bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbiological Evaluation of Pacific Shrimp Processing
Authors: Harrison Janice M. , Lee J. S.
Published: December 2020

Microbiological evaluation of Pacific shrimp (
Pandalus jordani
) processing was made from samples obtained at five key processing points. The microbial count of raw shrimp ranged from 1.3 × 10
6
to 3.0 × 10
6
. The initial microbial flora, in order of predominance, was
Acinetobacter-Moraxella, Flavobacterium, Pseudomonas
, gram-positive cocci, and
Bacillus
species. No yeasts were isolated. Differences in processing practices influenced both microbial count and the shrimp flora. The microbial load, however, always increased after peeling and sorting operations and decreased after cooking, washing, and brining steps. Significantly, the gram-positive cocci were recovered with increasing frequency after each processing step, reaching 76% of the total load in a final product. Most of them, however, were coagulase-negative.
Growth of
Bacteroidaceae
in Stirred Fermentors
Authors: Wahren Ann , Holme Tord
Published: December 2020

The conditions for increasing bacterial yields in cultures of
Bacteroidaceae
by the use of stirred fermentors and
p
H control were investigated by means of three representative species:
Sphaerophorus necrophorus, Bacteroides fragilis
, and
B. melaninogenicus
. A medium containing tryptone, yeast extract, and glucose or sucrose was used. Horse serum had to be added to obtain substantial growth of
B. melaninogenicus
. The optimal
p
H for growth rate and yield was 7.0 to 7.2. Lysis of the bacteria occurred when the glucose (
or sucrose
) was exhausted. The rate of lysis was very high in cultures of
S. necrophorus
, less so in
B. fragilis
and
B. melaninogenicus
. Pleomorphism, manifested as large sperical forms of the bacteria, was observed in the late logarithmic phase of
S. necrophorus
. Great differences in the length of the lag phase and of the mean generation time were found among the three bacterial species. The yield in static cultures of the three species without
p
H control was approximately 0.4 g of dry cells per liter, but was increased, in stirred fermentors with
p
H control, to 3.5 g (
S. necrophorus
), 2.7 g (
B. fragilis
), and 4.3 g (
B. melaninogenicus
) per liter. With an inoculum density of 5 to 10 mg (dry weight) per liter, these yields were obtained in approximately 10 (
S. necrophorus
), 25 (
B. fragilis
), and 35 hr (
B. melaninogenicus
), respectively.
Response of White Mice to Cells and Culture Constituents of
Clostridium perfringens
Authors: Satterlee L. D. , Walker H. W.
Published: December 2020

Broth cultures of
Clostridium perfringens
(ATCC 10543) were fractionated by ammonium sulfate precipitation and Sephadex G-150 chromatography. Components isolated, as well as some enzymes present in the culture, were assayed for toxicity by feeding to white mice. Early work indicated that when a meat-fat-starch slurry, infected with
C. perfringens
, was fed to mice, the intestinal passage time was reduced. By using large numbers of mice as test animals and analyzing the data statistically, we found that
C. perfringens
and several fractions from the culture supernatant significantly affected the mice. A toxic material present in the supernatant was not identifiable as phospholipase C. Phospholipase C and physphorylcholine affected the intestinal passage time of the mice only when large amounts were given. The enzyme, neuraminidase, and another unidentified compound present in the supernatant affected the passage time when very small amounts were fed to mice.
Area-sampling Technique for Quantitative Pharyngeal Cultures
Authors: Johanson Waldemar G. , Pierce Alan K. , Sanford Jay P.
Published: December 2020

An area-sampling device for obtaining quantitative samples of the oropharyngeal bacterial flora is described and illustrative data are presented.
Nonviable Venezuelan Equine Encephalomyelitis Hemagglutinin Prepared from Tissue Cultures by Gamma Radiation
Authors: Reitman Morton
Published: December 2020

Hemagglutinins of Venezuelan equine encephalomyelitis virus were produced in tissue cultures, and the infective virus was rendered nonviable by exposure to gamma radiation.
5-Azacytidine: Microbiological Assay in Mouse Blood
Authors: Pittillo Robert F. , Woolley Carolyn
Published: December 2020

A 6-chloropurine-resistant strain of
Escherichia coli
has been used to develop a microbiological assay for the estimation of 5-azacytidine distribution in mouse tissues.
Determination of Pyrrolnitrin and Derivatives by Gas-Liquid Chromatography
Authors: Hamill Robert L. , Sullivan Hugh R. , Gorman Marvin
Published: December 2020

A gas-liquid chromatographic technique was applied to the separation of pyrrolnitrin and its derivatives. The simultaneous use of a flame detector and an electron capture detector made possible the distinction between the nitro derivatives of pyrrolnitrin and the other metabolites. The metabolites could be readily quantitated with the electron capture detector, offering a much more sensitive assay than the flame detector.
Effect of
p
H and Chelating Agents on the Heat Resistance and Viability of
Salmonella typhimurium
Tm-1 and
Salmonella senftenberg
775W in Egg White
Authors: Garibaldi J. A. , Ijichi K. , Bayne H. G.
Published: December 2020

