation. Nicotinamide adenine dinucleotide phosphate (NADP)-dependent D-xylose dehydrogenase activity and NADP-dependent D-xylose reductase activity were detected, and the oxido-reduction reaction of D-xylose was able to couple through regeneration of NADP and NADPH to produce D-xylonic acid and xylitol.
Microbial Formation of Nitrosamines In Vitro
Authors: Ayanaba Abateni , Alexander Martin
Published: December 2020

Mortierella parvispora
and an unidentified bacterium converted trimethylamine to dimethylamine, and the bacterium (but not the fungus) formed dimethylnitrosamine in the presence of nitrite. Dimethylnitrosamine also appeared in cell suspensions of
Escherichia coli
and
Streptococcus epidermidis
and in hyphal mats of
Aspergillus oryzae
incubated with dimethylamine and nitrate. Suspensions of a number of microorganisms produced
N
-nitrosodiphenylamine from diphenylamine and nitrite at pH 7.5, and soluble enzymes catalyzing the
N
-nitrosation of diphenylamine were obtained from two of these organisms. In the presence of these enzymes, several dialkylamines were converted to the corresponding
N
-nitroso compounds.
Production of a Sporulation Pigment by
Streptomyces venezuelae
Authors: Scribner H. E. , Tang Terry , Bradley S. G.
Published: December 2020

Streptomyces venezuelae
S13 produced a pH-indicating sporulation pigment on a glucose-salts-agar medium consisting of glucose, KNO
3
, MgSO
4
, and Na
2
HPO
4
, pH 7. Pigmentation on this medium appeared to be closely associated with sporulation, which normally required 5 to 7 days at 30 C. The pigment was soluble in water as well as in a number of organic solvents. Butanol-extracted pigment exhibited absorption maxima at 430 and 520 nm at pH 3 and 12, respectively. Although many salts of organic acids and amino acids could replace glucose as the sole carbon source in basal salts-agar medium for growth and pigmentation, most sugars that were tested supported good growth but negligible pigmentation. Among the nitrogenous substances tested, KNO
3
was most desirable for pigmentation. The organism did not exhibit any specific requirements for divalent cations with respect to growth and pigmentation. In the absence of MgSO
4
, however, glucose-salts-agar prepared by autoclaving all components together failed to support growth. The production of the sporulation pigment on glucose-salts-agar was comparable to that obtained on tomato paste-oatmeal-agar medium. Incorporation of partially purified pigment material into broth medium that did not normally support sporulation induced sporulation, and amino acid-salts-agar medium could induce vegetative mycelia to pigment when transferred from medium that did not support either pigmentation or sporulation.
Intergenic Complementation of Glucoamylase and Citric Acid Production in Two Species of
Aspergillus
Authors: Chang L. T. , Terry Carol A.
Published: December 2020

All auxotrophs of
Aspergillus foetidus
and all but two auxotrophs of
A. niger
which we isolated yield glucoamylase and citric acid, respectively, at levels below that of the prototrophic strain from which they were derived. Results of representative heterokaryon tests suggest that the nucleus was principally responsible for the inheritance of citric acid or glucoamylase production. Most somatic diploid strains of
A. foetidus
gave rise to higher yields of glucoamylase when compared to their haploid component strains. Both heterokaryons and somatic diploid strains of
A. niger
synthesized between auxotrophs which were simultaneously reduced in citric acid yields also gave rise to enhanced yields when compared with their haploid components. The yields of a heterokaryon and somatic diploid synthesized between two high producers of citric acid were not higher than those of respective haploid components. We concluded from these results that gene dosage (or ploidy) does not increase the yield of citric acid. The apparent enhancement in yields observed in diploids or heterokaryons synthesized between auxotrophs with reduced yields in both species can be interpreted as resulting from intergenic complementation.
Potential Pathogens in the Environment:
Klebsiella pneumoniae
, a Taxonomic and Ecological Enigma
Authors: Brown Carol , Seidler Ramon J.
Published: December 2020

