bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship Between Rumen Ammonia Levels and the Microbial Population and Volatile Fatty Acid Proportions in Faunated and Defaunated Sheep
Authors: Males J. R. , Purser D. B.
Published: December 2020

Cheviot wethers were defaunated by using dioctyl sodium sulfosuccinate and were constantly infused with urea to provide 2.87% of the daily N intake. Defaunation resulted in higher rumen dry matter and lower rumen
p
H. The molar per cent propionate was higher in defaunated sheep, whereas the molar per cent butyrate and acetate was lower. Apparent nitrogen digestibility, nitrogen utilization, and nitrogen balance were higher in defaunated sheep when compared with faunated animals. Urea infusion resulted in lower apparent nitrogen digestibility, nitrogen utilization, and nitrogen balance in faunated sheep, but did not affect nitrogen metabolism in defaunated sheep. Rumen ammonia-N levels in defaunated sheep were lower than those observed for faunated animals, and urea infusion into faunated sheep increased rumen ammonia-N levels to a greater extent than did the urea infusion into defaunated animals. Significant correlations were demonstrated between rumen ammonia-N levels and C
2
/C
3
, C
3
/C
4
and C
2
/C
4
volatile acid ratios. From this it was concluded that, as rumen ammonia-N levels increased, there was a shift from propionate to higher proportions of butyrate and acetate.
Use of Glutamic Acid to Supplement Fluid Medium for Cultivation of
Bordetella pertussis
Authors: Lane A. G.
Published: December 2020

The amino acid consumption by
Bordetella pertussis
growing in broth containing casein hydrolysate was examined. Serine, proline, alanine, glycine, aspartate, and glutamate were rapidly consumed, in a manner which suggested that they supplied the energy requirements of the organism; exhaustion of the energy source appeared to be the main factor limiting the yield of cells. There was no correlation between the utilization of individual amino acids and the phase of growth; uptake appeared to depend only upon relative concentrations. Consumption of threonine, phenylalanine, histidine, leucine, and methionine was slight; consumption of valine and lysine was variable, and isoleucine was excreted. The addition of monosodium
l
-glutamate (3 mg/ml) to the broth in shaken flasks increased the cell yield by an average of 43.5%. It had no detectable adverse effect upon the agglutin-producing capacity, agglutinability in antisera versus smooth and rough growth phases, mouse-lethal toxicity, histamine-sensitizing factor potency, or intracerebral protective potency of the culture. Broth supplemented with monosodium
l
-glutamate has been used over a 2-year period to prepare experimental vaccines by both batch and continuous cultivation methods at controlled
p
H; the cell yields obtained from the supplemented broth have been up to 52% higher than those from the basal broth. The use of glutamate to replace a proportion of casein hydrolysate in the broth caused a reduction in the cell yield, an alteration in cell morphology, and reduction in the mouse-lethal toxicity, the histamine-sensitizing factor potency, and the intracerebral protective potency of the cells.
Description of a Viral Agent Found in Blood Obtained from Patients with Infectious Hepatitis
Authors: Hartwell W. V. , Eidenbock Marie P. , Murphy B. L. , Auernheimer A. H.
Published: December 2020

A small, double-stranded deoxyribonucleic acid viral agent (agent Y) has been found in blood from patients with infectious hepatitis. The agent was propagated in chimpanzee liver tissue culture which had been grown and maintained on unheated agamma calf serum. A causal relationship between this agent and the occurrence of human disease cannot be determined from the data presented.
Motile Nocardoid
Actinomycetales
Authors: Sukapure R. S. , Lechevalier Mary P. , Reber H. , Higgins M. L. , Lechevalier H. A. , Prauser H.
Published: December 2020

The properties of 42 strains of nocardoid (nocardioform) bacteria were compared. The results indicate that the organism previously called
Nocardia turbata
does not belong to the genus
Nocardia
nor does it fit into any of the previously described genera.
Influence of
p
H and Aeration on Bacterial Formation of Amylase
Authors: Mazza Luis A. , Ertola Rodolfo J.
Published: December 2020

Amylase production by a
Bacillus subtilis
strain can occur without aeration after reaching the stationary phase of growth, provided the
p
H is controlled.
Agar Dish Isopiestic Equilibration Method for Controlling the Water Potential of Solid Substrates
Authors: Harris R. F. , Gardner W. R. , Adebayo A. A. , Sommers L. E.
Published: December 2020

Maintenance of substrate water potential in petri dishes is achieved by using vapor-pressure controlling, solute-amended agar gel discs attached to the inside of the top halves of the dishes.
Conditions for Production of Ochratoxin A by
Aspergillus
Species in a Synthetic Medium
Authors: Lai Mingtan , Semeniuk G. , Hesseltine C. W.
Published: December 2020