Supplementation of egg white at
p
H 8.9 with 5 mg of disodium ethylenediaminetetraacetic acid (EDTA) per ml resulted in a kill of
Salmonella typhimurium
Tm-1 of greater than 10
6
per ml after 28 days at 2 C. While at 28 C, supplementation with 7 mg of EDTA per ml resulted in approximately a 10
6
kill in less than 24 hr. Kena supplementation at 40 mg/ml of egg white resulted in a kill of
S. typhimurium
Tm-1 of greater than 10
6
after approximately 60 hr of storage at 28 C. This is in contrast to no reduction in viable count in unsupplemented egg white stored at 2 C and a 100-fold increase in viable count in that stored at 28 C. Supplementation of egg white with EDTA at 7 mg/ml or with Kena at 10 mg/ml also affected the heat resistant characteristics of the two organisms at 52.5 C, reducing the time required to kill 90% of the population (D value) at any
p
H by a factor of 2 to 6. There was a synergistic effect between EDTA and lactic acid when lactic acid was used to adjust EDTA-supplemented egg white to an acidic
p
H (5.3) which greatly decreased the heat resistance of
Salmonella senftenberg
775W (from 100D to D).
Increased Sensitivity of Immunofluorescent Assay for
Salmonella
in Nonfat Dry Milk
Authors: Reamer R. H. , Hargrove R. E. , McDonough F. E.
Published: December 2020

The necessity of developing a quick, sensitive, and reliable test for
Salmonella
in nonfat dry milk (NDM) is evident from the recent tracing of
Salmonella
outbreaks to this product. Normally, coagulation of casein occurs when assaying NDM under regular cultural conditions, raising the possibility of trapped bacteria. After 20 hr of incubation of NDM in preenrichment lactose broth, enrichment was achieved by using Selenite-Cystine Broth. Smears from the enrichment broth were examined by the fluorescent-antibody technique (FAT) with a commercially available polyvalent O globulin conjugated with fluorescein. Standard cultural methods (SCM) were performed for comparison with FAT. Sensitivity of FAT was definitely improved by the use of trypsin. Casein coagulation of NDM can be avoided by addition of trypsin to samples during initial preenrichment in lactose broth. Samples containing approximately one
Salmonella
per 10 g were easily detected by FAT with the use of trypsin-treated samples. The method required only 42 hr to complete. Additionally, the use of trypsin enhanced recovery of
Salmonella
by use of SCM, as evidenced by alteration in the observed coliform to
Salmonella
ratios.
Thermal Injury and Recovery of
Salmonella typhimurium
and Its Effect on Enumeration Procedures
Authors: Clark Carol W. , Ordal Z. John
Published: December 2020

Exposure of
Salmonella typhimurium
7136 to sublethal heating produced a temporary change in the tolerance of the organism to a particular stress medium. After sublethal heat treatment at 48 C for 30 min, greater than 90% of the viable population was unable to reproduce on Levine Eosin Methylene Blue Agar containing 2% NaCl. This sensitivity was dependent on the
p
H of the heating menstruum. In addition, the heated cells displayed a sensitivity to Brilliant Green Agar, Levine Eosin Methylene Blue Agar, Salmonella-Shigella Agar, and Desoxycholate Citrate Agar. Unheated cells displayed a sensitivity to Brilliant Green Agar, Salmonella-Shigella Agar, and Desoxycholate Citrate Agar. When the injured cells were placed in a suitable medium (Trypticase Soy Broth), they recovered and grew at a rate equal to that of normal cells. Recovery was also possible in Nutrient Broth, Lactose Broth, and Lauryl Tryptose Broth. Although recovery of the injured cell occurred in Tetrathionate Broth and Selenite F Broth, they were less than ideal growth media for the organism.
Predominant Catalase-negative Soil Bacteria. III.
Agromyces, gen. n.,
Microorganisms Intermediary to
Actinomyces and Nocardia
Authors: Gledhill William E. , Casida L. E.
Published: December 2020

The occurrence of filamentous, branching, catalase-negative bacteria as a numerically predominant microflora of various soils was demonstrated by using a dilution frequency isolation procedure. The major characteristics of these organisms were those of the order
Actinomycetales.
However, they could not be placed in any of the present genera of this order and, therefore, a new genus,
Agromyces,
was proposed for these organisms. This genus includes catalase-negative, nutritionally-fastidious microorganisms whose cells produce a true branching mycelium that fragments into coccoid and diphtheroid forms. Also, they have an oxidative metabolism, are microaerophilic to aerobic, and contain neither diaminopimelic acid nor lysine as major constituents of the cell wall glycopeptide. The type species would be
Agromyces ramosus,
gen. n., sp. n. The possible importance of these organisms in clarifying certain phylogenetic relationships of the
Actinomycetales
is discussed.

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Biochemical Decomposition of the Herbicide N-(3,4-Dichlorophenyl)-2-Methylpentanamide and Related Compounds
Authors: Sharabi Nagim El-Din , Bordeleau Lucien M.
Published: December 2020

Organisms capable of decomposing N-(3,4-dichlorophenyl)-2-methylpentanamide (Karsil) were isolated, identified, and tested for their ability to hydrolyze this herbicide. Primary products of Karsil decomposition by cells and cell-free extracts of a
Penicillium
sp. were identified as 2-methyl-valeric acid and 3,4-dichloroaniline. The Karsil acylamidase (EC 3.5.1.a aryl acylamine amidohydrolase) was an induced enzyme. It was partially purified and tested for its ability to hydrolyze 25 related compounds. Some relations between the structures of these compounds and their susceptibility to enzymatic hydrolysis were discerned.
Isolation of Shigellae. VII. Comparison of Gram-Negative Broth with Rappaport's Enrichment Broth
Authors: Taylor Welton I. , Schelhart Dorothy
Published: December 2020

