bluuebunny/crossref_metadata_2025 huggingface dataset:
Antiviral Activity in Tissue Culture Systems of bis-Benzimidazoles, Potent Inhibitors of Rhinoviruses
Authors: Schleicher J. B. , Aquino F. , Rueter A. , Roderick W. R. , Appell R. N.
Published: December 2020

(
S,S
)-1,2-bis(5-methoxy-2-benzimidazolyl)-1,2-ethanediol showed antiviral activity in monolayer tissue culture systems against 55 strains of rhinovirus, three types of poliovirus, and strains of type A and B coxsackieviruses. Neither the compound nor any of the analogues tested showed virucidal activity. Its antiviral activity was not associated with interference with viral attachment to or penetration into the cell. At a concentration of 0.1 mg/ml, this group of compounds was generally nontoxic to WI-38, primary bovine kidney, and African green monkey kidney cells and had antiviral activity with 100% inhibition of virus-induced cytopathic effects (CPE). At antiviral levels, these compounds prevented CPE of up to 10
6
median tissue culture infective dose units of virus and completely inhibited formation of new infective virions. The compounds showed antiviral activity both prophylactically and therapeutically against rhinoviruses. Infected cultures could be cleared of CPE up to 90 hr after infection.
Rapid Preparation of Hemagglutinins of Togaviruses from Infected Cell Culture Fluids
Authors: Della-Porta A. J. , Westaway E. G.
Published: December 2020

Antigens in infected cell culture fluids can be easily concentrated by polyethylene glycol precipitation to yield suitable hemagglutinating and complement-fixing antigens for several togaviruses.
Use of Pyocin 78-C2 in the Treatment of
Pseudomonas aeruginosa
Infection in Mice
Authors: Merrikin D. J. , Terry C. S.
Published: December 2020

Purified pyocin, administered parenterally to mice infected with sensitive strains of
Pseudomonas aeruginosa
, afforded significant protection against two of the three strains studied.
Inactivation of
Vibrio parahaemolyticus
in Distilled Water
Authors: Lee J. S.
Published: December 2020

Vibrio parahaemolyticus
cells are readily inactivated in distilled water. The time of exposure required to inactivate 90% of the cells was between 0.9 and 4.4 min.
Immunofluorescence Staining of Group B Coxsackieviruses
Authors: French Morris L. V. , Schmidt Nathalie J. , Emmons Richard W. , Lennette Edwin H.
Published: December 2020

Studies were conducted on the sensitivity and specificity of indirect fluorescent-antibody (FA) staining for identification of group B coxsackieviruses. Antisera produced in four different species (monkeys, rabbits, horses, hamsters) and immune ascitic fluids prepared in mice were compared for suitability in FA staining. The horse antisera showed high titers of nonspecific staining, and the rabbit antisera showed relatively low homologous FA titers. Immune reagents from monkeys, hamsters, and mice were used for homologous and heterologous testing against cell cultures infected with the various group B coxsackieviruses. Antisera or immune ascitic fluids produced in these three species showed some heterotypic and nonspecific staining at low dilutions, with the monkey antisera showing the highest heterotypic titers. However, the immune reagents could be diluted to a point where they gave no heterotypic reactivity, but still showed characteristic homotypic staining. Heterotypic staining appeared as diffuse, low-level staining of the cells, whereas homotypic staining revealed characteristic, brightly staining aggregates of viral antigen in the cytoplasm of the infected cells. By using hamster immune sera, appropriately diluted to eliminate heterotypic staining and yet give strong homotypic staining, it was possible to identify correctly 79 (93%) of 85 field strains of group B coxsackieviruses at the first passage level in BS-C-1 cells; the remainder of the strains were identified after two passages in BS-CS-1 cells. No incorrect identifications were made. A limited number of field strains of group B coxsackieviruses were passed into rhesus monkey kidney and human fetal diploid kidney cells, and these were all correctly identified by FA staining, even the strains which failed to produce a cytopathic effect in the human fetal diploid kidney cells. Two human heart and brain tissues from which coxsackievirus type B4 had been isolated failed to show homotypic FA staining in excess of nonspecific or heterotypic staining.
Microbial Degradation of Sterols
Authors: Marsheck William J. , Kraychy Stephen , Muir Robert D.
Published: December 2020

A process is described for the microbial degradation of cholesterol and plant sterols, to produce androsta-1, 4-diene-3, 17-dione and androst-4-ene-3, 17-dione, by two newly isolated bacteria designated
Mycobacterium
sp. NRRL B-3683 and
Mycobacterium
sp. NRRL B-3805. These myocbacteria produce substantial amounts of 17-ketonic compounds without appreciable degradation of the steroid nucleus. No ring degradation inhibitory agents are necessary. The first microbiological production of 20α-hydroxymethylpregna-1, 4-dien-3-one is also reported.
Growth of
Salmonella typhimurium
in Skim Milk Concentrates
Authors: Dega C. A. , Goepfert J. M. , Amundson C. H.
Published: December 2020