Trace elements were required by
Aspergillus melleus
and
A. ochraceus
, but not by
A. sulphureus
, to grow and to elaborate ochratoxin A. The composition of the medium affected the synthesis of the toxin more than the growth of the mycelium.
Use of Vero Cells for Titration of Rinderpest Virus and Its Neutralizing Antibody
Authors: Mirchamsy H. , Shafyi A. , Bahrami S.
Published: December 2020

Primary bovine embryonic kidney cell was successfully replaced by the green monkey cell line (Vero) for the isolation and seroneutralization of rinderpest virus.
Production of Amylase in Liquid Culture by a Strain of
Aspergillus oryzae
Authors: Kundu A. K. , Das S.
Published: December 2020

The effect of different media and
p
H on the formation of amylase by
Aspergillus oryzae
EI 212 is described. Depending upon the composition of the medium and growth conditions, the fungus was found to secrete α- or β-amylase, or both. Some of the properties of the partially purified α-amylase were found to be different from α-amylases from other sources.
Laboratory Identification of Aeromonads from Man and Other Animals
Authors: Nygaard Genevieve S. , Bissett Marjorie L. , Wood Ronald M.
Published: December 2020

Forty-eight isolates of aeromonads from clinical specimens were studied. The laboratory procedures employed and the results obtained are reported in the hope that they may be of assistance to other workers in the field of diagnostic microbiology. Capability of identifying these organisms in the laboratory will contribute to a better understanding of the role of this group of organisms in human disease as well as in diseases in other animals.
Airborne Stability of Tailless Bacterial Viruses S-13 and MS-2
Authors: Dubovi Edward J. , Akers Thomas G.
Published: December 2020

The effect of relative humidity (RH) on the airborne stability of two small bacterial viruses, S-13 and MS-2, was studied. Poorest recovery of S-13 was obtained at 50% RH. Humidification prior to aerosol sampling significantly increased the recovery of S-13 at RH deleterious to the airborne virus. A commercial preparation of MS-2 suspended in a buffered saline solution showed a rapid loss of viability at RH above 30%, whereas a laboratory preparation containing 1.3% tryptone showed high recoveries at all RH studied. Dilution of the commercial MS-2 into tryptone broth conferred stability on the airborne virus. Humidification prior to sampling significantly reduced the viable recovery from aerosols of commercial MS-2, whereas the laboratory preparation was unaffected.
Characteristics of a New Strain of
Bacillus popilliae
Sporogenic In Vitro
Authors: Sharpe E. S. , Julian Grant St. , Crowell Clarence
Published: December 2020

Conditions are described that led to the isolation of NRRL B-2309M, a strain of
Bacillus popilliae
which sporulates regularly in laboratory culture. Colonies grown on a medium formulated with yeast extract and the ingredients of Mueller-Hinton with phosphate, trehalose, and agar, produced 20% spores in 10 to 12 days. The quantity and kind of yeast extract determine the extent of sporulation, although there are other requirements for optimal growth and sporulation. Spore inocula free of viable vegetative cells are necessary to maintain sporogenicity since asporogenic substrains arise spontaneously on solid and in liquid media. One such substrain, NRRL B-2309N, is also asporogenic in larvae, but lethal, owing to vigorous vegetative growth. Strain B-2309M is infective when vegetative cells or spores are injected into Japanese beetle larvae but fewer spores are formed in vivo than when infections are caused by NRRL B-2309. The characteristics of four related strains of
B. popilliae
are tabulated.
Production of High Titers of Enterotoxins for the Routine Testing of Staphylococci
Authors: Jarvis Audrey W. , Lawrence R. C.
Published: December 2020

The cellophane-over-agar technique has been shown to give high titers of enterotoxins A, B, and C for routine testing of staphylococci for enterotoxigenicity.
Long-Term Preservation of
Anaplasma marginale
in a Liquid Nitrogen Repository
Authors: Love John N.
Published: December 2020

The infectivity of
Anaplasma marginale
was maintained in liquid nitrogen storage throughout a 4-yr test period.
Detection of
Aerobacter aerogenes
by Labeling with Radioactive Phosphorus
Authors: MacLeod Robert A. , White Lloyd A. , Currie J. F.
Published: December 2020

A method for the detection of bacterial cells by labeling with
32
P has been found to be much less sensitive than was previously reported.
Evaluation of Reagent-Impregnated Coagulase-Mannitol Test Strip for Speciation of Staphylococci
Authors: Washington John A. , Yu Pauline K. W.
Published: December 2020