Efficacies of Gram Negative Broth (GN) and Rappaport's Enrichment Broth (RE) were compared for detection of enteric pathogens from clinical specimens. Whereas direct streaking on four plating media found 57% of the salmonellae, GN found 80% and RE found 92% of the 157 isolates. By contrast, direct streaking found 87% of the shigellae whereas GN detected 93%, but RE found only 20%. RE produced 35% more
Salmonella
-positive plates than GN did, which resulted in a 15% increase in isolates. Statistically, RE proved to be significantly better than GN. The unsuitability of RE for shigellae, however, dictates that, if only one enrichment broth is to be used, GN must be that choice, but that maximal isolations of all enteric pathogens should result from the use of both RE and GN. Of the four plating media, Xylose Lysine Deoxycholate Agar detected 90% of the salmonellae and 85% of the shigellae. Salmonella-Shigella Agar detected 72 and 43%, respectively, and Levine Eosin Methylene Blue Agar found 45 and 55%. Bismuth Sulfite Agar detected only 22% of the salmonellae and found no shigellae. The performance of all of the plating media was enhanced by enrichment, but RE was especially effective for salmonellae when compared to GN.
New Approach for the Evaluation of Antimycobacterial Drug Combinations In Vitro (the Laboratory Model Man)
Authors: Stottmeier K. D. , Woodley C. L. , Kubica G.P.
Published: December 2020

An attempt was made to study quantitatively the antimicrobial effect of combinations of commercially available antituberculosis drugs and antibiotics on the growth of multiple drug resistant strains of
Mycobacteriunt intracellulare
under simulated in vivo conditions. Combinations of erythromycin, isomiazid, methenamine, or exacillin eliminated populations of
M. intracellulare
when drug combinations in concentrations achievable in man were kept in contact with the organism for 10 hr daily. Although combinations of INH and rifampin failed to eliminate populations of
M. intracellulare
this pair seemed to be the most effective two-drug combination available. The requirement for successful treatment of drug-resistant mycobacterioses is the selection of an effective drug regimen and the maintenance of combined action of all drugs in the serum for approximately 10 hr daily. An in vitro model is described which enables the bacteriologist to design an effective combination of drugs and to measure its efficiency under simulated in vivo conditions.
In Vitro Activity of Coumermycin A
1
Against
Mycobacterium tuberculosis
var.
hominis
Authors: Duma Richard J. , Warner John F.
Published: December 2020

Coumermycin A
1
exhibited in vitro activity against eight strains of
Mycobacterium tuberculosis
var.
hominis.
All eight strains were inhibited by levels of 2.5 μg/ml, and six of the eight strains were inhibited by levels of 0.3 μg/ml or less.
Production of Luteoskyrin, a Hepatotoxic Pigment, by
Penicillium islandicum
Sopp
Authors: Ueno Yoshio , Ishikawa Ichijiro
Published: December 2020

Various factors affecting the yields of luteoskyrin, a hepatotoxic mycotoxin, and related pigments in the liquid medium were studied. Maximal yields of luteoskyrin (0.13% by isolation) and of other pigments were attained in the late phase of the cultivation. The yield of the pigment was increased by supplying malt extract, malonic acid, glutamic acid, or asparagine. A useful material for preparation of
14
C-labeled luteoskyrin was 2-
14
C-malonate.
Automatic Assessment of Respiration During Growth in Stirred Fermentors
Authors: Ribbons Douglas W.
Published: December 2020

An apparatus for the continuous and automatic measurement of respiration during growth of micro-organisms in stirred aerated culture is described. The effluent atmosphere from the culture vessels is passed through commercially available oxygen and carbon dioxide gas analyzers, and their electrical output is fed to a multipoint recorder. The apparatus has been used to measure the respiration of
Escherichia coli, Pseudomonas aeruginosa, Bacillus thuringiensis,
and
Methylococcus capsulatus
during growth on complex and defined media. In addition,
p
H values and dissolved oxygen concentrations were measured. Growth of
P. thuringiensis
in glucose-limited media showed unexpected interruptions in the oxygen consumption curves which resembled diauxic growth; growth of
B. thuringiensis
in complex media showed similar discontinuities of respiration. These results are explained as the sequential utilization of preferred substrates which, in the case of
P. aeruginosa
were provided as transient intermediates of glucose.
Bacteriophage Typing of
Salmonella
. I. Isolation and Host Range Study of Bacteriophages
Authors: Ibrahim Abdel Aziz E.
Published: December 2020

A series of bacteriophages, lytic for bacteria belonging to the genera
Escherichia
and
Salmonella,
were isolated. The phages were isolated from fecal samples, intestinal contents of turkey poults, and carrier cultures of
S. typhimurium, S. typhimurium
var
copenhagen, S. heidelberg,
and
E. coli.
The feasibility of using different habitats as sources of
Salmonella
phages was evaluated. The carrier cultures were the most promising source for phages active on the serotypes for which the phages were sought. A host range study of the isolated phages was made. Eight phages were selected to develop a phage typing scheme for
S. typhimurium, S. typhimurium
var
copenhagen,
and
S. heidelberg.
Rat Pyelonephritis Model Suitable for Primary or Secondary Screening
Authors: Burrous S. E. , Cawein J. B.
Published: December 2020

A rat
Proteus
and
Escherichia
pyelonephritis model is described in which (i) reproducible chronic infections are achieved and (ii) the efficacy of clinically effective agents is reliably demonstrable with five rats in 17 days. It can serve as a primary screen in which one technician can evaluate 180 compounds per month with 900 rats. The manner of inoculation will inherently allow the study of and distinction between metabolism which is peculiar to infection and that which is characteristic of trauma and healing in general for the elucidation of chemical correlations with effective therapy.
Production of Peptide Ergot Alkaloids in Submerged Culture by Three Isolates of
Claviceps purpurea
Authors: Amici A. M. , Minghetti A. , ScottI T. , Spalla C. , Tognoli L.
Published: December 2020