The influence of various levels of skim milk solids and temperature on the duration of lag phase, growth rate, and extent of growth of
Salmonella typhimurium
was investigated. The effect on growth of salmonellae (and a strain of
Escherichia coli
) of reduced pressure at a constant solids level and under conditions simulating vacuum condensation of skim milk was also studied.
S. typhimurium
grew when inoculated into skim milk solutions ranging from 10 to 60% solids and over a temperature range of 23 to 44 C. At 10 to 12 C, growth was evident only in the 10% skim milk. As the total solids level was increased or incubation temperature was deviated from the optimum, or both, there was an increase in the lag phase and generation time of salmonellae. A lower cell population also resulted. The generation time at 37 C of
S. typhimurium
incubated at atmospheric pressure was approximately one-half that in skim milk concentrates held under reduced pressure. In addition, a slightly longer lag phase and lower cell yield characterized the growth under reduced pressure. Concentration of skim milk had little or no effect on viability of salmonellae or
E. coli
when the vapor temperature in the vacuum pan was below the maximum growth temperature for salmonellae. Increasing the vapor temperature to 48 C caused a two-log reduction in viable organisms during the concentrating period (65 min).
Bacteria of Porcine Skin, Xenografts, and Treatment with Neomycin Sulfate
Authors: Smith Rodney F. , Evans Barbara L.
Published: December 2020

Homogenized 4-mm punch biopsies were taken from pigs and bacteriologically evaluated to determine the efficacy of surgical scrub procedures and the subsequent treatment of tissue with 0.5% neomycin sulfate-sodium bisulfite (neomycin-bisulfite) as a decontaminating agent. The majority of the lots of porcine skin taken directly from animals for xenografts in the treatment of burns contained viable bacteria at the time of grafting although scrubbing procedures substantially reduced the skin bacteria. The porcine bacteria consisted primarily of coagulase-negative staphylococci with most strains exhibiting caseinolytic and elastase activity. Staphylococci were the only abundant bacteria found in postscrub biopsies and in saline solutions used to wash the dermatome during its use. After an overnight exposure of grafting tissue soaked in neomycin-bisulfite, the spent neomycin-bisulfite solutions were tested for bacteriostatic and bactericidal activity by comparison to unused neomycin. All solutions tested were equal in bacteriostatic strength, but the bactericidal action of some spent solutions was decreased. Neomycin alone exerted a more lethal effect on sensitive bacteria than the neomycin-bisulfite solution. The desirability of having viable porcine skin for a xenograft necessitated using or discarding the tissue after storage in neomycin-bisulfite at 4 C for a maximum of 72 hr. Certain contaminating microorganisms were unaffected by antibiotic treatment, and the prolonged use of neomycin without bisulfite would have primarily eradicated only the porcine coagulase-negative staphylococci. Neither the presence of this group in grafting tissue nor their proteolytic activity had any observed adverse effect on xenografting success.
Relationship of Pathogenicity to Tobacco Leaves and Toxicity to Chicks of Isolates of
Alternaria longipes
Authors: Sobers E. K. , Doupnik Ben
Published: December 2020

One hundred thirty-seven single-conidium isolates of
Alternaria longipes
were tested for pathogenicity to tobacco leaves and for toxicity to 1-day-old chicks. Of 58 isolates pathogenic to tobacco, 43 (74.3%) had a significant effect on test chicks. Of 79 nonpathogenic isolates, 59 (74.7%) were nontoxic, 7 were toxic, and 13 were lethal. A relationship between pathogenicity and toxicity is suggested.
Analysis of Free Amino Acid Pools in Fungal Mycelia
Authors: Heathcote J. G. , Davies D. M. , Haworth C.
Published: December 2020

Free amino acid pools derived from three different types of fungal mycelia have been analyzed by the method of Heathcote and Haworth by using thinlayer chromatography. The preliminary extraction was carried out with boiling water and interfering proteins; peptides and salts were first removed by means of an ion-retardation resin. As far as determined, the results obtained represent the first quantitative analysis of fungal amino acid pools.
Degradation of Alkyl Benzene Sulfonate by
Pseudomonas
Species
Authors: Horvath R. S. , Koft B. W.
Published: December 2020

Pseudomonas
sp. HK-1 showed a direct relation between the concentration of alkyl benzene sulfonate (ABS) supplied and cell yields. Since growth on ABS alone did not occur, it was necessary to correlate the total energy obtained by the cells to the ABS concentration when glucose was supplied in a limiting concentration. Several types of metabolic attack in addition to the sulfonate removal were noted: (i) side-chain utilization as indicated by the production of tertiarybutyl alcohol and isopropanol and (ii) ring metabolism as indicated by the presence of phenol, catechol, mandelic acid, benzyl alcohol, and benzoic acid in spent growth media. Utilization of ABS was greatly enhanced by the presence of phenol. This enhancement suggests co-metabolism and that limited concentrations of phenolic products derived from ABS must be accumulated to get active metabolism of the ABS molecule.
Method for Accelerated Identification of Arboviruses After Inoculation of Mice
Authors: David-West Tam. S.
Published: December 2020

Sequential titration of infective virus and complement-fixing antigen in brain and liver of suckling mice infected with the following virus strains—Dugbe (a new arbovirus), Congo (related to Crimean hemorrhagic fever virus), yellow fever, dengue 1 and dengue 2—showed a progressive increase in titer after infection. High titers of both infective virus and complement-fixing antigen were demonstrated long before the mice showed clinical signs of infection. It is suggested that earlier isolation and identification of arboviruses from clinical and field specimens can be made if serological tests are done before mice are moribund.
Effect of Flaming Cotton-Plugged Tubes Upon the Contamination of Media During Culture Transfers
Authors: Brunker Tillmann , Fernāndez Bernal
Published: December 2020

The effect of flaming the mouth of cotton-plugged broth tubes upon the contamination of media during culture transfers was studied. It was shown that flaming did not reduce contamination significantly either under usual laboratory conditions or when the laboratory atmosphere had been seeded with a test organism so as to achieve higher rates of colony-forming settling particles.
Efficiency of Commercial Air Filters Against Marek's Disease Virus
Authors: Burmester B. R. , Witter R. L.
Published: December 2020