A nitrogen-deficient medium and m-Endo agar were employed in the isolation of members of the tribe
Klebsielleae
from surfaces of vegetables and seeds. With m-Endo agar at an incubation temperature of 37 C, nearly 50% of the vegetables and seven out of seven seed samples yielded organisms which biochemically and serologically were identified as
Klebsiella pneumoniae
, Viable counts were generally in the range of 10
3
cells per g of vegetable peel or seed. Organisms classified as
K. pneumoniae
exhibited seven different IMViC patterns, with the --++, ++++, and -+++ patterns most common. Seven of the eleven
K. pneumoniae
serotypes encountered have previously been isolated from human urinary tract and other infections. Fifty percent of the 40
K. pneumoniae
examined exhibited positive acetylene-reducing activity, i.e., they possessed the capability for fixing N
2
. Vegetables containing
K. pneumoniae
may constitute a potential reservoir for human nosocomial genitourinary or other infections.
Indirect Fluorescent-Antibody Method for the Identification of
Corynebacterium vaginale
Authors: Vice John L. , Smaron Mary F.
Published: December 2020

The indirect fluorescent-antibody technique was employed in an attempt to develop a rapid method of identification of
Corynebacterium vaginale
. Six reference strains and ten clinical isolates selected on the basis of morphology and conventional biochemical tests were compared. Antisera were prepared in rabbits against the six reference strains. The most satisfactory antiserum was that prepared using strain 14018 grown diphasically (14018 Di) as the antigen. Certain of the antisera did exhibit a cross-reacting titer when reacted against
Corynebacterium diptheriae, Corynebacterium xerosis
, or
Lactobacillus acidophilus
. However, antisera adsorbed with these bacteria did not exhibit a significant decrease in titer when reacted against the homologous strain. Various other species of
Corynebacterium
as well as species of
Nocardia, Actinomyces, Hemophilus
, and
Streptococcus
did not fluoresce with the antisera. A specific antiserum was prepared by adsorbing anti-14018 Di with
L. acidophilus
. The adsorption removed the cross-reacting antibody but did not affect the staining reaction with
C. vaginale
strains. All reference strains and clinical isolates characterized as
C. vaginale
gave a definite positive reaction with the adsorbed anti-14018 Di. The specificity of the reactions was assessed by adsorbing the antiserum with the homologous strain. The data suggest that the indirect staining method will be of value in the rapid presumptive identification of
C. vaginale
.
Culture of Ethiopian Strains of
Borrelia recurrentis
Authors: Dodge Ruth W.
Published: December 2020

A number of standard bacteriological media with supplements were tested for their ability to support in vitro growth of Ethiopian strains of
Borrelia recurrentis
. Propagation of 18 out of 21 strains occurred in Trypticase soy yeast broth to which bovine albumin (fraction V),
N
-acetyl glucosamine, and sodium pyruvate had been added. This medium supported a population of 10
7
organisms per ml and yielded a harvest of four to five times the original inoculum during the logarithmic phase of growth. Maximal yield varied from 1.4 × 10
7
to 3.4 × 10
7
organisms per ml. Generation time in optimal media was 11.3 h. Lesser multiplication of organisms occurred in other media tested. Strains from primary cultures were infective for the green monkey. Recovery of viable organisms from subculture has not been successful.
Effect of Temperature of Incubation on Performance of Media in the Detection of Enteric Pathogens
Authors: Taylor Welton I. , Schelhart Dorothy
Published: December 2020

The effect of incubation temperatures on the efficacies of both plating media and transport or enrichment broths was determined by the analysis of 391 diarrheal stools for salmonellae and shigellae. Each analysis resulted in 90 observations. Stool specimens were homogenized in saline and used to inoculate eosin methylene blue (EMB), Salmonella-Shigella (SS), and xylose lysine deoxycholate (XLD) agar plates, Amies and Cary-Blair (CB) transport media, and gram-negative (GN) enrichment broth. All media were incubated at 25, 30, and 35 C for 24 and 48 h. In order of efficacy, GN and saline were significantly better than Amies and CB, which were still better than direct streaking for both salmonellae and shigellae. Forty-eight hours was a significant improvement over 24 h only at 25 C on direct streaking for both pathogens. Salmonella detection was also improved at 30 over 25 C on direct streaking. In direct plating, XLD was better than both SS and EMB for both pathogens. After broths, for salmonellae, XLD > SS > EMB, and for shigellae, XLD > EMB > SS, with all differences significant. SS agar was significantly improved for detection of shigellae with 48-h broth inocula versus 24-h broth inocula. The differences thus observed at the various temperatures tested proved to be less important than the media used. The efficient media, GN broth, saline-stool, and XLD were shown to be affected very little by either temperature or time variance of the magnitude tested.
Enhancement of Co-Metabolism of Chlorobenzoates by the Co-Substrate Enrichment Technique
Authors: Horvath R. S.
Published: December 2020