Three strains of
Claviceps purpurea
(Fr.) Tul., isolated from sclerotia grown on rye, produce under submerged conditions ergocryptine and ergotamine, ergocornine and ergosine, and ergocristine, respectively. All of the strains either lacked the ability to produce conidia or formed them sparingly, but they accumulated large quantities of lipids and sterols. The fermentations are typically divided into two phases. The first is characterized by the rapid utilization and exhaustion of the phosphate contained in the medium, rapid uptake of ammonium nitrogen and of citric acid, rapid growth, and low alkaloid production; the second phase is characterized by slower growth and by a marked accumulation of lipids, sterols, and alkaloids.
Effectiveness of Therapy with a Multistranded Synthetic Polynucleotide Complex Against a Murine Sarcoma Virus
Authors: Pearson John W. , Turner Willie , Ebert Paul S. , Chirigos M. A.
Published: December 2020

A known interferon stimulator, polyriboinosinic acid:polyribocytidylic acid (rI:rC), was shown to have a protective effect against a highly tumorigenic variant of the murine sarcoma virus (Moloney) designated as (MSV-PV). Mice treated intraperitoneally with different regimens of rI:rC survived significantly longer than untreated controls. The treatment was effective whether the infection with MSV-PV was intraperitoneal or intracerebral. The antiviral effectiveness of rI:rC was demonstrated by marked reduction of viral replication. The kinetic study of interferon induction by rI:rC showed a peak titer of interferon occurring at 18 hr after injection, followed by a rapid decrease in titer by 24 hr.
Complement-Fixing Antigen from BHK-21 Cell Cultures Infected with Lymphocytic Choriomeningitis Virus
Authors: Brown William J. , Kirk B. E.
Published: December 2020

Infection of BHK-21 cells with lymphocytic choriomeningitis (LCM) virus resulted in the production of significant titers of complement-fixing (CF) antigen. The antigen was spontaneously released from the cells, but the highest titer of 1:16 was recovered by disruption of the infected cells by freeze-thawing in tryptose phosphate broth. The antigen could be partially separated from infectious virus by centrifugation. Furthermore, it was possible to detect LCM virus infection of cell cultures by the production of the CF antigen, but this method proved less sensitive than titration by intracerebral inoculation of mice. The CF antigen from cell cultures was at least as sensitive and specific as the reference antigen prepared from infected guinea pig spleen.
Comparison of Stainless-Steel Closures and Cotton Plugs in Maintaining Contamination-free Medium in Circulating Air
Authors: Sutter Richard P.
Published: December 2020

Culture flasks capped with stainless-steel closures became contaminated when incubated in circulating air. Cotton plugs prevented this contamination.
Selection of Media for the Isolation of Common Bacterial L-Phase Organisms from a Clinical Specimen
Authors: Nimmo Lynn N. , Blazevic Donna J.
Published: December 2020

The L-phase of 13 bacteria commonly associated with disease were induced by penicillin and inoculated into various solid and broth media; their growth was recorded for a period of 14 days. Plates containing highly purified agar and sucrose as the stabilizing agent and those incubated under aerobic conditions gave the best results. Magnesium seems to be necessary for growth in broth media on primary isolation, although it may not be necessary on multiple transfers after a more stable state has been reached. Growth in broth media is much more difficult to achieve. Reversion is aided by using a higher concentration of agar in plates, by decreasing the sucrose concentration, and by omitting the antibiotics and horse serum. A procedure has been outlined for the routine culture and identification of L-phase organisms from a clinical specimen.
Identification of the
Mima-Herellea
Group of Organisms and Selected Members of the Genus
Neisseria
Authors: Marraro Robert V. , Rheins Melvin S.
Published: December 2020

To determine a rapid and reliable protocol for the differentiation of
Mima polymorpha, M. polymorpha
var.
oxidans, Herellea, Bacterium antitratum, Neisseria gonorrheae
, and other related members of the genus
Neisseria
, reference cultures were examined on a variety of microbiological media. The media were selected because of the typical morphological and biochemical characteristics exhibited by the test organisms and were those media which would be readily available in a microbiology facility. After compiling data obtained from 21,714 observations, an inclusive protocol is presented which has proven to be quite adequate for the identification of these particular gram-negative bacteria.
Selective Culture Medium to Survey the Incidence of
Haemophilus
Species
Authors: Crawford James J. , Barden Louise , Kirkman James B.
Published: December 2020

A culture medium for the selective isolation of
Haemophilus
species is described. Bacitracin and nutritional supplements were incorporated in a rich basal agar medium to which rabbit blood was added to distinguish hemolytic species. Colony counts of seven typed strains of
H. influenzae
on this medium were within practical limits of counts on other media tested for clinical use. The bacitracin medium was as reliable as hemoglobin-agar for detecting
H. influenzae
and more sensitive for detecting other
Haemophilus
species in a clinical survey with the advantage of selectivity.