In a series of 10 replicate trials with susceptible chickens as indicators of the presence of virus in the air, filter B
1
(Dri Pak, American Air Filter Co.), which has a dust spot rating of 93 to 97%, and filter C (Astrocel), with a dioctyl phathalate aerosol rating of over 99%, completely removed Marek's disease virus (MDV) from highly contaminated air. However, air passed through filter B
2
(Duracel), with a dust spot rating of 34 to 45%, remained infectious. Thus, an air filter with a dust spot rating of over 93% will effectively remove MDV from the air. The smallest infectious particles in the air are estimated to be greater than 0.3 μm in diameter.
Mycoplasma: Growth Precipitation as a Serodiagnostic Method
Authors: Krogsgaard-Jensen A.
Published: December 2020

A serological test is described which is designated the growth precipitation test and is based on the release of diffusible compounds from mycoplasma strains. During growth of mycoplasmas on solid substrates, precipitation lines are formed with antibodies from homologous antisera independent of heat-labile serum factors. The application of the test as a serodiagnostic tool was investigated by performing a complete serological cross-test with 10 mycoplasma strains. The test was compared with the growth inhibition test, the complement fixation test, and the indirect hemagglutination test. It is demonstrated that the growth precipitation test has a good degree of specificity. The species and subspecies used here showed cross-reactions between serologically closely related strains, but these heterologous reactions occurred only after longer incubation than the homologous reactions.
Technique for Measuring
14
CO
2
Uptake by Soil Microorganisms In Situ
Authors: Smith David W. , Fliermans Carl B. , Brock Thomas D.
Published: December 2020

Uptake of
14
CO
2
in soils due to algae or sulfur-oxidizing bacteria was examined by incubation of soil samples with gaseous
14
CO
2
and subsequent chemical oxidation of biologically fixed radioactive isotope to
14
CO
2
for detection with a liquid scintillation counting system. The
14
CO
2
was added to the soil in the gas phase so that no alteration of the moisture or ionic strength of the soil occurred. Wet oxidation of radioactive organic matter was carried out in sealed ampoules, and the
14
CO
2
produced was transferred to a phenethylamine-liquid scintillation counting system with a simply constructed apparatus. The technique is inexpensive and efficient and does not require elaborate traps since several possible interfering factors were found to have no harmful effects. Experiments in coal mine regions and in geothermal habitats have demonstrated the ecological applicability of this technique for measurement of CO
2
fixation by sulfur-oxidizing bacteria and soil algae.
Cytopathogenic Test for Feline Leukemia Virus Infections
Authors: Rangan S. R. S. , Wong Mae Cheong , Moyer Patricia P. , Jensen E. M.
Published: December 2020

A mixed culture cytopathogenic effect with the development of multinucleated giant cells in feline leukemia virus-infected cultures after cocultivation with XC cells is described. This cytopathogenic effect has been utilized as a convenient visual marker for the detection and assay of feline leukemia virus in feline and canine embryo fibroblasts as well as in a canine tumor cell line, M-132-1. Comparison of the cytopathogenic reaction in the three cell lines indicates that the reaction is more rapid and pronounced in M-132-1 cells than in the embryo fibroblast cultures.
Differentiation of Sterol-Requiring from Sterol-Nonrequiring Mycoplasmas by Amphotericin B
Authors: Rottem S.
Published: December 2020

Growth inhibition of mycoplasmas by amphotericin B in a liquid medium was found to be a simple means of differentiating sterol-requiring from sterol-nonrequiring species.
Salmonella
Testing of Pooled Pre-Enrichment Broth Cultures for Screening Multiple Food Samples
Authors: Price W. R. , Olsen R. A. , Hunter J. E.
Published: December 2020

A method has been described for testing multiple food samples for
Salmonella
without loss in sensitivity. The method pools multiple pre-enrichment broth cultures into single enrichment broths. The subsequent stages of the
Salmonella
analysis are not altered. The method was found applicable to several dry food materials including nonfat dry milk, dried egg albumin, cocoa, cottonseed flour, wheat flour, and shredded coconut. As many as 25 pre-enrichment broth cultures were pooled without apparent loss in the sensitivity of
Salmonella
detection as compared to individual sample analysis. The procedure offers a simple, yet effective, way to increase sample capacity in the
Salmonella
testing of foods, particularly where a large proportion of samples ordinarily is negative. It also permits small portions of pre-enrichment broth cultures to be retained for subsequent individual analysis if positive tests are found.
Salmonella
testing of pooled pre-enrichment broths provides increased consumer protection for a given amount of analytical effort as compared to individual sample analysis.
Mechanism of Proline Production by
Kurthia catenaforma
Authors: Kato Jyoji , Fukushima Hiroshi , Kisumi Masahiko , Chibata Ichiro
Published: December 2020

The fate of aspartic acid used for proline fermentation by
Kurthia catenaforma
was traced by using aspartic acid-
U
-
14
C
. The radioactivities of proline and glutamic acid increased with the disappearance of aspartic acid. After 40 hr, aspartic acid disappeared from the medium and radioactive α-ketoglutaric acid was detected. The radioactivity of proline reached 44% of aspartic acid radioactivity at 40 hr. The specific radioactivities of these amino acids and of α-ketoglutaric acid supported the notion that proline is produced mainly from aspartic acid via α-ketoglutaric acid and glutamic acid. Since the levels of glutamic acid dehydrogenases (EC 1.4.1.2 and EC 1.4.1.4) were low in this organism, it appears that the nitrogen atom of aspartic acid enters proline by the action of aspartate aminotransferase (EC 2.6.1.1). The mechanism of proline production is discussed on the basis of the role of aspartic acid in this fermentation.
Stable Reagent for the Detection of Antibody to the Specific Fraction I Antigen of
Yersinia pestis
Authors: Rust James H. , Berman Sanford , Habig William H. , Marshall John D. , Cavanaugh Dan C.
Published: December 2020

