bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of Antimicrobial Compounds by Hydrolysis of Oleuropein from Green Olives
Authors: Walter W. M. , Fleming H. P. , Etchells J. L.
Published: December 2020

Oleuropein, an intensely bitter glucoside, was isolated from green olives. Hydrolysis products obtained from oleuropein in sufficient quantity for further tests were: (i) β-3,4-dihydroxyphenylethyl alcohol prepared by acid hydrolysis of oleuropein; (ii) elenolic acid obtained by methanolysis of oleuropein, isolation of the intermediate acetal, and subsequent acid hydrolysis; and (iii) oleuropein aglycone formed by the action of β-glucosidase on the parent glucoside. Mass spectral verification of the isolated compounds and ultraviolet absorption data are given. Oleuropein and its aglycone had similar threshold levels for detection of bitterness, whereas elenolic acid and β-3,4-dihydroxyphenylethyl alcohol were not judged to be bitter.
Antimicrobial Properties of Oleuropein and Products of Its Hydrolysis from Green Olives
Authors: Fleming H. P. , Walter W. M. , Etchells J. L.
Published: December 2020

Oleuropein, the bitter glucoside in green olives, and products of its hydrolysis were tested for antibacterial action against certain species of lactic acid bacteria involved in the brine fermentation of olives. Oleuropein was not inhibitory, but two of its hydrolysis products, the aglycone and elenolic acid, inhibited growth of the four species of lactic acid bacteria tested. Another hydrolysis product, β-3,4-dihydroxyphenylethyl alcohol, was not inhibitory. The aglycone of oleuropein and elenolic acid were much more inhibitory when the broth medium contained 5% NaCl; 150 μg of either compound per ml prevented growth of
Lactobacillus plantarum
. A crude extract of oleuropein, tested by paper disk bioassay, was inhibitory to 3 of 17 species of bacteria screened, none of which were lactic acid bacteria. The acid hydrolysate of the extract was inhibitory to 11 of the bacteria, which included four species of lactic acid bacteria and other gram-positive and gram-negative species. Neither crude preparation was inhibitory to growth of the seven species of yeasts tested. A possible explanation is given for the previously reported observation that heating (3 min, 74 C) olives prior to brining renders them more fermentable by lactic acid bacteria. Results of a brining experiment indicated that oleuropein is degraded to antibacterial compounds when unheated olives are brined.
Mass Propagation of Conidia from Several
Aspergillus
and
Penicillium
Species
Authors: Sansing G. A. , Ciegler A.
Published: December 2020

A rapid technique is described for propagation, harvest, and purification of gram quantities of conidia of five
Aspergillus
and six
Penicillium
species.
Salmonella typhimurium hisG46
(R-Utrecht): Possible Use in Screening Mutagens and Carcinogens
Authors: MacPhee D. G.
Published: December 2020

Salmonella typhimurium
LT2
hisG46
becomes a more sensitive strain for assaying mutagens and carcinogens when it carries the resistance transfer factor R-Utrecht.
Method for Storing
Toxoplasma gondii
(RH Strain) in Liquid Nitrogen
Authors: Smith Ross
Published: December 2020

A simple method for storing the trophozoites of
Toxoplasma gondii
(RH strain) is described. Viability of the parasite was maintained for 160 days.
Field Evaluation of the Gel Diffusion Test for the Diagnosis of Ram Epididymitis Caused by
Brucella ovis
Authors: Myers Donald M.
Published: December 2020

A comparison was made with the microslide gel diffusion technique, the complement fixation test, cultural isolation, and clinical examination in detecting ram epididymitis caused by
Brucella ovis
. The results of the gel diffusion method are shown to be similar to those obtained by the complement fixation test and isolation of
B. ovis
from cultures of semen. The technique offers a reliable diagnostic method adaptable to field use in controlling ovine brucellosis and is more practical.
Comparison of Three Culture Media for Isolation of
Mycobacterium tuberculosis
: a 6-Year Study
Authors: Liu Paul I. , McGregor Douglas H. , Faucher Isabelle , Jinks Willard L. , Miller Lawrence A. , Green Lance , Liu J. Grace
Published: December 2020

Among 2,648 specimens positive on culture for
Mycobacterium tuberculosis
over a 6-year period, 82% grew on Lowenstein-Jensen medium (LJ), 79% on American Trudeau Society (ATS), and 56% on Middlebrook 7H10 (7H10). When these commercial culture media were compared in regard to the number of acid-fast bacilli seen on the original smears, LJ cultures were found to have the highest isolation rates for each smear category, and 7H10 had the lowest rates. Comparing the media from the aspect of number of mycobacterial colonies produced, LJ and ATS had the highest average colony counts, followed by 7H10. These findings were relatively constant over the 6-year period. One possible reason for the low positive rate of 7H10 was the lack of CO
2
enrichment.
Selective Broth Medium for Isolation of Group B Streptococci
Authors: Baker Carol J. , Clark Dorothy J. , Barrett Fred F.
Published: December 2020

A selective medium containing Todd-Hewitt broth, sheep blood, nalidixic acid, and gentamicin sulfate was found to enhance significantly the isolation of group B streptococci from vaginal cultures. Preparation of the medium, which is stable for up to 4 weeks at 4 C, is simple and inexpensive. Use of such a medium should facilitate identification of vaginal colonization with group B streptococci.
Evaluation of the PathoTec “Rapid I-D System”
Authors: Blazevic D. J. , Schreckenberger P. C. , Matsen J. M.
Published: December 2020