Chlorinated benzoates were degraded by bacteria contained in an activated sludge inoculum by a co-metabolic mechanism. This decomposition began after an initial lag period of 4 days and accounted for 63 to 69% degradation in 28 days. The co-substrate enrichment technique, using glucose as co-substrate, increased both the rate of microbial decomposition of the benzoates and the total amount of substituted aromatic compounds degraded.
Negative Chemotaxis of Marine Bacteria to Toxic Chemicals
Authors: Young L. Y. , Mitchell Ralph
Published: December 2020

The positive chemotactic responses of motile marine bacteria were reversed by the addition of sublethal concentrations of a toxic chemical. The negative chemotactic effect was observed with a wide range of toxicants including heavy metals and hydrocarbons. This phenomenon may be utilized to develop new approaches for control of marine fouling.
Identification of the
Prototheca
Species by Immunofluorescence
Authors: Sudman M. Sam , Kaplan William
Published: December 2020

Studies were carried out to develop fluorescent antibody reagents for the identification of the
Prototheca
species and for their differentiation from morphologically similar fungi of various genera in formalin-fixed tissues. Antisera against representative isolates of
P. filamenta, P. moriformis, P. stagnora, P. wickerhamii
, and
P. zopfii
were produced in rabbits. Antiglobulins, labeled with fluorescein-isothiocyanate that intensely stained most cells of the homologous species, were selected for use as potential diagnostic reagents. By adsorbing the conjugates with selected heterologous cross-staining protothecae, reagents that were both sensitive and specific were obtained. Evaluation of the adsorbed conjugates with sections of tissue infected with protothecae, sections of tissue infected with morphologically similar fungi, and cultures of protothecae showed that these reagents are useful for the rapid and reliable identification of the
Prototheca
species.
Avian
Salmonella
-Stained Microtest Antigens Produced on Solid Media
Authors: Williams J. E. , Whittemore A. D.
Published: December 2020

Procedures are described for the preparation of
Salmonella pullorum
and
Salmonella typhimurium
tetrazolium-stained microagglutination and microantiglobulin antigens with solid media for culture propagation. Cell suspensions were found to be more easily harvested from solid medium than from previously used liquid medium, and greater yields of antigen were obtained. Liquid medium microagglutination and microantiglobulin test antigens were found to be more sensitive than those prepared on solid medium. The microtest antigens produced on solid medium were easier to prepare and in serological tests gave titers more comparable to those demonstrated with the standard macroscopic tube agglutination test.
New Formaldehyde Base Disinfectants
Authors: Trujillo Ralph , Lindell Kermit F.
Published: December 2020

Preparations of formaldehyde in various organic liquids—ethylene glycol, glycerol, and propylene glycol—serve as effective disinfectants towards microbial vegetative cells and spores. This disinfection is a temperature-dependent process and is manifest when these formaldehyde base disinfectants are dissolved in water. The irritating vapors associated with formaldehyde disinfection are not present in either of these new formaldehyde base disinfectants or in aqueous solutions of them.
Survival of
Vibrio parahaemolyticus
in Oyster Shellstock at Two Different Storage Temperatures
Authors: Johnson W. G. , Salinger A. C. , King W. C.
Published: December 2020

In oyster shellstock harvested from Maryland waters
Vibrio parahaemolyticus
was found to be present, to survive storage for at least 3 weeks at 4 C, and to multiply after being held for 2 to 3 days at 35 C.
Patulin Production in Apples Decayed by
Penicillium expansum
Authors: Wilson D. M. , Nuovo G. J.
Published: December 2020

Sixty isolates of
Penicillium expansum
were tested for patulin production in decaying apples. All the isolates were found to produce the mycotoxin patulin as determined by thin-layer chromatography. Since patulin is known to be stable in many apple products, the results indicate that apple products made partially from apples decayed by
P. expansum
will contain patulin which may present a health hazard. The results also suggest that patulin may be important in the decay of apples by
P. expansum
.
Gamma Radiation Inactivation of Coxsackievirus B-2
Authors: Sullivan Robert , Scarpino Pasquale V. , Fassolitis Alexander C. , Larkin Edward P. , Peeler James T.
Published: December 2020