A new coagulase-mannitol reagent-impregnated strip test has been evaluated with 322
Micrococcaceae.
Mannitol fermentation was determined accurately by this test; however, the coagulase reaction was difficult to interpret and was subject to significant error.
Production of Chlorflavonin, an Antifungal Metabolite of
Aspergillus candidus
Authors: Munden J. E. , Butterworth D. , Hanscomb G. , Verrall M. S.
Published: December 2020

Production of chlorflavonin, a new antifungal antibiotic, by strains of
Aspergillus candidus
is described. Two wild strains of the fungus had distinctly different chlorflavonin-producing capabilities. One strain produced 25 μg of chlorflavonin per ml per 4 to 5 days in a pilot scale fermentor with stirring, using a medium containing corn steep liquor and glucose. Production of antibiotic was favored by high rates of agitation-aeration. Crude chlorflavonin was extracted from the whole brew with a hydrocarbon solvent and then purified by recrystallization from benzene and petroleum ether. The overall yield from fermentation brew to pure product was 50%.
Metabolism of Tryptophan by
Pseudomonas aureofaciens
Authors: Hamill R. L. , Elander R. P. , Mabe J. A. , Gorman M.
Published: December 2020

Exogenous tryptophan is metabolized by
Pseudomonas aureofaciens
to yield pyrrolnitrin [3-chloro-4-(2′-nitro-3′-chlorophenyl)-pyrrole], an antifungal agent. The ability of this culture to metabolize tryptophan analogues in a similar manner was investigated by addition of the appropriate compound to the fermentation. Tryptophan precursors and metabolites or nonphenyl-substituted tryptophans had little effect on pyrrolnitrin biosynthesis, but simple derivatives of indole inhibited the production of pyrrolnitrin. Tryptophans substituted at the 4 position decreased pyrrolnitrin production and were converted into the corresponding substituted indoles. Tryptophans substituted at the 5, 6, and 7 position with fluorine or at the 5 and 7 position with methyl yielded new pyrrolnitrin derivatives. Substitution of larger groups (such as chloro, bromo, trifluoromethyl, and methoxy) at these positions led to the formation of the intermediate, amino pyrrolnitrin [3-chloro-4-(2′-amino-3′-chlorophenyl)-pyrrole], with the appropriate new substituent. The trifluoromethyl group at the 6 position of tryptophan prevented chlorination at the 3 position of pyrrolnitrin.
Titration of Cholera Antitoxin in Human Sera by Microhemagglutination with Formalinized Erythrocytes
Authors: Hochstein H. Donald , Feeley John C. , DeWitt Wallis E.
Published: December 2020

Microtiter hemagglutination tests employing formalinized sheep erythrocytes sensitized with either crude or purified cholera toxin were used to assay the cholera antitoxin content of human sera. Comparable results were obtained with either crude or purified toxin-sensitized cells with the exception of two sera that gave unusually high hemagglutination titers with the crude toxin. Sera from 13 convalescent cholera patients showed a high degree of correlation between antitoxin levels as determined in vitro by the hemagglutination test and in vivo by the skin permeability factor neutralization test. Fourfold or greater rises in antitoxin levels between acute and convalescent sera were detected in 9 of 15 patients with bacteriologically proven cholera. No significant increases in titer were observed in 14 cases of noncholera diarrhea. Cholera antitoxin was detected by hemagglutination in only 1 of 33 sera, obtained from eight countries, containing vibriocidal antibodies. Formalinized sheep erythrocytes sensitized with toxin and stored at 4 C in the presence of 1:10,000 thimerosal were stable and sensitive for at least 6 months (the longest time tested).
Haloprogin: a Topical Antifungal Agent
Authors: Harrison E. F. , Zwadyk P. , Bequette R. J. , Hamlow E. E. , Tavormina P. A. , Zygmunt W. A.
Published: December 2020

Haloprogin was shown to be a highly effective agent for the treatment of experimentally induced topical mycotic infections in guinea pigs. Its in vitro spectrum of activity also includes yeasts, yeastlike fungi (
Candida
species), and certain gram-positive bacteria. The in vitro and in vivo antifungal activity of haloprogin against dermatophytes was equal to that observed with tolnaftate. The striking differences between the two agents were the marked antimonilial and selective antibacterial activities shown by haloprogin, contrasted with the negligible activities found with tolnaftate. Addition of serum decreased the in vitro antifungal activity of haloprogin to a greater extent than that of tolnaftate; however, diminished antifungal activity was not observed when haloprogin was applied topically to experimental dermatophytic infections. Based on its broad spectrum of antimicrobial activity, haloprogin may prove to be a superior topical agent in the treatment of dermatophytic and monilial infections in man.
Bacteriological Examination of Commercial Precooked Eastern-Type Turkey Rolls
Authors: Mercuri A. J. , Banwart G. J. , Kinner J. A. , Sessoms A. R.
Published: December 2020