The 10 biochemical test strips included in the PathoTec Rapid I-D System were evaluated for accuracy as compared to standard tests and for efficacy in identification of 193 gram-negative bacilli. The test agreement was 100% for oxidase and phenylalanine deaminase, 99% for indole, nitrate, and Voges-Proskauer, 98% for malonate, 97% for lysine decarboxylase, 90% for urease, 84% for H
2
S, and 75% for esculin hydrolysis. Most of the commonly isolated
Enterobacteriaceae
were identified correctly within 4 h. Errors in identification of
Proteus morganii
and
P. rettgeri
occurred because of positive H
2
S tests on the PathoTec strips with these organisms.
Influence of Temperature and Humidity on Microbial, Enzymatic, and Physical Changes of Stored, Pickling Cucumbers
Authors: Etchells J. L. , Bell T. A. , Costilow R. N. , Hood C. E. , Anderson T. E.
Published: December 2020

Pickling cucumbers stored at five temperatures and four relative humidities were examined for growth of eight microbial groups, the activities of two enzyme systems (pectinolytic and cellulolytic), and weight loss. Twenty-four storage tests for 6 days each were conducted during the 2-year study. In general, microbial populations of the eight groups increased rapidly at the higher temperature (>21 C) and humidity (>70%) treatments. Moisture loss of the cucumbers was rapid with combinations of high temperatures and low humidities. The results suggest that the best environmental conditions for storage or transport of cucumbers would be a combination of low temperature (10 C) with high relative humidity (about 95%). These conditions minimized undesirable microbial, enzymatic, and physical changes of stored, pickling cucumbers.
Carbohydrate Metabolism in Lactic Streptococci: Fate of Galactose Supplied in Free or Disaccharide Form
Authors: Lee R. , Molskness T. , Sandine W. E. , Elliker P. R.
Published: December 2020

Phosphorylation of free galactose by lactic streptococci was mediated by an adenosine triphosphate (ATP)-dependent kinase. The phosphoenolpyruvate (PEP) phosphotransferase system (PTS) was involved to a limited extent in transport of the sugar. The conversion of free galactose to glucose also was demonstrated, and uridine diphosphogalactose-4-epimerase was demonstrated to account for this change. Galactose, supplied as lactose, was phosphorylated during transport by means of the PTS with PEP as the phosphate donor. Data also indicated that galactose derived from lactose was catabolized by the glycolytic pathway. Results showed the participation of ATP or PEP, or both, in the phosphorylation of five growth sugars for lactic streptococci, namely, galactose, glucose, lactose, maltose, and mannose. Free galactose was phosphorylated exclusively by ATP except when cells were grown on galactose; in this case, slight involvement of PEP in phosphorylation also was noted. Lactose phosphorylation was much more effective with PEP except when cells were grown on lactose, in which case ATP was equally effective. Glucose was phosphorylated to about the same degree by either ATP or PEP.
Stimulation of Lysine Decarboxylase Production in
Escherichia coli
by Amino Acids and Peptides
Authors: Cascieri T. , Mallette M. F.
Published: December 2020

A commercial hydrolysate of casein stimulated production of lysine decarboxylase (EC 4.1.1.18) by
Escherichia coli
B. Cellulose and gel chromatography of this hydrolysate yielded peptides which were variably effective in this stimulation. Replacement of individual, stimulatory peptides by equivalent amino acids duplicated the enzyme levels attained with those peptides. There was no indication of specific stimulation by any peptide. The peptides were probably taken up by the oligopeptide transport system of
E. coli
and hydrolyzed intracellularly by peptidases to their constituent amino acids for use in enzyme synthesis. Single omission of amino acids from mixtures was used to screen them for their relative lysine decarboxylase stimulating abilities. Over 100 different mixtures were evaluated in establishing the total amino acid requirements for maximal synthesis of lysine decarboxylase by
E. coli
B. A mixture containing all of the common amino acids except glutamic acid, aspartic acid, and alanine increased lysine decarboxylase threefold over an equivalent weight of casein hydrolysate. The nine most stimulatory amino acids were methionine, arginine, cystine, leucine, isoleucine, glutamine, threonine, tyrosine, and asparagine. Methionine and arginine quantitatively were the most important. A mixture of these nine was 87% as effective as the complete mixture. Several amino acids were inhibitory at moderate concentrations, and alanine (2.53 mM) was the most effective. Added pyridoxine increased lysine decarboxylase activity 30%, whereas other B vitamins and cyclic adenosine 5′-monophosphate had no effect.
Presumptive Identification of Group A, B, and D Streptococci
Authors: Facklam R. R. , Padula J. F. , Thacker L. G. , Wortham E. C. , Sconyers B. J.
Published: December 2020

A battery of five tests was used for presumptive identification of the pathogenic streptococci. The non-serological methods included determination of hemolysis for all strains, bacitracin susceptibility for group A streptococci, hippurate hydrolysis by group B streptococci, and bile-esculin reaction for group D streptococci. Enterococcal group D streptococci were differentiated from non-enterococcal group D streptococci by 6.5% NaCl tolerance. Two other categories of streptococci resulted: beta-hemolytic streptococci non-groups A, B, or D; and alpha- or nonhemolytic streptococci, not enterococci, not further identified (viridans streptococci). The tests were used as a battery and not as single entities. In this manner more than 99% of the group A, 99% of the group B, 81% of the beta-hemolytic streptococci non-group A, B, or D, 99% of the group D enterococci, 97% of the group D non-enterococci, and 94% of the viridans streptococci were correctly identified.
Use of Stable, Sensitized Cells in Indirect Micro Hemagglutination Test for Amebiasis
Authors: Farshy David C. , Healy George R.
Published: December 2020