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Variants of
Serratia marcescens
Induced by Freeze-Drying
Authors: Serv�n-Massieu Manuel , Cruz-Camarillo Ram�n
Published: December 2020

Unusually high numbers of pigmentless variants and sectored colonies in cultures of lyophylized
Serratia marcescens
are reported. Clonal analyses of sectored colonies show the presence of unstable bacteria that continue to sector again when plated. Further analysis of pigmentless variants suggest that pigment formation, oxygen uptake, and the production of an inducible protease are affected.
Oxygen Sensitivity of Various Anaerobic Bacteria
Authors: Loesche Walter J.
Published: December 2020

Anaerobes differ in their sensitivity to oxygen, as two patterns were recognizable in the organisms included in this study. Strict anaerobes were species incapable of agar surface growth at pO
2
levels greater than 0.5%. Species that were found to be strict anaerobes were
Treponema macrodentium, Treponema denticola, Treponema oralis
n. sp.,
Clostridium haemolyticum, Selenomonas ruminatium, Butyrivibrio fibrisolvens, Succinivibrio dextrinosolvens
, and
Lachnospira multiparus
. Moderate anaerobes would include those species capable of growth in the presence of oxygen levels as high as 2 to 8%. The moderate anaerobes could be exposed to room atmosphere for 60 to 90 min without appreciable loss of viability. Species considered as moderate anaerobes were
Bacteroides fragilis, B. melaninogenicus, B. oralis, Fusobacteria nucleatum, Clostridium novyi
type A, and
Peptostreptococcus elsdenii
. The recognition of at least two general types of anaerobes would seem to have practical import in regard to the primary isolation of anaerobes from source material.
Effects of 1-(2-Nitro-1-Imidazolyl)-3-Methoxy-2-Propanol and 2-Methyl-5-Nitroimidazole-1-Ethanol Against Anaerobic and Aerobic Bacteria and Protozoa
Authors: Prince Herbert N. , Grunberg E. , Titsworth E. , DeLorenzo W. F.
Published: December 2020

1-(2-Nitro-1-imidazolyl)-3-methoxy-2-propanol (RO 7-0582) and 2-methyl-5-nitroimidazole-1-ethanol (Metronidazole), substances known to be potent trichomonacides, were shown to inhibit obligate anaerobic bacteria in vitro but were essentially without effect at the doses tested against bacteria capable of growing aerobically. A similar effect was noted in vivo in that both substances exhibited good chemotherapeutic activity against infections produced by three species of anaerobic protozoa but were essentially inactive at the doses tested against three species of aerobic protozoa.
Glycolytic and Related Enzymes in Clostridial Classification
Authors: Kotźe J. P.
Published: December 2020

The activities of 15 glycolytic and related enzymes were determined in clostridia. All contained 1-phosphofructokinase; three of them lacked 6-phosphofructokinase and mannitol 1-phosphate dehydrogenase. Glucose 6-phosphate dehydrogenase was found in six clostridia, thus demonstrating the presence of hexose monophosphate shunt. Only parts of the citric acid cycle were found to be present in most clostridia with an indication of the full cycle in
Clostridium septicum
. The intermediary enzyme activities were used to differentiate between the different clostridia.
Congo Red-Agar Plating Medium for Detecting Pigmentation in
Pasteurella pestis
Authors: Surgalla Michael J. , Beesley Earl D.
Published: December 2020

Ability to detect pigmented and nonpigmented
Pasteurella pestis
is essential in plague research, and is currently dependent on use of the synthetic hemin-agar of Jackson and Burrows. We have devised a new differential medium for this purpose, containing Congo red dye and common, commercially available laboratory media. The ease and simplicity of preparation make the Congo red-agar a practical routine laboratory tool in plague research. These findings, possibly indicating a common binding site for hematin and Congo red, should be useful in efforts to determine the chemical nature of a bacterial component associated with high virulence in
P. pestis
.
Aerobic and Facultative Microflora of Fresh and Spoiled Refrigerated Dough Products
Authors: Hesseltine C. W. , Graves R. R. , Rogers Ruth , Burmeister H. R.
Published: December 2020

The microbial flora of fresh, unsterile, dough products held at refrigeration temperatures was compared with the microbial flora of the same products that had spoiled spontaneously. Various methods based on selective media were used to determine molds, yeasts, and bacteria present. Except for two special cases in which a yeast and
Penicillium roqueforti
induced spoilage, all of the samples deteriorated because of bacterial growth. A total of 1,132 bacterial isolates was subjected to further classification. In the spoiled products, 92% of the isolates belonged to the
Lactobacillaceae
. More than one-half of these (53%) belonged to the genus
Lactobacillus
, and an additional 36% were in the genus
Leuconostoc
. In the genus
Leuconostoc
almost all of the strains (94%) were
L. mesenteroides
. The third most common genus present was
Streptococcus
, represented by 3% of the total isolates. A preliminary taxonomic study of the microflora of refrigerated dough products revealed none of the isolates to be indicators of fecal contamination and none to be forms known to produce toxins. The highest counts encountered in the moist, fresh products were up to 200 million lactic acid bacteria per g in buttermilk biscuits, with a psychrophilic count as high as 4.8 million. In the spoiled samples, the highest total counts were 820 million in buttermilk biscuits. Mold counts were no higher than 1,800, except in the sample ruined by
P. roqueforti
where the count was 130,000 mold colonies.
Accelerated Plaque Formation by Fowlpox Virus in the Presence of Chymotrypsin
Authors: Asch Bonnie B. , Gifford George E.
Published: December 2020

Chymotrypsin enhanced fowlpox virus plaque formation in chick embryo cell cultures. A simplified plaque assay for fowlpox virus is described. Plaques were produced in 3 days when chymotrypsin was included in a serum-free fluid overlay. Plaques were also produced in 5 to 6 days under an agar overlay when a medium containing fetal calf serum was employed. Kinetics of plaque formation were also studied, and it was shown that fowlpox virus plaque diameters grow at a linear rate.
Inactivation of Reovirus Type 2 by a Combination of Chloroform and Moderate Temperature
Authors: Engler Reto , Broome Clarisa
Published: December 2020