A stable hemagglutinating antigen for detection of fraction I (FR-I) antibody of
Yersinia pestis
(
Pasteurella pestis
) is described. The antigen was prepared by sensitizing tanned, pyruvaldehyde-treated sheep erythrocytes (PAT SRBC) with FR-I antigen. Preliminary standardization by titration of each lot of FR-I was required to minimize the effect of molecular heterogeneity of specific FR-I antigen and to eliminate nonspecific reactions caused by the presence of a minor antigenic contaminant. In tests with sera from rabbits, dogs, and humans, FR-I PAT SRBC were as reactive as the previously employed standard antigen, FR-I-sensitized tanned erythrocytes. Fluid suspensions of FR-I PAT SRBC stored at 4 C for 3 months, or lyophilized preparations stored at ambient temperature for 6 months, showed no loss in antigenic activity.
Influence of Serum and Calcium on the Bactericidal Activity of Gentamicin and Carbenicillin on
Pseudomonas aeruginosa
Authors: Davis Starkey D. , Iannetta Antoinette
Published: December 2020

Because calcium was found to be antagonistic in vitro to the activity of colistin and polymyxin B on
Pseudomonas aeruginosa
, the effects of calcium and serum on gentamicin and carbenicillin were also examined. Serum was antagonistic to gentamicin in antibiotic tube dilution tests on five strains of
P. aeruginosa
. Serum was not antagonistic to carbenicillin in tube dilution tests. Physiologic concentrations of calcium antagonized the activity of gentamicin but not carbenicillin. The antagonism observed with gentamicin was less than that previously seen with colistin. The antagonistic effect of calcium and serum was removed by a chelating agent. Gentamicin and carbenicillin may be more active in vivo against
P. aeruginosa
than colistin or polymyxin B.
Immunoperoxidase Localization of Herpes Zoster Virus and Simian Virus 40 in Cell Culture
Authors: Shabo Alan L. , Petricciani John C. , Kirschstein Ruth L.
Published: December 2020

The immunoperoxidase technique was used in an electron microscopy study to localize the virions of herpes zoster virus and simian virus 40 in cell cultures. Intranuclear and intracytoplasmic virions of herpes zoster virus were easily and specifically identified due to intense staining by the finely granular, black reaction product. With simian virus 40, intranuclear virions were not stained, whereas intracytoplasmic particles appeared densely black. There was essentially no background staining. Advantages of this technique over the ferritin-labeled antibody method include simpler preparative procedures for reagents, greater penetrability of the antibody conjugate, and internal amplification which substantially improves the ability to localize sites of antigen-antibody reaction. We believe that the immunoperoxidase method can be successfully applied to a wide variety of problems involving viral antigens.
Metabolism of Pentachlorophenol by an Axenic Bacterial Culture
Authors: Chu Joseph P. , Kirsch Edwin J.
Published: December 2020

A bacterial isolate obtained from a continuous-flow enrichment culture has been shown to metabolize pentachlorophenol as a sole source of organic carbon and energy.
Preparation of Purified Suspensions of
Coxiella burneti
by Genetron Extraction Followed by Continuous-Flow Ultracentrifugation
Authors: Dubois Doria R. , Cutchins Ernest C. , Berman Sanford , Lowenthal Joseph P. , Timchak Robert L.
Published: December 2020

A method for the preparation of purified suspensions of
Coxiella burneti
by Genetron extraction followed by continuous-flow density gradient ultracentrifugation is described. Both phases of the Henzerling strain of
C. burneti
were found in a zone between 53 and 65% (w/w) sucrose. Based on chemical assays, the Genetron zonal rickettsial suspensions were found to be as pure as the rickettsial suspensions which were prepared by the ether extraction method currently in use for producing Q fever vaccines for human use.
Revival and Subsequent Isolation of Heat-Injured Bacteria by a Membrane Filter Technique
Authors: Goff J. H. , Claydon T. J. , Iandolo J. J.
Published: December 2020

Cultures containing mixed flora from raw milk were heated at 62.8 C for 15, 20, 25, and 30 min. Dilutions were filtered through membrane filters, and the filters were incubated on Trypticase soy broth (TSB) and on TSB plus NaCl (TSBS). The TSB count indicated the total population which survived heating and included injured and uninjured cells. The colonies on TSBS indicated the uninjured cells and were marked by perforating the membrane near the colony. This membrane was then transferred to fresh TSB and incubated further. The injured organisms recovered and formed colonies which could be distinguished from previous colonies of uninjured organisms. Transfer counts on TSB were not substantially different from the initial TSB counts at 15, 20, 25, and 30 min of heating.
Radial Immunodiffusion: a Simple and Rapid Method for Detection of Marek's Disease Antigen(s)
Authors: Marquardt W. W.
Published: December 2020