Human “O” cells were fixed with pyruvic aldehyde, treated with tannic acid, and fixed with glutaraldehyde. The cells were sensitized with amoeba antigen and stored in a refrigerator. The sensitized cells were used periodically for the indirect hemagglutination test with a battery of sera from patients with intestinal amebiasis and confirmed and unconfirmed amebic liver abscess, and also from negative controls. The same battery was tested with cells sensitized with different batches of antigen and also with fresh sheep cells. None of the cells showed any reaction with negative control sera. The fixed cells remained sensitive and stable throughout the study. Reproducibility of the titers with the fixed cells within each day and from day to day was satisfactory. The titers with fixed human “O” cells were slightly lower than were the titers with fresh sheep cells. The advantages of using stable, sensitized cells are pointed out.
Control of an Estuarine Microfouling Sequence on Optical Surfaces Using Low-Intensity Ultraviolet Irradiation
Authors: DiSalvo L. H. , Cobet A. B.
Published: December 2020

Ultraviolet light has been investigated as an active energy input for the control of slime film formation on optical surfaces submerged in San Francisco Bay for periods up to 6 weeks. Irradiation of quartz underwater windows was carried out from three positions: (i) exterior to the window, (ii) from directly behind the window, and (iii) from the edge of the window with the ultraviolet (UV) energy refracted through the front of the window. Internally administered irradiation reaching levels of 10 to 30 μW per cm
2
measurable at the glass surface was effective in preventing bacterial slime film formation and settlement of metazoan larvae. When administered from the external position, over one order of magnitude more (500 to 600 μW/cm
2
) UV energy was required to accomplish the same result. Irradiation from the edge position was most promising logistically and was effective in fouling control for 6 weeks. The results provide a preliminary quantitation of the energy requirement for control of the marine microfouling sequence which precedes development of macrofouling communities.
Detection of Bacteremia with Liquid Media Containing Sodium Polyanetholsulfonate
Authors: Hall Marsha , Warren Edward , Washington John A.
Published: December 2020

Two liquid blood culture media, Tryptic soy broth (TSB) and Thiol broth, containing sodium polyanetholsulfonate were compared in 8,654 cultures.
Pseudomonas
and
Corynebacterium
(including
Propionibacterium
) were isolated significantly more frequently (
P
< 0.001) from TSB than from Thiol.
Escherichia coli, Haemophilus
, and Bacteroidaceae were isolated more frequently in TSB; however, the differences were not statistically significant. In no instance was Thiol superior to TSB in detecting bacteremia. In an additional 2,977 cultures, aerobic and anaerobic Vacutainer culture tubes with supplemented peptone broth were inoculated in parallel with TSB and Thiol. Significantly greater rates of detection (
P
< 0.01) in TSB or Thiol were noted with
Pseudomonas, E. coli, Enterobacter
, viridans, and group A streptococci, Bacteroidaceae, and staphylococci.
Isolation of
Acidaminococcus fermentans
and
Megasphaera elsdenii
from Normal Human Feces
Authors: Sugihara Paul T. , Sutter Vera L. , Attebery Howard R. , Bricknell Kenneth S. , Finegold Sydney M.
Published: December 2020

Fecal bacterial cultures from 40 normal humans yielded
Megasphaera elsdenii
from four individuals and
Acidaminococcus fermentans
from 10 individuals, with two individuals having both organisms.
Direct Addition of Liquid Propylene Oxide to Dried Materials for Destruction of Salmonellae
Authors: Tompkin R. B. , Stozek S. K.
Published: December 2020

Propylene oxide added in liquid form to dried materials (e.g., animal by-products) is highly effective for destroying salmonellae.
Rapid Plate Method for the Isolation of Lysogenic Bacteriophages
Authors: Siddiqui A. , Hart E. , Mandagere U. , Goldberg I. D.
Published: December 2020

We have devised a rapid plate method for the detection and isolation of lysogenic phages and have used the procedure to screen 15 strains of
Staphylococcus aureus
. This method should prove applicable to a wide variety of bacterial species and should be especially valuable for those pathogens for which no phage-typing system is available.
Simple Densitometer for Microbiology Laboratories
Authors: Adams D. M. , Barach J. T.
Published: December 2020

A densitometer composed of a microscope and a colorimeter is described. Results obtained with the microscope densitometer and with a standard densitometer compare favorably.
Bacteriophage Typing of
Proteus mirabilis, Proteus vulgaris
, and
Proteus morganii
Authors: Schmidt William C. , Jeffries Charles D.
Published: December 2020

A bacteriphage typing scheme for differentiating
Proteus
isolated from clinical specimens was developed. Twenty-one distinct patterns of lysis were seen when 15 bacteriophages isolated on 8
Proteus mirabilis
, 1
P. vulgaris
, and 1
P. morganii
were used to type 162 of 189 (85.7%)
P. mirabilis
and
P. vulgaris
isolates. Seven phages isolated on 3
P. morganii
were used to type 13 of 19 (68.4%)
P. morganii
isolates. Overall, 84.1% of the 208 isolates were lysed by at least 1 phage at routine test dilution (RTD) or 1,000 × RTD. Fifty isolates, retyped several weeks after the initial testing, showed no changes in lytic patterns. The phages retained their titers after storage at 4 C for several months. A computer analysis of the data showed that there was no relationship between the source of the isolate and bacteriophage type. This bacteriophage typing system may provide epidemiological information on strains involved in human infections.
Detection of Staphylococcal Enterotoxin in Foods
Authors: Reiser Raoul , Conaway Donna , Bergdoll Merlin S.
Published: December 2020