The infectivity and hemagglutinins of reovirus type 2 were destroyed at 37 C in the presence of chloroform, whereas no effect of chloroform was noted at 0 C.
Relationship of Aflatoxicosis to
Salmonella gallinarum
Infections of Chickens
Authors: Smith J. W. , Prince W. R. , Hamilton P. B.
Published: December 2020

Aflatoxicosis and
Salmonella gallinarum
exert their effects on the body weight and mortality of chickens without any interaction.
New Technique for Rapid Purification, Entrapment, and Recovery of Enterotoxin A from a Liquid Chamber by Polyacrylamide Gel Electrophoresis
Authors: Tan P. L. , Denny C. B. , Heilman W. R. , Bohrer C. W.
Published: December 2020

Electrophoreis of enterotoxin into a middle liquid section of a polyacrylamide gel column enhances recovery for serological assay.
Transferable Drug Resistance Among
Enterobacteriaceae
Isolated from Cases of Neonatal Diarrhea in Calves and Piglets
Authors: Aden David P. , Reed Norman D. , Underdahl Norman R. , Mebus Charles A.
Published: December 2020

Fecal specimens were collected on 22 different Nebraska ranches and at the Department of Veterinary Science from young calves and pigs with neonatal diarrhea.
Enterobacteriaceae
isolated from these fecal specimens were screened for resistance to tetracycline, streptomycin, sulfamethizole, kanamycin, chloramphenicol, colistin, nitrofurantoin, and nalidixic acid. Of the 92 strains studied, 57 were resistant to one or more of these antimicrobial agents. Resistant strains were obtained from all herds involved in the study. The two most common resistance patterns were tetracycline streptomycin sulfamethizole (22 of 57) and tetracycline (13 of 57). None of the strains were resistant to chloramphenicol, colistin, nitrofurantoin, or nalidixic acid. The 57 resistant strains were studied to determine whether the resistance was transferable. Forty-three of the 57 resistant strains could transfer part or all of their resistance pattern to a drug-sensitive recipient. The 43 R
+
strains were obtained from 17 of the 23 herds studied. Considerable variation was observed between different R
+
strains in the frequency of transfer of resistance to a particular drug. In addition, variation in the frequency of transfer of different resistance determinants in individual R
+
strains was noted.
Salmonella
Types Isolated from the Gulf of Aarhus Compared with Types from Infected Human Beings, Animals, and Feed Products in Denmark
Authors: Grunnet K. , Nielsen B. Brest
Published: December 2020

A 2-year examination for
Salmonella
was conducted in the gulf of Aarhus, which receives waste water from local industries and from about 100,000 inhabitants. An approximately rectilinear relationship is shown between the most probable number of
Escherichia coli
and species of
Salmonella. Salmonella
species can be demonstrated with the same frequency in inlets and outlets of the treatment plants. Data on the distribution of
Salmonella
types in the gulf of Aarhus and in Oeresound outside Copenhagen (1 million inhabitants) in 1966 and 1968 and the distribution in man, animals, and feeding stuff during the period 1960 to 1968 in Denmark as a whole are shown. This indicates that the classical chain of infection (feed stuff-animals-food-man) is without importance in Denmark, and that a great nlumber of the human cases may be due to increasing communication, because severa of the demonstrated types have been found neither in feed stuff nor in animals in this period. We suggest that
E. coli
counts, currently used in examination of waters receiving effluents of streams and sewage treatment plants, should be supplemented at intervals with qualitative
Salmonella
examinations.
Improved Medium for Detecting Deoxyribonuclease-Producing Bacteria
Authors: Smith P. B. , Hancock G. A. , Rhoden D. L.
Published: December 2020

Incorporation of methyl green dye into an agar medium containing deoxyribo-nucleic acid results in an improved medium for detecting deoxyribonuclease-producing bacteria. Use of the dye makes it unnecessary to use acid to demonstrate deoxyribonuclease activity, thus allowing subculture or reincubation of colonies. The improved medium is highly sensitive and can be used for primary isolation of
Staphylococcus aureus
or group A
Streptococcus pyogenes
.
Growth Rate of
Sphaerotilus
in a Thermally Polluted Environment
Authors: Bott Thomas L. , Brock Thomas D.
Published: December 2020

In situ growth of
Sphaerotilus
on microscope slides immersed in a thermally polluted stream was studied. Ultraviolet radiation was used to differentiate between passive attachment of organisms from the water and growth of the organisms on the slides. Colonization of the slides in this environment took place solely by means of swarmer cells. A generation time of 2.3 hr was obtained at a water temperature of 18-22 C.
Differentiation of
Clostridium botulinum
Types A, B, and E by Pyrolysis-Gas-Liquid Chromatography
Authors: Cone R. D. , Lechowich R. V.
Published: December 2020