A qualitative radial immunodiffusion technique is described which detects antigen(s) in feathers from live or dead chickens infected with Marek's disease herpesvirus. Antiserum, which is incorporated into a support medium, reacts with antigen(s) in the feather tip producing a radial precipitin ring. Antigen(s) was detected in 93.3% of experimentally inoculated chickens 21 days postinoculation and in 100% of infected birds subsequently tested through 6 weeks. No antigen was detectable in the feathers of uninoculated control chickens. The technique is simple and rapid to perform. Positive tests could be detected after 1 to 2 hours of incubation. Antigen detection by the radial immunodiffusion test correlated well with other criteria of infection. This technique should have application as a laboratory research tool and as an adjunct for a rapid flock diagnosis of Marek's disease.
Tolerance of Staphylococcal Thermonuclease to Stress
Authors: Lachica R. Victor F. , Hoeprich Paul D. , Riemann Hans P.
Published: December 2020

Remarkable tolerance to prolonged heating, prolonged storage, and bacterial proliferation was exhibited by staphylococcal thermonuclease in foods and broth. A purified enzyme preparation added to Brain Heart Infusion broth was unaffected by the growth of five bacterial species. Minimal inactivation was effected by
Bacillus subtilis
. Optimal growth of
Streptococcus faecalis
var.
liquifaciens
caused extensive inactivation of thermonuclease. However, storage at room temperature or the addition of 5% NaCl caused only minimal inactivation.
Evaluation of Assay Methods for Hepatitis-Associated Antigen
Authors: Kissling Robert E. , Barker Lewellys F.
Published: December 2020

Assay methods for hepatitis-associated antigen (HAA) were evaluated for sensitivity, or reproducibility, or both in a series of three trials in which both research and service-oriented laboratories participated. Agar-gel diffusion (AGD) methods were found to be the least sensitive and reproducible of the commonly employed assay methods. Complement fixation (CF) tests were consistently more sensitive than either AGD or counterelectrophoresis (CEP) methods for detection of HAA. With judicious choice of the antibody reagent, sensitivity of CEP techniques was equivalent to CF methods of HAA detection. None of the three major assay methods (AGD, CEP, or CF) compared in this study were capable of consistently detecting HAA when it was present in relatively low concentrations in human serum.
Quantitative Measurement of Precipitating Antibodies in Streptococcal Grouping Antisera by the Single Radial Immunodiffusion Technique
Authors: Harrell William K. , George J. Richard
Published: December 2020

A comparative study was made of the single radial immunodiffusion test and the classical quantitative precipitin test for determining the amount of precipitable antibodies present in streptococcal groups A and C antisera. The potency of 21 group A and 54 group C antisera was determined by both methods; purified group-specific carbohydrates were used as antigens. The coefficient of correlation between the results from the two methods was 0.976 for group A antisera and 0.946 for group C antisera. When the concentration of antigen, the volume of antiserum used, and the depth of the antigen-agar mixture are kept constant, the diameter of the precipitin disc is directly related to the concentration of precipitable antibodies present in the antiserum. The use of the radial immunodiffusion test for evaluating and standardizing streptococcal grouping antisera is discussed as well as the advantages and disadvantages of using a concentrated vaccine for producing these antisera.
Coupled-Enzyme System for Measuring Viral Neuraminidase Activity
Authors: Ziegler Donald W. , Hutchinson Harriet D.
Published: December 2020

A coupled-enzyme assay for determining viral neuraminidase activity is described. All reactants—viral neuraminidase, the initial substrate (fetuin),
N
-acetylneuraminic acid aldolase, lactic acid dehydrogenase, and reduced nicotinamide adenine dinucleotide—are combined in a single cuvette. Thus, in a single coupled system neuraminidase releases
N
-acetylneuraminic acid, which is cleaved to
N
-acetyl-D-mannosamine and pyruvic acid; finally, pyruvate is reduced to lactate as reduced nicotinamide adenine dinucleotide is oxidized. The rate of change of absorbance at 340 nm, as reduced nicotinamide adenine dinucleotide is oxidized, is a measure of the rate of reaction of the coupled system. This procedure, which measures the rate of release of
N
-acetylneuraminic acid by neuraminidase, is an alternate method for those procedures which require multistep, colorimetric determinations.
Uptake of Bacteriophage and Their Subsequent Survival in Edible West Coast Crabs After Processing
Authors: DiGirolamo R. , Wiczynski L. , Daley M. , Miranda F. , Viehweger C.
Published: December 2020

Edible West Coast crabs (
Cancer magister
and
Cancer antennarius
), when in seawater contaminated with coliphage T4, were found to accumulate high titers of this virus. To study the extent of the hazard presented by crabs contaminated with virus, samples of edible crabs were contaminated with coliphage T4 and then processed by boiling. Results indicated that virus in crabs withstood this method of processing. The survival rate varied from 2.5 to 20%, depending upon the processing time. Heat penetration studies showed that, although internal temperature in the crabs was sufficient to inactivate virus, the processing times normally used to cook crabs were not. These results suggest that processed crabs could serve as vectors for the dissemination of virus diseases if the crabs are harvested from a polluted area.
Selective Medium for Hydrogen Sulfide Production by Salmonellae
Authors: Padron A. P. , Dockstader W. B.
Published: December 2020

Triple Sugar Iron Agar does not reveal hydrogen sulfide production by all
Salmonella
organisms nor does it permit clear-cut separation of those nonsalmonellae which produce H
2
S. Numerous media with varied combinations of nutrients, inhibitors, selective agents,
p
H levels, and metal salts were tested for H
2
S production of cultures of
Salmonella, Citrobacter, Edwardsiella, Arizona, Proteus, Providencia, Klebsiella
, and
Enterobacter
. An agar medium has been devised which promotes growth and H
2
S production (generally within 6 hr) by
Salmonella, Arizona
, and
Edwardsiella
but which inhibits hydrogen sulfide production or growth of all other gram-negative organisms tested (including
Citrobacter
) or inhibits both. The use of this medium should facilitate the selection and identification of
Salmonella
.
Effect of Relative Humidity on the Inactivation of Airborne
Serratia marcescens
by Ultraviolet Radiation
Authors: Riley R. L. , Kaufman J. E.
Published: December 2020