A short procedure for the extraction of staphylococcal enterotoxins from food materials has been developed. The procedure involves extraction of the food at pH 4.5, centrifugation, extraction of the supernatant with CHCl
3
(pH 7.5), extraction of the enterotoxin from the water layer with CG-50 ion exchange resin (pH 5.4 to 5.9), and treatment of the eluate with agar and concentration with Carbowax 20-M. The concentrate was extracted with CHCl
3
, and the water layer was lyophilized. The dried material was dissolved in a 1% trypsin solution and placed on microslides, which were incubated 24 h at 37 C. The time required for enterotoxin analysis was 3 days with microslides and 1 day with the reversed passive hemagglutination technique.
Influence of Incubation Atmosphere on Growth and Amino Acid Requirements of
Streptococcus mutans
Authors: Cowman R. A. , Perrella M. M. , Fitzgerald R. J.
Published: December 2020

The growth response of
Streptococcus mutans
representing antigenic type
a
or
d
in a chemically defined medium was influenced by the oxygen concentration of the growth atmosphere. Under controlled aerobic (1.5% O
2
) conditions these cultures attained a greater density than when the atmosphere contained 0.006% O
2
or less. The growth of
S. mutans
strains representing antigenic types
b
or
c
in the defined medium was independent of the oxygen concentration of the growth environment. Under the conditions used in this study, none of the strains tested could utilize ammonium ion as a sole source of nitrogen for growth. The requirement for certain amino acids and inhibition by other amino acids varied with antigenic type and relative oxygen concentration of the growth environment. Under conditions where the atmospheric oxygen was reduced to 0.0006% O
2
or less, the amino acid requirements of the cultures became either more numerous or more stringent.
S. mutans
strains of type
c
generally required the least number of amino acids, whereas cultures of type
d
had more numerous requirements. Nearly every culture tested under the anaerobic atmosphere was inhibited by one of the branched-chain amino acids, leucine, valine, or isoleucine. Methionine and lysine were also found to be inhibitory, particularly toward the type
c
strains.
Tri-Butoxyethyl Phosphate as a Contaminant in B-D Vacutainers
Authors: Farshy David C.
Published: December 2020

An unknown compound was extracted from serum samples. The compound was studied by gas-liquid chromatography, thin-layer chromatography, and mass spectrometry, and was positively identified as tri-butoxyethyl phosphate. The source of this compound was traced to B-D Vacutainers used to collect blood. The importance of this finding is briefly pointed out.
Colicin Typing of
Shigella sonnei
Authors: Morris George K. , Wells Joy G.
Published: December 2020

The colicin typing method for differentiating epidemic strains of
Shigella sonnei
was evaluated. Forty percent of the strains were untypable, but the method divides 60% of the strains into 15 established colicin types. The method has reasonably good reproducibility, but should not be interpreted with the same degree of confidence as some other characteristics such as serotypes. For this reason, known type strains should be included as controls in each analysis to ensure uniformity of results.
Inhibition of the Metabolism of Streptococci and Salmonella by Specific Antisera
Authors: Larson Steven M. , Charache Patricia , Chen Marianne , Wagner Henry N.
Published: December 2020

Streptococcal and salmonella antisera inhibited carbohydrate metabolism for groups A, B, C, and D streptococci and group E salmonella, as measured by the formation of [
14
C]dioxide from [
14
C]glucose metabolism. For salmonella, the inhibition was type specific since group E salmonella were inhibited only by salmonella E antisera and not by anti-salmonella A or C
1
. For streptococci, quantitative differences were demonstrated, but major cross-reactivity was observed. At high concentrations, the antisera were bactericidal; at more dilute concentrations, for both salmonella and streptococci, carbohydrate metabolism was suppressed, but subculture on chocolate agar showed abundant growth. Cross-reacting antibodies could be absorbed by incubation with either antigen, e.g., streptococcal antisera versus heat-killed salmonella. The results suggest that the radiometric technique can be more sensitive than either capillary flocculation or visual detection of bacterial growth for detecting the inhibition of streptococci and salmonella by specific antibodies. The use of specific antisera may prove useful for bacterial species identification in an automated system for detection of bacterial growth.
Inhibition of Aflatoxin Production and Tentative Identification of an Aflatoxin Intermediate “Versiconal Acetate” from Treatment with Dichlorvos
Authors: Schroeder H. W. , Cole R. J. , Grigsby R. D. , Hein H.
Published: December 2020

In general, aflatoxin production by
Aspergillus flavus
and
A. parasiticus
was greatly reduced in vitro in the presence of the insecticide dichlorvos. Reduction in yield of the toxins was accompanied by the apperance of a previously unidentified orange pigment. Spectral analyses of the pigment and of its methylated and acetylated derivatives indicated the compound to be versiconal acetate (IV). The data suggest that IV is an intermediate in the metabolic cycle that may terminate in the production of aflatoxin or of the versicolorins, or both. Dichlorvos apparently inhibits biosynthesis of the difurano ring structure common to the aflatoxins and the versicolorins.
Two-Hour Embedding Procedure for Intracellular Detection of Viruses by Electron Microscopy
Authors: Doane F. W. , Anderson N. , Chao J. , Noonan A.
Published: December 2020

An embedding method requiring only 2 h to complete and giving excellent ultrastructural preservation has been used for the rapid detection of viruses in tissue cultures. The method has also been applied successfully to mammalian tissue. It provides a rapid technique for identifying viruses isolated in tissue cultures, for screening cultures for adventitious agents, and for examining tissue biopsies for viruses.
Plating Isolation of Various Catalase-Negative Microorganisms from Soil
Authors: Labeda D. P. , Hunt Christina M. , Casida L. E.
Published: December 2020