The radioresistance of coxsackievirus B-2 was studied when the virus was suspended in Eagle minimal essential medium, distilled water, cooked ground beef, and raw ground beef and irradiated at various temperatures in a cobalt-60 gamma radiation source. The number of surviving viruses at given doses of radiation was determined by a plaque assay system. All destruction curves indicated a first-order reaction. When the virus was irradiated in minimal essential medium at temperatures of -30, -60, and -90 C,
D
values (in Mrad) were 0.69, 0.59, and 0.64, respectively. When the virus was suspended in water and irradiated at -90 C, the D value was 0.53. Cooked ground beef containing the virus was irradiated at temperatures ranging from 16 to -90 C. The D values were 0.70 (16 C), 0.76 (0.5 C), 0.68 (-30 C), 0.78 (-60 C), and 0.81 (-90 C). Raw ground beef containing the virus was irradiated at -30, -60, and -90 C, and the D values were respectively 0.75, 0.71, and 0.68. The D values indicate that the rate of viral inactivation was dependent on the suspending menstrum.
Production of Ochratoxins A and B on Country Cured Ham
Authors: Escher F. E. , Koehler P. E. , Ayres J. C.
Published: December 2020

Two strains of
Aspergillus ochraceus
and six of
Penicillium viridicatum
isolated from country cured hams were screened for production of ochratoxins A and B. None of the isolated
P. viridicatum
strains yielded detectable amounts of ochratoxin A or B, whereas both strains of
A. ochraceus
produced ochratoxins A and B on rice, defatted peanut meal, and country cured ham. After 21 days of incubation on ham, one-third of the toxin was found in the mycelial mat on the ham surface, whereas two-thirds had penetrated into the meat to a distance of 0.5 cm.
Needless Retesting of Quality-Assured, Commercially Prepared Culture Media
Authors: Nagel Janice G. , Kunz Lawrence J.
Published: December 2020

Current revival of interest in quality control of bacteriological culture media prompted this laboratory to develop and implement a system of quality control testing of media purchased from commercial manufacturers. During 8 months we tested more than 900 lots of 46 different media representing 350,000 units of culture media purchased from two major and one minor supplier(s). Only 17 lots were found to be unsatisfactory. This experience raised a question about the real necessity for extensive retesting by users of commercially prepared, quality-assured media. It is suggested that primary responsibility for quality control be placed on the relatively few manufacturer-vendors rather than on the multiple purchaser-users, who may not possess either the expertise or the resources for quality control programs.
Rapid Detection of Gram-Negative Bacteriuria by Use of the
Limulus
Endotoxin Assay
Authors: Jorgensen J. H. , Carvajal H. F. , Chipps B. E. , Smith R. F.
Published: December 2020

The
Limulus
in vitro endotoxin assay was evaluated as a possible method for the prompt detection of significant gram-negative bacteriuria in children. This assay is capable of detecting endotoxin associated with intact cell walls of viable gram-negative bacteria as well as free endotoxin. Quantitative results are obtained following a 1-h incubation of
Limulus
lysate and 10-fold dilutions of otherwise untreated urine. A standard curve of
Limulus
activity and viable cell counts of
Escherichia coli
and
Klebsiella pneumoniae
in urine demonstrated that a positive
Limulus
reaction at a dilution of 1:100 or 1:1,000 indicated a colony count of at least 100,000 bacteria/ml. A positive
Limulus
reaction only from undiluted urine or at a dilution of 1:10 indicated less than 100,000 cells/ml. These experimental observations were confirmed by comparing the
Limulus
test with quantitative plate counts on 209 urine specimens from a mixed pediatric population. These results indicate that the
Limulus
assay is a simple, accurate method for rapid presumptive detection of gram-negative bacteriuria in patients where an immediate diagnosis is needed. This test would also seem promising for screening large patient populations for bacteriuria or for monitoring the effectiveness of treatment of urinary tract infections.
Preparation, Sensitivity, and Specificity of
Limulus
Lysate for Endotoxin Assay
Authors: Jorgensen James H. , Smith Rodney F.
Published: December 2020