Studies were conducted to ascertain the bacteriological condition of commercially cooked Eastern-type (foil-wrapped-oven roasted) turkey rolls during processing and storage. After 2 weeks at 5 C, numbers of aerobes on the surface of rolls, in slices, and in whole rolls reached levels of from 1 to 10 million per cm
2
or per g. In stored whole rolls, coliform and enterococcus counts ranged, respectively, from about 10,000 to more than 1 million per g and from < 100 to more than 1 million per g. Postcooking processing operations in two plants did not significantly affect the total count of turkey rolls. Eight of 28 rolls obtained after handling and packaging contained coagulase-positive staphylococci.
Method for Extracting Viral Hemagglutination-Inhibiting Antibodies from the Nonspecific Inhibitors of Serum
Authors: Altemeier William A. , Mundon Francis K. , Top Franklin H. , Russell Philip K.
Published: December 2020

Various methods are used to remove nonspecific inhibitors from sera before titering viral hemagglutination-inhibiting antibodies. These methods have several undesirable features; some are tedious and time-consuming, some remove antibody along with nonspecific inhibitors, and different techniques are usually required to remove the nonspecific inhibitors for different viruses. This communication describes a single method that uses diethylaminoethyl-Sephadex to extract the immunoglobulin G antibodies for several viruses from nonspecific inhibitors. The procedure is fast, simple to perform, and removed the nonspecific inhibitors for influenza, Western equine encephalitis, dengue-2, and rubella viruses.
Viremia and Virus Measurements of Rabbit Pox in CV-1 Cells
Authors: Cho Cheng T. , Locke Thomas , Wenner Herbert A.
Published: December 2020

Rabbit pox virus (RPV) produced cytopathic effect (CPE) in five types of cells grown in tissue cultures. The CPE on CV-1 cells was characterized by cell fusion and lysis. The CV-1 line is a useful and sensitive cell culture for measuring concentrations of RPV in blood and tissues of infected rabbits. Viremia was detected between the 2nd and 4th days after parenteral infection. By the 6th and 7th days, the concentration of RPV in various tissues ranged from 10
5-3
to 10
8-5
TCID
50
/g. Cross-reactivity was demonstrated by the fluorescent-antibody technique between rabbit pox, vaccinia, and monkey pox viruses.
Fowl Cholera Immunization in Turkeys
Authors: Brown John , Dawe Donald L. , Davis Richard B. , Foster John W. , Srivastava K. K.
Published: December 2020

Cell fractions of
Pastuerella multocida
(P-1059) were tested as vaccines against fowl cholera in turkeys. These fractions were culture filtrate, cell wall, and cytoplasm. A second culture filtrate preparation made from cells grown on blood-agar rather than the standard medium was also tested along with a “combination” preparation made by recombination of the cell fractions. Each preparation was tested in three vehicles: saline, alum (0.5%), and Freund Incomplete Adjuvant (50%). The turkeys vaccinated with these preparations were challenged by exposure to an experimental epornitic of fowl cholera. The combination fraction appeared to be the most promising vaccine when compared to the protective action of the commercial bacterin included in the test as a positive control.
Fowl Cholera Immunization in Turkeys
Authors: Dawe Donald L. , Davis Richard B. , Brown John , Foster John W. , Srivastava K. K.
Published: December 2020

Groups of turkeys were challenged with
Pasteurella multocida
(P-1059) by the contact method. In this method, turkeys are artificially infected by the intramuscular injection of
P. multocida
organisms and are then introduced into the test group. The death patterns resulting from this contact method of challenge are either normally distributed or skewed to the right.
Accuracy of Smallpox Diagnosis by Immunfluorescence with a Purified Conjugate
Authors: Noble John , Loggins Mary S.
Published: December 2020

A direct fluorescent-antibody test for smallpox is described which utilizes a conjugated antivaccinia serum that was purified by diethylaminoethyl fractionation. The purity of the conjugate was analyzed by density gradient centrifugation, and specific staining of smallpox and nonsmallpox specimens was measured quantitatively by a photovoltmeter. Variola elementary bodies were identified in all of the specimens of vesicular and pustular fluid collected from 50 smallpox patients, and no false-positive diagnoses were made on specimens from 27 patients with varicella or other nonpox viral exanthems. However, 63.8% of the specimens of vesicular and pustular fluid smeared on slides in the field were unusable because of bright nonspecific fluorescence. For this reason, the fluorescent-antibody test does not compare favorably with other routine laboratory tests for smallpox.
Prevention of Oxidation of Transport Media
Authors: Smith John P.
Published: December 2020

A means of preventing transport media from undergoing oxidation by sealing tubes with paraffin is described.
Fungal Disfigurement of Paper, and Soft Rot of Cedar Shingles
Authors: Eveleigh D. E.
Published: December 2020

Disfiguration of paper by
Cladosporium cladosporioides
is described, and the association between “soft rot” fungi and the greying of cedar shingles in marine locations is reported.