A procedure using nutritionally minimal media is presented for the plating isolation, but not enumeration, of various catalase-negative microorganisms from soil.
Radioimmunoassay on Polycarbonate Membranes: a Sensitive and Simplified Method for the Detection and Quantitation of Antibody
Authors: Green Richard L. , Scales Roy W. , Kraus Stephen J.
Published: December 2020

A new radioimmunoassay technique is described in which a sampling manifold and polycarbonate filter membranes are used. Antigen-antibody reactions take place on the membranes. The manifold permits the simultaneous running of 30 samples and a rapid wash technique in which the washing solution is introduced into the manifold wells and suctioned off from below. The polycarbonate membrane offers a distinct advantage over the cellulose acetate in that nonspecific protein adsorption is substantially reduced. Antigens employed are whole bacteria or soluble antigen coupled to Sepharose beads and are layered over the membrane surface. A radiolabeled antibody is used to measure the primary antigen-antibody interaction. The sensitivity of the procedure is equal to that of fluorescent antibody tests.
Recovery of Poliovirus from Turbid Estuarine Water on Microporous Filters by the Use of Celite
Authors: Hill William F. , Akin Elmer W. , Benton William H. , Mayhew Charles J. , Metcalf Theodore G.
Published: December 2020

The application of a new step for recovering poliovirus from moderately to highly turbid estuarine water by the filter virus-adsorption technique was investigated. The experiments were conducted under both (i) laboratory-based conditions (200-ml volumes) where the turbidity was controlled and (ii) simulated field conditions (15- to 100-gal volumes) where the turbidity varied depending upon the hydrology of the raw estuarine water. The new step consisted of adding Celite to the turbid water prior to sampling for virus. In the experiments, the pH of the water was first adjusted to 3.5 and then AlCl
3
was added to 0.0005 M. Celite was added to a concentration of 0.01% and mixed thoroughly. Either an HE Cox M-780 microfilter (Cox Instrument, Div. of Lynch Corp., Detroit, Mich.) or an MF-membrane filter (Millipore Corp., Bedford, Mass.) was used as the virus adsorbent. Virus was eluted from the Celite-filter complex in situ at pH 9 with 5× nutrient broth. In the laboratory-based experiments, when turbidity ranged from 5.0 to 30.0 Jackson turbidity units (JTU), virus recovery ranged from 66 to 89%. In the simulated field experiments, when the turbidity ranged from 8.5 to 80.0 JTU, virus recovery ranged from <1 to 74%, depending upon the multiplicity of virus input and the level of turbidity. The new step greatly improved the filtration-flux of turbid water and significantly reduced the premature clogging problem usually observed with microporous filters.
Metabolic Disposition of 2, 4, 6-Trinitrotoluene
Authors: Won William D. , Heckly Robert J. , Glover Donald J. , Hoffsommer John C.
Published: December 2020

Three pseudomonas-like organisms have been shown to metabolically oxidize 2, 4, 6-trinitrotoluene (TNT). Capability for this oxidative dissimilation varied with each organism. Of the three, isolate “Y” was the most proficient, isolate “I” was less, and isolate “II” was the least. For accelerated TNT degradation, addition of glucose or a nitrogenous substance was essential. Complete dissimilation within 24 h by isolate “Y” cultures supplemented with 0.5% yeast extract is presumed since no TNT was detectable.
Dissimilation of Tryptophan and Related Indolic Compounds by Ruminal Microorganisms In Vitro
Authors: Yokoyama M. T. , Carlson J. R.
Published: December 2020

Intraruminal doses of L-tryptophan cause acute pulmonary edema and emphysema in cattle. The D and L isomers of tryptophan and 22 related indolic compounds were incubated with ruminal microorganisms in vitro. Incubation of L-[U-benzene ring-
14
C]tryptophan with ruminal microorganisms for 24 h resulted in 39% of the added radioactivity being incorporated into skatole, 7% into indole, and 4% into indoleacetate (IAA). D-Tryptophan was not degraded to any of these metabolites. The major pathway of skatole formation from L-tryptophan appeared to be by the decarboxylation of IAA. Incubation of [2-
14
C]IAA with ruminal microorganisms for 24 h resulted in 38% incorporation into skatole. L-[5-Hydroxy]tryptophan was degraded to 5-hydroxyskatole and 5-hydroxyindole, whereas 5-hydroxyindoleacetate was degraded to only 5-hydroxyskatole. Incubation of indolepyruvate, indolelactate, and indolealdehyde with ruminal microorganisms resulted in the formation of both skatole and indole. Under similar conditions, indoleacetaldehyde was converted to IAA and tryptophol. The addition of increasing concentrations of glucose (0 to 110 mM) reduced the formation of both skatole and indole from L-tryptophan and resulted in the accumulation of IAA. Antibiotics reduced the degradation of L-tryptophan to skatole and indole, with kanamycin and neomycin particularly effective in reducing the decarboxylation of IAA to skatole.
Antibody Response to a Human Diploid Cell Rabies Vaccine
Authors: Cabasso V. J. , Dobkin M. B. , Roby R. E. , Hammar A. H.
Published: December 2020