Apparatus was designed and constructed in which a bacterial aerosol of known age, particle size, and relative humidity (RH) could be exposed to ultraviolet (UV) radiation of measured intensity for a given period of time and then be sampled quantitatively. Aerosols of
Serratia marcescens
were exposed to UV dosages between 96.0 and 0.75 (μw-sec)/cm
2
at humidities ranging from 25 to 90%. A sharp decline in the fraction of organisms killed was found at RH values above 60 to 70%. Above 80% RH, there was evidence for reactivation induced by UV. The plot of “log fraction organisms remaining” versus UV dose was curvilinear, suggesting noncompliance with the monomolecular law of reaction velocity, but the Bunsen-Roscoe law of reciprocity between time and intensity of UV exposure was demonstrated to hold. These results could be accounted for by postulating the presence in the aerosol of two populations of organisms with different sensitivities to UV, each individually obeying the monomolecular law of reaction velocity. The data amplify existing information on the relationship between UV disinfection of airborne organisms and RH. In the middle range of humidities, the sensitivity of the organisms to UV was greater than would be expected from published reports.
Dry Heat Inactivation of
Bacillus subtilis
var.
niger
Spores as a Function of Relative Humidity
Authors: Brannen J. P. , Garst D. M.
Published: December 2020

Dry heat sterilization of
Bacillus subtilis
var.
niger
spores at 105 C is enhanced in the relative humidity range 0.03 to 0.2%. D-values of 115 and 125 C are predicted by a kinetic model with parameters set from 105 C data. These predictions are compared to observations.
Bacterial Degradation of Benzyl Isothiocyanate
Authors: Tang Chung-Shih , Bhothipaksa Kalong , Frank Hilmer A.
Published: December 2020

Bacteria that degrade benzyl isothiocyanate to benzylamine and hydrogen sulfide were isolated from papaya pulp homogenate by enrichment culture techniques. These organisms were identified as members of
Enterobacter cloacae
.
Scanning Electron Microscopy of Microbial Cells on Membrane Filters
Authors: Todd R. L. , Kerr T. J.
Published: December 2020

Scanning electron micrographs of a
Pseudomonas
species,
Staphylococcus aureus
, and
Bacillus subtilis
on two membrane filtration systems are compared.
Improved Antihyaluronidase Test Applicable to the Microtitration Technique
Authors: Murphy Richard A.
Published: December 2020

The incorporation of India ink into the substrate solution in a standard antihyaluronidase test has facilitated the reading of end points in the standard tube dilution test and has made possible an antihyaluronidase microtiter test.
Gas-Volume Measurement System for Evaluating Effectiveness of Antimicrobial Compounds
Authors: King A. D. , Stanley W. L. , Bolin H. R.
Published: December 2020

Yeast spoilage was followed by measuring gas volume produced inside a sealed bag of inoculated fruit. Volume of gas produced correlates with plate counts.
Tetrazolium Agar Overlay in Test for
Mycoplasma pneumoniae
Authors: Woods Larry L. , Smith Thomas F.
Published: December 2020

In this rapid presumptive test for
Mycoplasma pneumoniae
, subculture is not required, and tetrazolium reduction is evident in 1 hr or less.
Cellulases of
Thermomonospora fusca
and
Streptomyces thermodiastaticus
Authors: Crawford Don L. , McCoy Elizabeth
Published: December 2020

The cellulases of
Streptomyces thermodiastaticus
(strain 2Sts) and
thermomonospora fusca
(strain 190Th) were produced with carboxymethyl-cellulose (CMC) serving as the carbon source during growth. Both cellulases act by random internal hydrolysis of the CMC chain, producing cellobiose, glucose, and intermediate length oligosaccharides. Cellobiase was not detected in culture filtrates produced under these conditions.
Technique and Apparatus for Rapid and Inexpensive Enumeration of Bacteria
Authors: Sharpe A. N. , Dyett E. J. , Jackson A. K. , Kilsby D. C.
Published: December 2020

A foot-operated diluter/dispenser and a projection viewer were developed for use with a rapid bacterial counting technique employing agar droplets. The equipment allows the advantages of the technique to be properly realized and assists many conventional bacteriological tests which may be made at the same time. Significant cost and labor savings are made, with reductions in incubation time, incubator space, and preparative work.
Pneumococci Producing Beta Hemolysis on Agar
Authors: Lorian Victor , Popoola Bodun
Published: December 2020

Fifty-six strains of pneumococci were studied for hemolysis on blood-agar Twenty-two (39%) of these strains produced beta hemolysis on agar containing horse red cells, six (11%) were beta hemolytic for sheep cells, and none lysed human or rabbit red cells. The substance producing beta hemolysis appeared after 24 hr of anaerobic incubation. Subsequent exposure to air at low temperature (6 to 20 C) for 48 hr was needed to activate it. There was no relation between serological type and beta hemolysis production. This substance appears to be different from the pneumococcal hemolysin previously described.
Machine for Automatic Bacteriological Pour Plate Preparation
Authors: Sharpe A. N. , Biggs D. R. , Oliver R. J.
Published: December 2020