Vegetative cells and spores of 10 strains of
Clostridium botulinum
representing types A, B, and E were grown in Trypticase-peptone-sucrose-yeast extract (TPSY) medium. Five type E strains were also grown in Multipeptone-sucrose-Nutramino acids (MSN) medium. Lyophilized samples were subjected to pyrolysis-gas-liquid chromatography (PGLC) analysis, and the resulting pyrograms were examined for variations in elution patterns between spores and vegetative cells of types A, B, and E grown in the TPSY medium and spores and vegetative cells of type E grown in the TPSY medium and spores and vegetative cells of type E grown in TPSY and MSN media. Growth and toxin production of all 10 strains of
C. botulinum
were investigated by using a modified dialysis sac culture technique. The dialysate supernatant fluid (DSF) obtained after centrifugation of the 5-day-old cultures from the dialysate was also subjected to PGLC analysis. Control samples consisting of (i) noninoculated DSF, (ii) noninoculated DSF plus partially purified toxin, and (iii) 1.0 mg of partially purified toxin were also analyzed by PGLC. Differences between pyrograms of cultures were suitable for positive identification at the type level but not at the strain level. Pyrograms permitting differentiation were also obtained between spores and vegetative cells as well as between the same cultures grown in different media. The dialysis sac technique was useful in detecting growth but not toxin production of
C. botulinum.
Microbiological Aspects of Ethylene Oxide Sterilization
Authors: Kereluk K. , Gammon R. A. , Lloyd R. S.
Published: December 2020

A specially built thermochemical death-rate apparatus is described which can be used to determine the resistance of microorganisms to ethylene oxide under controlled conditions. The apparatus was designed to provide instantaneous exposure of microorganisms to ethylene oxide and to eliminate variables that could result in errors when death kinetic reaction rates are calculated. The apparatus is used to obtain ethylene oxide resistance data which are useful in evaluating and developing sterilizing cycles for materials with known bacterial concentrations, as well as for calculating probability factors on which a given test condition can be expected to provide sterilization.
Potentially Pathogenic, Nonfermentative, H
2
S-Producing Gram-Negative Rod (1 b)
Authors: von Graevenitz Alexander , Simon Gerald
Published: December 2020

An unnamed, polarly flagellated, nonfermentative, H
2
S-producing gram-negative rod which was isolated from pathological material of 13 adult individuals is described.
Portable Sampler for Microorganisms in Incinerator Stack Emissions
Authors: Armstrong David H.
Published: December 2020

To obtain reliable information on viable microbial cells in incinerator stack emissions, a new sampling device has been developed that will concentrate microorganisms from large quantities of stack emissions into a small quantity of 0.067
m
phosphate buffer. The simple, portable sampler provides a method for qualitative, nonisokinetic sampling, adjustable to isokinetic conditions that will yield quantitative results.
Detection of Agglutinins in Chickens Infected with JM Leukosis Virus
Authors: Zacharia Theodore P. , Sevoian Martin
Published: December 2020

Hemagglutinins for sheep red blood cells were detected in sera from JM virus-infected single-comb White Leghorn (susceptible S line) chickens. The agglutinins were not sedimented at 97,000 ×
g
and were not affected by freezing and thawing, possibly indicating a soluble hemagglutinating factor. Agglutination titers were read in a relatively short period, after 4 hr of incubation at 4 C. The usefulness of this test for quick and low-cost screening of a large number of samples is indicated.
Test Method for Determining the Viricidal Activity of Disinfectants Against Vesicular Stomatitis Virus
Authors: Wright Herbert S.
Published: December 2020

A test method using embryonating chicken eggs for the evaluation of several types of disinfectants as viricides against vesicular stomatitis virus was developed which gave specific, reproducible results.
Procedures for the Assay of Carbenicillin in Body Fluids
Authors: Burnett J. , Sutherland R.
Published: December 2020

The assay of carbenicillin in clinical specimens is complicated by the fact that carbenicillin also contains a small amount of benzylpenicillin, thereby precluding the use of conventional penicillin assay organisms. This report gives details of a microbiological assay method involving the use of a strain of
Pseudomonas aeruginosa
which is very sensitive to carbenicillin but insensitive to benzylpenicillin. The outline of a microassay method with this organism is presented, and a method for the assay of specimens containing mixtures of carbenicillin and other antibiotics is described.
Spoilage Bacteria in Canned Foods
Authors: Lin Chau-Ching , Lin Kuan-Chung
Published: December 2020

Clostridium nigrificans
was found to be a spoilage organism of canned mushrooms in Taiwan. A modified beef extract tryptone iron medium, both in broth and agar form, was designed for the detection and recovery of the organisms. A procedure of simple plate counting method of
C. nigrificans
was established.
Comparative Poliovirus Permeability of Silver, Polycarbonate, and Cellulose Membrane Filters
Authors: Hahn Ricardo G. , Hatlen Jack B. , Kenny George E.
Published: December 2020

Three types of filters, silver, polycarbonate, and cellulose, were evaluated for permeability toward poliovirus suspended in water, salt-containing, and proteinaceous solvents. The ability of virus to pass through cellulose filters depended on the suspending medium; virus did not pass through cellulose filters in either water or salt solution, whereas the use of protein solutions increased filterability. The virus permeability of both the silver and polycarbonate filters was independent of the suspending medium. Apparently, pore size alone determined their permeability toward poliovirus, and electrostatic forces between filters and the particles being filtered did not appear to play a significant role. Both the silver and polycarbonate filters appear to be promising tools for the separation of viruses from contaminating bacteria and fungi.
Plaque Formation by Mumps Virus and Inhibition by Antiserum
Authors: Flanagan Thomas D. , Barron Almen L.
Published: December 2020

Boston and ABC strains of mumps virus produced plaques approximately 1.0 mm in diameter in monolayers of BGM cells. The plaques were circular and either clear or target-like in form. Ricki strain virus produced plaques of similar size and form but, in addition, a red plaque was observed with this agent. The vaccine strain of mumps virus, Jeryl Lynn, produced minute clear plaques approximately 0.3 mm in diameter. Incorporation of diethylaminoethyl (DEAE)-dextran into the overlay medium did not affect the size difference between Jeryl Lynn plaques and those of the other strains. However plaques of the Jeryl Lynn and Ricki strains were more easily visualized when the overlay medium contained 400 μg/ml of DEAE-dextran. Simultaneous titration by plaque formation and roller tube infectivity showed that these two methods were of equal sensitivity. Virus neutralization by antibody was demonstrated by plaque reduction. Rise in antibody titer was observed in sera from human and animal infection, human vaccination, and rabbit immunization.
Serum Antibacterial Activity After Oral Suspensions and Capsules of Triacetyloleandomycin and Erythromycin Estolate
Authors: Saslaw Samuel , Carlisle Harold N.
Published: December 2020