An experimentally killed rabies virus vaccine prepared in a human diploid cell strain (WI-38)—Wyeth rabies vaccine (WRV)—was used by various injection schedules in two separate studies to define more closely in human volunteer subjects an effective vaccination schedule for pre- or postexposure immunization, particularly for donors of rabies-hyperimmune plasma. To permit valid comparisons between our results and those of other workers, antibody levels achieved were expressed in terms of international units (IU) per milliliter of serum. Antibody response of previously nonvaccinated persons were only modest after a single dose of WRV, never reaching a level higher than 0.80 IU/ml over a 56-day testing period. Moreover, antibody was not detected at 0.16 IU/ml before the 14th day, either after a single dose or after two doses given 3 days apart. The best response followed four doses of WRV given within 4 weeks. This schedule resulted in the highest rate of seroconversion to the ≥6 IU/ml antibody level required of potential rabies-immune plasma donors. Giving the first vaccine dose in aluminum hydroxide diluent did not enhance the antibody response. There was a definite suggestion in the various injection schedules that higher and more sustained antibody levels were reached when the interval between the first and second vaccine doses was longest. The greater immunogenicity of WRV as compared with duck embryo vaccine was best demonstrated by the fact that a single booster dose of duck embryo vaccine to previously vaccinated individuals resulted in only a sevenfold antibody rise during the following 56 days, whereas a booster dose of WRV elicited a 69-fold rise. Al(OH)
3
in the first dose of WRV had no effect, but the enhancing effect of a longer interval between vaccine doses was noted once again; 20 of 20 subjects who received three doses of WRV with 4 weeks between doses developed good levels of rabies antibody, and 19 exceeded 6 IU/ml.
Short-Chain Acids of
Pseudomonas
Species Encountered in Clinical Specimens
Authors: Moss C. Wayne , Samuels S. B.
Published: December 2020

The short-chain acids of 36 strains of
Pseudomonas
grown on Trypticase soy agar were determined by gas-liquid chromatography. Distinct acid profiles were observed for each of the eight species tested. Propionic, isobutyric, and isovaleric acids were the principal acids detected in media extracts of
P. maltophilia, P. cepacia, P. pseudoalcaligenes, P. diminuta
, and
P. vesiculare
. The presence and relative amounts of the isobutyric and isovaleric acids clearly distinguished
P. maltophilia, P. pseudoalcaligenes
, and
P. cepacia
from other species.
P. diminuta
could be distinguished from
P. vesiculare
by the production of glutaric acid;
P. testosteroni
was the only species tested which produced relatively large amounts of phenylacetic acid.
Energy Dispersion X-Ray Analysis by Scanning Electron Microscopy for Measuring Cellular Elemental Composition in Bacterial Cells
Authors: Greaves H.
Published: December 2020

The use of scanning electron microscopy in conjuction with energy dispersion analysis of X rays is presented as a technique in a novel application to in situ studies of cellular elemental composition. The method has been applied, in the example of its use reported here, to examining the effects of copper-chromearsenic wood preservative on growth and element uptake of selected bacteria in agar cultures.
Isolation, Culture Characteristics, and Identification of Anaerobic Bacteria from the Chicken Cecum
Authors: Salanitro J. P. , Fairchilds I. G. , Zgornicki Y. D.
Published: December 2020

Studies on the anaerobic cecal microflora of the 5-week-old chicken were made to determine a suitable roll-tube medium for enumeration and isolation of the bacterial population, to determine effects of medium components on recovery of total anaerobes, and to identify the predominant bacterial groups. The total number of microorganisms in cecal contents determined by direct microscope cell counts varied (among six samples) from 3.83 × 10
10
to 7.64 × 10
10
per g. Comparison of different nonselective media indicated that 60% of the direct microscope count could be recovered with a rumen fluid medium (M98-5) and 45% with medium 10. Deletion of rumen fluid from M98-5 reduced the total anaerobic count by half. Colony counts were lower if chicken cecal extract was substituted for rumen fluid in M98-5. Supplementing medium 10 with liver, chicken fecal, or cecal extracts improved recovery of anaerobes slightly. Prereduced blood agar media were inferior to M98-5. At least 11 groups of bacteria were isolated from high dilutions (10
-9
) of cecal material. Data on morphology and physiological and fermentation characteristics of 90% of the 298 isolated strains indicated that these bacteria represented species of anaerobic gram-negative cocci, facultatively anaerobic cocci and streptococci,
Peptostreptococcus, Propionibacterium, Eubacterium, Bacteroides
, and
Clostridium
. The growth of many of these strains was enhanced by rumen fluid, yeast extract, and cecal extract additions to basal media. These studies indicate that some of the more numerous anaerobic bacteria present in chicken cecal digesta can be isolated and cultured when media and methods that have been developed for ruminal bacteria are employed.
Enzymatic Production of Urocanic Acid by
Achromobacter liquidum
Authors: Shibatani Takeji , Nishimura Noriyuki , Nabe Koichi , Kakimoto Toshio , Chibata Ichiro
Published: December 2020

To develop an efficient method for the production of urocanic acid, optimal conditions for the production of microbial L-histidine ammonia lyase and for the conversion of L-histidine to urocanic acid by this enzyme were studied. A number of microorganisms were screened to test their ability to form and accumulate urocanic acid from L-histidine.
Achromobacter liquidum
was selected as the best organism. With this organism, enzyme activity as high as 2.0 units/ml could be produced by a shaking culture at 30 C in a medium containing glucose, urea, potassium phosphate, L-histidine, yeast extract, peptone, and inorganic salts. Appropriate addition of a surface-active agent to the reaction mixture shortened the time required for the conversion. A large amount of L-histidine was converted stoichiometrically to urocanic acid in 48 h at 40 C. Accumulated urocanic acid was readily isolated in pure form by ordinary procedures with isoelectric precipitation. Yields of isolated urocanic acid of over 92% from L-histidine were easily attainable. When the culture of
Achromobacter liquidum
was added to DL-histidine, D-histidine and urocanic acid were simultaneously obtained in high yields.
Comparison of Two Liquid Blood Culture Media Containing Sodium Polyanetholesulfonate: Tryptic Soy and Columbia
Authors: Hall Marsha , Warren Edward , Washington John A.
Published: December 2020