Limulus
amoebocyte lysate was prepared from a total of 180 crabs during 1971 and 1972 by using a slightly modified lysate preparation procedure. Marked variability of lysate potency was noted both years. In addition, lysate quality appeared diminished in 1972 as compared with 1971. Different lysate batches were evaluated for potency by using a variety of endotoxin preparations. Variations in batch potencies were observed, but little variation in reactivity among different endotoxin preparations was noted. Use of potent lysate batches allowed detection of endotoxin concentrations as low as 100 pg/ml. No endotoxinlike activity was observed from 11 different strains of yeast by use of the
Limulus
assay.
Stimulation of Lactic Acid Bacteria by a
Micrococcus
Isolate: Evidence for Multiple Effects
Authors: Nath K. R. , Wagner B. J.
Published: December 2020

Growth of, and rate of acid production by, six cultures of lactic acid bacteria were increased in the presence of
Micrococcus
isolate F4 or a preparation of its capsular material. Concentrations of hydrogen peroxide found in pure cultures of the lactic acid bacteria were not detectable, or were greatly reduced, in mixed culture with
Micrococcus
isolate F4. The capsular material was not as effective as whole cells in preventing accumulation of H
2
O
2
. Catalase stimulated growth of, and the rate of acid production by, the lactic acid bacteria, but not to the same extent as
Micrococcus
isolate F4 in some cultures. The existence of two mechanisms for micrococcal stimulation of the lactic acid bacteria is postulated. One mechanism involves removal of H
2
O
2
; the other has not been characterized.
Evaluation of Streptozyme and Antistreptolysin O Tests in Streptococcal Pyodermal Nephritis
Authors: Bergner-Rabinowitz Sonya , Ofek I. , Fleiderman S. , Zohar M. , Rabinowitz K. , Ginsburg I.
Published: December 2020

The evaluation of the streptozyme test in sera from 34 patients with streptococcal pyodermal nephritis was studied. Ninety-seven percent of the patients developed high titers of antistreptozyme antibodies on the first bleeding after hospitalization, in contrast to only 40% of patients who developed elevated antistreptolysin O titers. The high antistreptozyme titers declined during convalescence and reached normal levels in the sixth month after onset of the disease. The most significant fall in titers occurred between 1 and 2 months from the onset of disease. The streptozyme test may be particularly helpful as a rapid screening test for antibodies in streptococcal pyodermal nephritis.
Improved Hemagglutination Inhibition Assay for Mammary Tumor Virus Antigen
Authors: Gillette Ronald W. , Junker Diane
Published: December 2020

It is our experience that the use of sheep red blood cells pretreated with formaldehyde and pyruvaldehyde before sensitizing with viral antigen yields results that are comparable to that obtained by using the tannic acid method. The double aldehyde method provides the added advantage of being useful for assaying the viral antigen content in substances which contain high levels of interfering substances which would preclude the use of other assay methods.
Tryptophol Formation by
Zygosaccharomyces priorianus
Authors: Rosazza J. P. , Juhl R. , Davis P.
Published: December 2020

Zygosaccharomyces priorianus
converted L-tryptophan to tryptophol and to small quantities of indole-3-acetic acid. Neither tryptophol nor indole-3-acetic acid was metabolized when added separately to growing cultures. The possible intermediacy of indole-3-pyruvic acid, indole-3-acetaldehyde, and tryptamine in the degradation of L-tryptophan was tested by feeding these compounds to
Z. priorianus
and
Saccharomyces cerevisiae
. Indole-3-pyruvic acid and indole-3-acetaldehyde were converted to tryptophol and indole-3-acetic acid, with the latter accumulating only in small amounts. Tryptamine was converted to its
N
-acetyl derivative by these organisms. A qualitative study was made on the metabolism of L-phenylalanine, L-tyrosine, and L-5-hydroxytryptophan by these organisms. Like L-tryptophan, these amino acids were metabolized to their respective alcohol and acid derivatives. Of a large number of organisms tested, the yeasts possessed the highest capacity for degrading L-tryptophan to tryptophol.
Conditions That Affect the Colorimetric Analysis of Lipopolysaccharide from
Escherichia coli
and
Treponema pallidum
Authors: Zey Pinina , Jackson Sally
Published: December 2020