A fully automatic system for preparing poured plates for bacteriological analyses has been constructed and tested. The machine can make decimal dilutions of bacterial suspensions, dispense measured amounts into petri dishes, add molten agar, mix the dish contents, and label the dishes with sample and dilution numbers at the rate of 2,000 dishes per 8-hr day. In addition, the machine can be programmed to select different media so that plates for different types of bacteriological analysis may be made automatically from the same sample. The machine uses only the components of the media and sterile polystyrene petri dishes; requirements for all other materials, such as sterile pipettes and capped bottles of diluents and agar, are eliminated.
Distribution of Enzymes Forming Polysaccharide from Sucrose and the Composition of Extracellular Polysaccharide Synthesized by
Streptococcus mutans
Authors: Robrish Stanley A. , Reid William , Krichevsky Micah I.
Published: December 2020

The distribution of polysaccharide-forming activity from sucrose was investigated in cultures of three strains of
Streptococcus mutans
by using an assay which conveniently determines total polysaccharide. The enzymatic activity for polysaccharide formation from sucrose is almost exclusively extracellular. The ratio of the fructan to glucan in the polysaccharide differs among the three strains investigated. The enzymatic activity for the formation of polysaccharide from sucrose has been shown to be bound to the cell-free polymer itself.
Inhibition of Fungal Growth in the Cultural Isolation of Mycobacteria
Authors: Merkal R. S. , Richards W. D.
Published: December 2020

Antifungal antibiotics were compared to determine their usefulness in primary mycobacterial cultures. Amphotericin B was found to be more effective in preventing fungal growth from bovine fecal specimens than were cycloheximide, nystatin, and tetracycline. Amphotericin B did not affect the growth rate of the following
Mycobacterium
species:
M. avium, M. bovis, M. intracellulare, M. paratuberculosis, M. phlei
, or
M. tuberculosis
, but it inhibited the growth of
M. fortuitum
. There was no observable effect on numbers of colonies of
M. paratuberculosis
on primary isolation from fecal specimens. It is recommended that, for the primary isolation of pathogenic mycobacteria from specimens likely to contain fungi, the inoculum should be pretreated with benzalkonium chloride, followed by mixing with amphotericin B or inoculation onto media containing amphotericin B.
Automated Complement Fixation with Low Reagent Consumption
Authors: Olitzky I.
Published: December 2020

A microvolume automated (continuous-flow) system for the detection of complement-fixing antigen or antibody was evaluated. The model complement fixation test used was the detection of deoxyribonucleic acid antibody, and comparisons were made with a manual procedure. An “automatic two-dilution” feature of the apparatus was not used because of the clinical need for antibody titers. The system proved useful for the detection and estimation of anti-deoxyribonucleic acid antibody in patients with systemic lupus erythematosus and, indeed, accomplished this with low reagent consumption, a useful feature not available in “older” continuous-flow complement fixation systems.
Epidemiology of
Pseudomonas aeruginosa
in a Burns Hospital: Evaluation of Serological, Bacteriophage, and Pyocin Typing Methods
Authors: Edmonds Paul , Suskind Raymond R. , Macmillan Bruce G. , Holder Ian A.
Published: December 2020

In a retrospective study 36 cultures of
Pseudomonas aeruginosa
, isolated from patients with fatal
Pseudomonas
burn wound sepsis and from burned patients with nonfatal
P. aeruginosa
infections, were used to evaluate the consistency and reliability of serological, phage, and pyocin typing as epidemiological tools. Frequency distributions of positive reactions were analyzed by a computer in a 3-way chi-square test, and a high degree of consistency was demonstrated for each method. From these data, 75% of the cultures were differentiated by serological, 90% by phage, and 100% by pyocin typing. There was no significant difference among organisms isolated from fatal cases of burn wound sepsis and organisms from patients with nonfatal infections (χ
2
= 0.3418;
P
= 0.9870). The combined typing system was a sensitive and reliable epidemiological tool for intraspecific differentiation of
P. aeruginosa
.
Epidemiology of
Pseudomonas aeruginosa
in a Burns Hospital: Surveillance by a Combined Typing System
Authors: Edmonds Paul , Suskind Raymond R. , Macmillan Bruce G. , Holder Ian A.
Published: December 2020

For 3 months, 259 cultures of
Pseudomonas aeruginosa
isolated from nonpatient environmental sources and 262 cultures from 16 infected patients in the Intensive Care Unit (ICU) of Shriners Burns Hospital were typed by a combined system with a high degree of reliability. Sinks were major sources of environmental contamination. Serotypes 1 and 2 were the predominant types found in patients, and they were most prevalent among typable strains from sinks. Strain designations were made on the basis of similarities in data from serological and phage typing. All nontypable strains were typed by pyocin production. Two infected patients carried different strains of
P. aeruginosa
that remained the same type for 45 days, even though their beds in ICU were approximately 6 feet apart. Cross-contamination from patient to patient and spread of infection by nursing personnel were eliminated as major modes of transmission because nasopharyngeal swabs, hair samples, and hands of nursing staff were consistently negative. Splashing of water from contaminated sinks to fomites was suggested as a possible mode of transfer for this infectious agent.
Reliability of the Kirby-Bauer Disc Diffusion Method for Detecting Methicillin-Resistant Strains of
Staphylococcus aureus
Authors: Drew W. Lawrence , Barry A. L. , O'Toole Richard , Sherris John C.
Published: December 2020