Comparison of serum antibacterial activity against a beta-hemolytic streptococcus and a penicillin-resistant staphylococcus was made in a cross-over study in volunteers after ingestion of oral suspensions and capsules of triacetyloleandomycin and erythromycin estolate. Oral suspensions yielded earlier peak titers, but ultimate peak titers and duration of activity were similar to those observed after ingestion of capsules. Antibacterial activity of serum against both organisms was consistently greater with both erythromycin estolate preparations than with the triacetyloleandomycin preparations. These in vitro data were comparable to observations made previously in monkeys infected with the same organisms, although comparative clinical efficacy in monkeys did not reflect these implied therapeutic differences.
Production of Hydrocinnamic Acid by Clostridia
Authors: Moss C. Wayne , Lambert M. A. , Goldsmith D. J.
Published: December 2020

Hydrocinnamic acid was found in acid extracts of spent growth medium from cultures of
Clostridium sporogenes
. The acid was identified by mass spectrometry and its identity was confirmed by gas chromatography. The acid was produced in relatively large amounts (2 to 3 μmoles/ml of medium) by
C. sporogenes
, toxigenic types A, B, D, and F of
C. botulinum
, and some strains of
C. bifermentans
. Other strains of
C. bifermentans
and strains of
C. sordellii
and
C. caproicum
produced only small amounts (0.1 to 0.4 μmoles/ml) of the acid. The acid was not detected in spent medium from toxigenic types C and E of
C. botulinum
or from 25 other strains representing eight
Clostridium
species. Resting cell suspensions exposed to
l
-phenylalanine produced hydrocinnamic and cinnamic acid; the latter compound probably functions as an intermediate in the metabolism of
l
-phenylalanine.
Modification of the Kaolin Serum Treatment Used in the Hemagglutination-Inhibition Test for California Arbovirus Encephalitis
Authors: Robinson P. R. , Allen M. R. , Marcovici M.
Published: December 2020

Modification of the
p
H of kaolin-serum treatment produces hemagglutination-inhibition test results comparable with the plaque neutralization test in duck embryo tissue culture; the standard treatment does not.
Lethal Effects of Electric Current on
Escherichia coli
Authors: Pareilleux A. , Sicard N.
Published: December 2020

An attempt has been made to use low-voltage alternating current to kill microorganisms such as
Escherichia coli
. The bactericidal effect depends on the energy passing through the suspension and on the time during which the cells are left standing in the medium after the treatment. Most of the toxicity is due to an indirect effect developed with unalterable electrodes in the presence of chlorides in the medium. This method might be applied to eliminate pollution of natural waters.
Positive Fluorescent Treponemal Antibody Reactions in Diabetes
Authors: Hughes M. Kathryn , Fusillo Matthew H. , Roberson Bob S.
Published: December 2020

In a survey of 129 diabetic patients and 142 normal individuals, a significantly higher percentage of positive reactions in the fluorescent treponemal antibody-200 (FTA-200) test was found among diabetic patients than in the normal population. Absorption of all FTA-200-reactive sera with an extract of Reiter's treponeme eliminated most of the positive reactions in sera from diabetic patients, and three of the five positive reactions detected in sera from apparently normal subjects. On immunoelectrophoresis, precipitin bands developed most frequently between the Reiter sorbent and sera from diabetic patients positive in the FTA-200 test. Serum components responsible for FTA reactivity and precipitin reactions against the sorbent were resistant to treatment with mercaptoethanol, suggesting antibody of the IgG class. Cross-reacting antibodies produced in response to normal treponemal flora, and perhaps acquiring enhanced reactivity by means of nonspecific interacting substances in sera peculiar to the altered physiological state of diabetes, are suggested as possible causes of positive reactions of unabsorbed sera. No correlation could be made between age of the diabetic patient, treatment or duration of the disease, and FTA or precipitin reactivity of the patient's serum.
Fluorimetric Technique for Monitoring Changes in the Level of Reduced Nicotinamide Nucleotides in Continuous Cultures of Microorganisms
Authors: Harrison D. E. F. , Chance Britton
Published: December 2020

A metabolite fluorimeter was modified to monitor nicotinamide nucleotides in cells growing in a chemostat culture. By illuminating and collecting fluorescence over a relatively large area of the side of the culture vessel, the noise level was kept low even in highly turbulent cultures. Calibration of the system was by enzymatic assay of samples. Changes in nicotinamide nucleotide of concentration less than 0.1 nmoles/ml could be detected [i.e., less than 10% aerobic/anaerobic response for a cell concentration of 5 mg (dry wt) per ml].
Thermal Inactivation of Newcastle Disease Virus
Authors: DiGioia G. A. , Licciardello J. J. , Nickerson J. T. R. , Goldblith S. A.
Published: December 2020

The rate of destruction of hemagglutinins and infectivity of Newcastle disease virus was determined over a temperature range of 37.8 to 60 C. From the calculated values of δH and δS, it was concluded that inactivation of the hemagglutinating activity and viral infectivity was due to protein denaturation.