Material extracted from the Nichols nonpathogenic strain of
Treponema pallidum
by phenol-water was analyzed by employing a recently reported colorimetric test for detection of lipopolysaccharide (LPS). The fraction isolated from
T. pallidum
, in combination with the reagent dye, absorbed maximally at a wavelength in the range reported to be positive for LPS. Comparison of this reaction to that of a commercial preparation of
Escherichia coli
LPS revealed that time and temperature of incubation of the LPS-dye complexes were important variables which had marked but different effects on the LPS of the two sources. However, with careful control of these parameters, concentration-dependent standard curves were established for LPS of both sources. Our results indicate the cell wall of
T. pallidum
is similar to that of gram-negative organisms.
Mass Airflow Cabinet for Control of Airborne Infection of Laboratory Rodents
Authors: McGarrity Gerard J. , Coriell Lewis L.
Published: December 2020

A mass airflow cabinet for handling and housing of laboratory rodents has been developed and tested. The unit consists of a high-efficiency particulate air filter and uniform distribution of air at a vertical velocity of 19 cm per s. Animals are maintained without bedding in mesh-bottomed cages that rest on rollers for rotation inside the cabinet. There is an air barrier of 90 cm per s separating the cabinet air from room air. Sampling for airborne bacteria yielded an average of 0.03 colony-forming units (CFU) per ft
3
of air inside the cabinet, whereas 28.8 CFU per ft
3
was simultaneously detected outside the cabinet during housekeeping, a reduction of almost three logs. The efficiency of the air barrier was tested by aerosolization of T3 phage. When phage was aerosolized 5 cm outside the cabinet, no phage could be detected 5 cm inside when the fans were operating; with the fans off an average of 1.6 � 10
4
plaque-forming units (PFU) per ft
3
was detected in six tests. Aerosolization of phage inside the cabinet yielded an average of 9 � 10 PFU per ft
3
outside; an average of 4.1 � 10
6
PFU per ft
3
were detected with the fans not in operation, a reduction of more than four logs. In-use studies on effectiveness showed that the cabinet significantly reduced the incidence of mice originally titer-free to Reo-3 virus. Hemagglutination inhibition antibodies to Reo-3 were detected in 9/22 (42%) mice housed in a conventionally ventilated animal laboratory while no seroconversion was detected in any of 22 mice housed in the mass air flow cabinet in the same laboratory.
Methoxyhydroquinone, an Intermediate of Vanillate Catabolism by
Polyporus dichrous
Authors: Kirk T. Kent , Lorenz L. F.
Published: December 2020

Vanillate was metabolized by
Polyporus dichrous
in liquid culture via methoxyhydroquinone. Protocatechuate, gentisate, and hydroquinone were not affected by vanillate-metabolizing mycelial pellets that readily degraded methoxyhydroquinone.
Production and Purification of the Metalloprotease of
Bacillus polymyxa
Authors: Fogarty William M. , Griffin Patrick J.
Published: December 2020

The nutritional and environmental factors relating to the production of an extracellular protease by
Bacillus polymyxa
were investigated. The enzyme was produced in all media that supported growth of the microorganism, irrespective of the carbon source used. Arabinose and hydrolyzed starch, however, gave highest yields. The nature of the peptone had a significant effect on the level of protease produced. Calcium and manganous ions exerted a beneficial effect on protease production. Highest enzyme levels were obtained when the initial pH of the medium was within the range 5.9 to 7.0. When the pH of the medium was not controlled during the fermentation, the accumulation of the enzyme paralleled the growth of the microorganism and reached a maximum towards the end of the exponential phase. With a fixed pH of 6.8, the level of protease was only one-fifteenth of that obtained when the culture was allowed to maintain its own pH. In addition, accumulation of the protease reached a maximum somewhat earlier, i.e., in the mid-log phase of growth. A 70-fold increase in the specific activity of the protease was obtained by ammonium sulfate and acetone fractionation followed by gel filtration on Sephadex G-100. The purified protease behaved as a homogenous entity when eluted by a sodium chloride gradient from CM-cellulose at pH 6.9. An overall enzyme recovery of 60% was obtained.
Rapid Identification of the Taxon
Rhodochrous
in the Clinical Laboratory
Authors: Stottmeier K. D. , Molloy Mary E.
Published: December 2020

Degradation of ethylene glycol in Middlebrook 7H-10 agar medium by 26 out of 29 strains of the taxon
rhodochrous
seems to permit its separation from rapidly growing mycobacteria and certain actinomycetes which only exceptionally showed this property.
Pseudomonas oleovorans
Hydroxylation-Epoxidation System: Additional Strain Improvements
Authors: Schwartz Robert D. , McCoy C. J.
Published: December 2020