The resistance of
Staphylococcus aureus
to methicillin and related drugs can be reliably determined by using the Kirby-Bauer method of susceptibility testing if the incubation temperature is 35 C or below, but resistance may be missed at 37 C. The 1-μg discs of oxacillin and nafcillin or the 5-μg discs of methicillin may be used for this purpose but not the 1-μg discs of cloxacillin. The latter fail to discriminate between sensitive and resistant staphylococci by zone measurement; some resistant strains of staphylococci may show larger zones of inhibition than sensitive strains. Stability of these antibiotic-containing discs was studied under conditions of temperature and humidity variation that might be encountered in a clinical laboratory refrigerator. Oxacillin discs were the most stable and are to be preferred for susceptibility testing. Nafcillin discs were less stable, and methicillin discs lose their potency rapidly unless carefully stored in a refrigerator with a desiccant.
Tremorgenic Toxin from
Penicillium verruculosum
Authors: Cole R. J. , Kirksey J. W. , Moore J. H. , Blankenship B. R. , Diener U. L. , Davis N. D.
Published: December 2020

A new mycotoxin that produces severe tremors and acute toxicity when administered orally or intraperitoneally (ip) to mice and 1-day-old cockerels was obtained from a strain of
Penicillium verruculosum
Peyronel isolated from peanuts. The ip 50% lethal dose (LD
50
) of this tremorgen was 2.4 mg/kg in mice and 15.2 mg/kg in chickens. Orally administered LD
50
values for the toxin were 126.7 mg/kg in mice and 365.5 mg/kg in chickens. The trivial name “verruculogen” is proposed for this tremorgenic mycotoxin. Physical and chemical characteristics of the mycotoxin are described.
Severe Oral Lesions in Chickens Caused by Ingestion of Dietary Fusariotoxin T-2
Authors: Wyatt R. D. , Weeks B. A. , Hamilton P. B. , Burmeister H. R.
Published: December 2020

Fusariotoxin T-2 is a mycotoxin produced by
Fusarium tricinctum
which was implicated in moldy corn toxicosis of farm animals. Graded concentrations of dietary fusariotoxin T-2 (0, 1, 2, 4, 8, and 16 μg/g, respectively) were given to groups of 40 chickens. Raised yellowish-white lesions on the mouth parts were produced by all concentrations, and the size of the lesions was dose-related. The growth rate was reduced significantly (
P
< 0.05) by concentrations of 4, 8, and 16 μg/g. The mouth fluid of the affected birds contained greatly increased numbers of bacteria, including
Staphylococcus epidermidis
and
Escherichia coli
, which proved avirulent when inoculated into scarified tissue of control birds. Microscopy examinations of the lesions revealed a fibrinous surface layer, intermediate layers containing invaginations filled with rods and cocci, and a heavy infiltration of the underlying tissues with granular leukocytes. These data suggest that the role of fusariotoxin T-2 in field cases of moldy corn toxicosis should be reinvestigated since oral lesions were not mentioned in the original descriptions of the disease. However, the lesions bear some features of those characteristic of the third or septic angina stage of alimentary toxic aleukia, a nutritional toxicosis of humans produced by eating grains infested with
F. tricinctum
.
Demonstration of Rhodanese Activity in Polyacrylamide Gels
Authors: Murphy J. R. , Frankenfeld J. , Calvert J. , Tilton R. C.
Published: December 2020

Rhodanese activity from crude extracts of
Thiobacillus
sp. strain IV-85 was demonstrated in polyacrylamide gels after incubation in the reaction mixture by staining with dichloroindophenol in the presence of methylphenazonium methosulfate. The sensitivity of the staining system was found to be 8 × 10
-7
moles of sulfite.
Improvement of Microbial Assays of Vitamins
Authors: Heed Edward J.
Published: December 2020

A method for the improvement of microbial assays of vitamins, which involves the addition of a surfactant to the incubated test, was developed. This surfactant tends to eliminate bacterial clumping, giving a uniform suspension of single cells, thereby making the turbidity readings less erratic and the actual assay standard curves more closely related to the desired theoretical curve.
Effect of the Medium on Bacteriocin Production Among Strains of
Streptococcus mutans
Authors: Rogers A. H.
Published: December 2020

Bacteriocin production by
Streptococcus mutans
was shown to be influenced by the medium on which the strains were grown, and it is suggested that selected media might be useful in bacteriocin typing.
Three-Tube Method for Screening Stool Cultures for
Salmonella
and
Shigella
Authors: Lee Yhu-Hsiung , Daly A. Kathleen , Thurston Pauline
Published: December 2020

A three-tube method developed is described as a screening test for non-lactose-fermenting organisms isolated from stool cultures. To evaluate the method, 976 strains of gram-negative bacilli were tested. All strains of
Salmonella
and
Shigella
were correctly identified generically.
Vibrio parahaemolyticus
Gastroenteritis in Maryland: Laboratory Aspects
Authors: Molenda John R. , Johnson William G. , Fishbein Morris , Wentz Barry , Mehlman Ira J. , Dadisman Thoburn A.
Published: December 2020

Vibrio parahaemolyticus
was the etiological agent in three food-related epidemics of gastroenteritis in Maryland, during August 1971. These outbreaks involved crab food products. Fifteen isolates of
V. parahaemolyticus
were made which included 11 from patients and 4 from foods. Serotype 04:K11 was the cause of the outbreaks. It was recovered from patients in each outbreak and gave a positive Kanagawa reaction, an indication of enteropathogenicity. Other patient isolates included types 03:K30, 03:K33, and an untypable isolate, all of which were Kanagawa negative. Food isolates included serotypes 03:K30, 02:K28, and two untypable isolates, all of which were Kanagawa negative. The outbreaks reported in this paper constitute the first confirmed foodborne epidemics due to
V. parahaemolyticus
in the United States. Methods for the isolation and identification of
V. parahaemolyticus
are presented, including a procedure for the simple conversion of conventional laboratory media into suitable culture media for this halophilic organism.