In a comparison of tryptic soy broth and Columbia broth, two blood culture media containing sodium polyanetholesulfonate, there were 589 positive cultures (excluding presumed contaminants). The two media were equivalent in performance except for lower detection rates for
Staphylococcus aureus
(
P
< 0.01) and
Pseudomonas aeruginosa
(
P
= 0.05) and a higher detection rate for
Bacillus
(
P
< 0.01) in Columbia broth. No significant differences were noted in time intervals to detection of positivity. Routine subcultures on the 1st and 5th days of incubation provided the initial detection of 18.1% of the positive cultures.
Microbiology of the Frankfurter Process: Salmonella and Natural Aerobic Flora
Authors: Palumbo S. A. , Huhtanen C. N. , Smith J. L.
Published: December 2020

Salmonella senftenberg
775W added to frankfurter emulsion was killed during normal processing in the smoke house when internal product temperature was 71.1 C (160 F) or above. The thermal destruction point of
S. senftenberg
775W in frankfurters (temperature at which no viable cells were detected) was a function of the length of time of the process rather than of the starting number of cells. Heating of frankfurters to 73.9 C (165 F) substantially reduced the total non-salmonella count. For total non-salmonella bacterial flora and salmonella, relatively little thermal destruction occurred below 43.3 C (110 F). The heating step can bring about a 7-log cycle decrease (10
8
to 10
1
/g) of bacteria present in the raw emulsion. The flora of this high-bacteriological-count raw emulsion was predominantly gram-negative rods. Variation in the number of bacteria (both total and salmonella) surviving at various temperatures during processing was attributed to slight variations in the temperature pattern of the smoke house during its operation. An integration process was devised which allowed calculation of exposure to temperatures above 110 F (43.3 C) on the basis of degree-minutes. Plots of degree-minutes versus log of surviving bacteria were linear. The salmonella plot had a greater slope than that of the total non-salmonella flora, indicating that salmonellae are more heat sensitive than the bacterial population as a whole. The predominant bacteria surviving the heating step were micrococci. These micrococci were able to increase in number in or on the frankfurters during storage at 5 C.
Effect of Sodium Nitrite on Toxin Production by
Clostridium botulinum
in bacon
Authors: Christiansen L. N. , Tompkin R. B. , Shaparis A. B. , Kueper T. V. , Johnston R. W. , Kautter D. A. , Kolari O. J.
Published: December 2020

Pork bellies were formulated to 0, 30, 60, 120, 170, or 340 μg of nitrite per g of meat and inoculated with
Clostridium botulinum
via pickle or after processing and slicing. Processed bacon was stored at 7 or 27 C and assayed for nitrite, nitrate, and botulinal toxin at different intervals. Nitrite levels declined during processing and storage. The rate of decrease was more rapid at 27 than at 7 C. Although not added to the system, nitrate was detected in samples during processing and storage at 7 and 27 C. The amount of nitrate found was related to formulated nitrite levels. No toxin was found in samples incubated at 7 C throughout the 84-day test period. At 27 C, via pickle, inoculated samples with low inoculum (210
C. botulinum
per g before processing and 52 per g after processing) became toxic if formulated with 120 μg of nitrite per g of meat or less. Toxin was not detected in bacon formulated with 170 or 340 μg of nitrite per g of meat under these same conditions. Toxin was detected at all formulated nitrite levels in bacon inoculated via the pickle with 19,000
C. botulinum
per g (4,300 per g after processing) and in samples inoculated after slicing. However, increased levels of formulated nitrite decreased the probability of botulinal toxin formation in bacon inoculated by both methods.
Chorioallantoic Membrane Measles: Development and Clinical Evaluation of a New Further Attenuated Measles Vaccine
Authors: Cerini Costantino P. , Arguedas G. Jorge , Hernandez C. Guillermo , Frickey Paul H. , Douglas Anne V.
Published: December 2020

A new, further attenuated measles vaccine, developed by propagation of Edmonston B measles virus in the chorioallantoic membrane in ovo, has been clinically evaluated in children and found to compare favorably with a commercially available product. The vaccine is prepared in chick embryo tissue culture and appears to possess noteworthy stability at 4 C.
Compatibility of Trypsin-Modified Human Erythrocytes in the Rubella Hemagglutination-Inhibition Test Employing Three Serum Treatment Procedures
Authors: Nelson Donald B. , Quirin Edward P. , Inhorn Stanley L.
Published: December 2020

Results of comparative tests using trypsin-modified human type O erythrocytes and cells from newly hatched chickens with three standard serum treatment methods for rubella hemagglutination-inhibition techniques are reported. The kaolin, heparin-manganous chloride and dextran sulfate-calcium chloride methods could all be used with both cell types. Reproducibility with heparin-manganous chloride and dextran sulfate-calcium chloride was excellent with both cell types. Both methods gave generally higher antibody titers than the kaolin procedure. However, the use of human cells resulted in a more sensitive system than chicken cells with all serum treatment methods.
Requirement for and Sensitivity to Lysozyme by
Clostridium perfringens
Spores Heated at Ultrahigh Temperatures
Authors: Adams D. M.
Published: December 2020