The isolation and characterization of a strain of
Pseudomonas oleovorans
which epoxidates 1-octene at a rate nine times that of the original strain are described. In addition, it has been confirmed that a greater amount of the mono-epoxide product is formed from 1,7-octadiene than is formed from 1-octene. 1,7-octadiene will not support growth, but will induce the enzymes required for epoxidation.
Biological Containment Facility for Studying Infectious Disease
Authors: Kuehne Ralph W.
Published: December 2020

To effectively characterize newly recognized viruses (Marburg, Lassa, etc.) and to study other highly virulent infections for which no effective prophylaxis or therapy exists, special containment facilities must be utilized and conventional techniques modified to minimize risk to laboratory personnel. This paper describes a laboratory suite for such studies, contained within a larger research facility; two separate biological safety cabinet systems, animal rooms support laboratories, change room facilities, shower, air lock, and other safety features are contained in the area. Details of design, construction, airflows, and equipment are described in addition to a discussion of operation, techniques, and modification of laboratory equipment utilized in actual studies.
System for Studying Uninfected and Virus-Infected Cell Cultures in Hyperbaric Chambers
Authors: Leong J. K. L. , Schultz W. W. , Zebovitz E. , Schlamm N. A.
Published: December 2020

Equipment and techniques previously used to investigate the effect of hyperbaric gases on bacteria were modified to permit comparable investigations with uninfected and virus-infected tissue cell cultures. This report describes the modified equipment and related methodology. Use of the system is illustrated with findings on the effect of oxygen-helium mixtures at 68 atm on cell physiology and virus growth in two cell types. Our results suggested that, under those experimental conditions, several synthetic processes in chick fibroblast monolayers are inhibited but that Sindbis virus growth in the cells is increased. Growth of Japanese encephalitis virus in porcine kidney cells was found to be unaffected by oxygen-helium gas at partial pressures of oxygen between 0 and 700 mm Hg, but morphological alterations in the cells occurred at low and high pO
2
levels.
Direct Fluorescent-Antibody Technique for the Microbiological Examination of Food and Environmental Swab Samples for Salmonellae
Authors: Insalata N. F. , Mahnke C. W. , Dunlap W. G.
Published: December 2020

Comparative studies of a modified fluorescent-antibody procedure and the 5 to 7 day method used by the Association of Official Analytical Chemists for the detection of
Salmonella
were made on 151 samples of wheat products and 183 swab samples. The agreement between the two methods for the 334 samples tested was 92.5%. Food samples yielded 94.7% agreement, whereas the swab samples yielded 90.7% agreement. There were 7.5% false positives for the total number of samples tested. No false negatives were obtained by using the fluorescent-antibody method.
Comparison of Brilliant Green Agar and Hektoen Enteric Agar Media in the Isolation of Salmonellae from Food Products
Authors: Goo Velma Y. L. , Ching George Q. L. , Gooch John M.
Published: December 2020

Brilliant Green (BG) agar and Hektoen enteric (HE) agar media were compared for their efficiency in isolating salmonellae from various food products. Of the 11,226 food specimens examined, 1,662 (or 14.9%) yielded salmonellae. Of this number, 1,475 (88.7%) were recovered from BG agar and 1,315 (79.1%) were recovered from HE agar media. The results indicate that BG agar is more effective in isolating salmonellae from food products. A smaller subsidiary study showed HE agar to be more selective than BG agar. Four hundred ten specimens yielded 92 nonlactose-fermenting isolants other than salmonellae on BG agar and only 11 such isolants on HE agar.
Tetrazolium Reduction as a Measure of Metabolic Activity for Glass-Adherent
Mycoplasma pneumoniae
Authors: DiVecchia Loretta , Somerson Norman L.
Published: December 2020

The reduction of tetrazolium was used to assay the metabolic capability of developing
Mycoplasma pneumoniae
cultures on glass. Generally, the amount of tetrazolium reduced correlates with the amount of growth as measured by protein. Until a culture enters the late phase of the growth cycle, the drop in pH of culture medium provides similar information. In this last stage of growth, protein appears to be leveling. The pH continues to fall, but tetrazolium reducing activity decreases. Thus, considering the entire
M. pneumoniae
growth cycle, formazan production is a more reliable measure of metabolic capability of the organisms than either protein or pH. The reduction of tetrazolium provides a quantitative means of assessing enzymatic activities of glass-adherent
M. pneumoniae
.