The requirement of ultrahigh temperature (UHT)-treated
Clostridium perfringens
spores for lysozyme and the sensitivity of heated and unheated spores to lysozyme were studied. The UHT-treated spores requiring lysozyme for germination and colony formation originated from only a small portion of the non-UHT-treated spore population. This raised a question of whether the requirement for lysozyme was natural to the spores or was induced by the UHT treatments. However, these spores did not require lysozyme for germination before UHT treatment, which confirmed that the requirement for lysozyme had been induced by the UHT treatment. Only 1 to 2% of the spores were naturally sensitive to lysozyme; therefore, the mere addition of lysozyme to the plating medium did not permit the enumeration of all survivors. Treatment of UHT-treated spores with ethylenediaminetetraacetate (EDTA) sensitized the spores to lysozyme and increased by 10- to 100-fold the number of survivors that were detected on a medium containing lysozyme. Under the heating conditions used, spores that were naturally sensitive to lysozyme and spores that required EDTA treatment were equally heat resistant.
Use of Tunable, Pulsed Dye Laser for Quantitative Fluorescence in Syphilis Serology (FTA-ABS Test)
Authors: Kasatiya S. S. , Lambert N. G. , Laurence R. A.
Published: December 2020

A pulsed dye laser was used as an excitation source in a fluorescent treponemal antibody absorption (FTA-ABS) test. A high precision in quantitative fluorescence was obtained with this high-power excitation source coupled to an electronic detection system and a storage oscilloscope by standardization of fluorescence evaluation and through elimination of human error. One 0.4-μs pulse exposure was sufficient to record fluorescence intensity data on the oscilloscope. Absence of fading of fluorescence after repeated excitation permitted multiple readings of the same microscope field. Almost 100% reproducible results were obtained for the FTA-ABS test with 40 samples. Electronic detection of fluorescence and the high sensitivity obtained with laser excitation raise doubts about the relative value of quantitative immunofluorescence in the FTA-ABS test.
Effect of Heat on the Antimicrobial Activity of Brilliant Green Dye
Authors: Moats W. A. , Kinner J. A. , Maddox S. E.
Published: December 2020

Antimicrobial activity of brilliant green dye in Trypticase soy broth (BBL) is reduced and ultimately destroyed by prolonged autoclaving at 121 C. Loss of antimicrobial activity is accompanied by decolorization of the dye. This is consistent with other evidence that antimicrobial activity of brilliant green resides in the colored dye ion. The dye is not decolorized when heated in distilled water or peptone, but is decolorized by heating in glucose, glycine, or sodium dodecyl sulfate, showing that decolorization results from reaction with components of the medium. To ensure optimal results, it is recommended that bacteriological media be sterilized by heat prior to addition of brilliant green dye.
A High-Precision and Large-Capacity Laser Biophotometer
Authors: Marchand A. , Piaud J. J. , Du Pasquier P.
Published: December 2020

A new type of biophotometer is described. Very precise and reproducible measurements of bacterial concentration can be performed at 3-s intervals for each of 32 simultaneously developing bacterial cultures. The large number of results is handled with modern data acquisition and computer-processing techniques.
Immobilized Aspartase-Containing Microbial Cells: Preparation and Enzymatic Properties
Authors: Chibata Ichiro , Tosa Tetsuya , Sato Tadashi
Published: December 2020

The immobilization of asparatase-containing
Escherichia coli
was investigated by various methods, and the most active immobilized cells were obtained by entrapment in a polyacrylamide gel lattice. Other asparatase-containing bacteria were also entrapped by the same method, and the enzymatically active immobilized cells were obtained. The aspartase activity of the immobilized
E. coli
cells was increased nine- to tenfold by autolysis of the cells entrapped in the gel lattice. Enzymatic properties of the immobilized
E. coli
cells were investigated and compared with those of the intact cells. The optimal pH was 8.5 for the immobilized cells and 10.5 for the intact cells. The aspartase activities of immobilized and intact cells were not activated by Mn
2+
, which can activate the immobilized and native aspartases. The heat stability of the immobilized cells was somewhat higher than that of the intact cells. Bivalent metal ions such as Mn
2+
, Mg
2+
, Ca
2+
protected against thermal inactivation of the aspartase activity of the immobilized and intact cells.
Microculture System for Detection of Newcastle Disease Virus Antibodies
Authors: Wooley R. E. , Brown J. , Gratzek J. B. , Kleven S. H. , Scott T. A.
Published: December 2020

A microculture system utilizing cytopathic effect (CPE) and hemadsorption (HAd) end points was effective in determining the level of Newcastle disease virus (NDV) antibodies. The microculture system was of comparable sensitivity to the plaque reduction test for the detection of NDV antibodies. The standards by which the CPE and HAd microculture tests would be considered reproducible were defined. The results indicate that the CPE and HAd microculture tests are reproducible within one twofold dilution.
The Plaque-Antiserum Method: an Assay of Virus Infectivity and an Experimental Model of Virus Infection
Authors: De Flora Silvio
Published: December 2020

Areas of cytopathic effect can be circumscribed in cell monolayers by adding antiserum to the liquid nutrient medium after adsorption of virus. This procedure represents a simple and reliable tool for the titration of virus infectivity and provides an experimental model for studying some aspects of virus infection.
Resistance to Gonorrhea Possibly Mediated by Bacterial Interference
Authors: Kraus Stephen J. , Ellison Neal
Published: December 2020

Two men with no prior history of urethritis failed to develop gonorrhea after sexual exposures to women with genital gonococcal infection. Usual methods of prophylaxis, such as antibiotics or condoms, were not employed. The aerobic bacterial flora of these men's urethras consisted of several bacteria, some of which inhibited the in vitro growth of
Neisseria gonorrhoeae
. The hypothesis is suggested that bacterial interference may have played a role in protecting these men from gonorrhea.