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Nuclear Distribution in the Mycelium of
Claviceps
and the Problem of Strain Selection
Authors: Hareven D. , Koltin Y.
Published: December 2020

Cytological studies of the developing mycelium of
Claviceps
suggest that genetic uniformity may be obtained in strains derived from single spores.
Improved Automatic Inoculator for Bacterial Cultures
Authors: Maier S.
Published: December 2020

A simple automatic inoculator which allows the simultaneous inoculation of several cultures with identical or different inocula is described. The use of Teflon spaghetti tubing allows great flexibility in handling and placing of components. The inoculator can be adapted to handle aerobic and anaerobic bacteria.
Concentrated Cultures of
Leuconostoc citrovorum
Authors: Gilliland S. E. , Anna E. D. , Speck M. L.
Published: December 2020

Two single-strain cultures of
Leuconostoc citrovorum
were grown in a broth medium with automatic
p
H control. Culture concentrates were prepared by centrifugally harvesting the cells and resuspending them in 1/50th the original volume in 10% nonfat milk solids. The concentrates were stored in liquid nitrogen until analyzed. The maximum population attainable was approximately equal when cultures were grown at
p
H 6.0, 6.5, or 7.0 with sodium hydroxide or ammonium hydroxide as the neutralizer. Citrate was required in the growth medium for the cultures to be able to produce diacetyl subsequently in milk. At
p
H 6.0, the cells reached maximum population and ability to produce diacetyl. Organoleptic analysis by an experienced flavor panel showed a preference for cottage cheese creamed with a creaming mixture prepared with a culture concentrate rather than a normal culture. The culture concentrates maintained their viability and ability to produce diacetyl for at least 30 days when stored in liquid nitrogen.
Automated Fluorescent Treponemal Antibody Test: Instrument and Evaluation
Authors: Lewis Joel S. , Duncan William P. , Stout Genevieve W.
Published: December 2020

Two evaluations of the automated fluorescent treponemal antibody (AFTA) test for the serodiagnosis of syphilis are described. The results of AFTA and manually performed fluorescent treponemal antibody-absorption (FTA-ABS) tests were compared on serum samples from clinically defined donor groups, and the reproducibility of each procedure was studied. Significant improvement of AFTA test results was obtained in the most recent study after developmental modifications of the instrument and test technique. AFTA test agreement with both syphilis and nonsyphilis categories was considered good. With the increasing usage of the FTA-ABS test as an effective tool for the diagnosis of syphilis, successful automation of this procedure is particularly timely and significant.
Survival and Activity of Frozen Starter Cultures for Cheese Manufacture
Authors: Keogh Barbara P.
Published: December 2020

A study has been conducted on the effect of freezing and storage in liquid nitrogen on 13 strains of lactic streptococci. Cultures were frozen in droplet form and collected in mesh bags. After rapid thawing, the activity of the frozen cultures was compared with a culture of the same organism of the age usually used in cheese-making. The activities of the test and control cultures were traced simultaneously by continuous recording of the
p
H changes in inoculated milks. Viable counts were performed before and after freezing in liquid nitrogen and after storage in liquid nitrogen. There was no decrease in viable count or loss in activity of the cultures due to freezing and storage. Frozen cultures of some strains showed a shorter lag period after inoculation of milk than control cultures. Frozen concentrated cheese-starter cultures behaved normally in the manufacture of Cheddar cheese.
Amphotericin B Serum Concentrations During Therapy
Authors: Fields Branch T. , Bates Joseph H. , Abernathy Robert S.
Published: December 2020

Therapeutic outcome of patients being treated for systemic mycoses with amphotericin B is possibly related to the serum concentrations of this drug that are produced in these patients. Because current data are conflicting, the magnitude of these concentrations was restudied by using a bioassay which gave precise and accurate results. The highest of 155 serum concentrations was 2.01 μg/ml. Mean concentrations were 1.21, 0.62, and 0.32 μg/ml, at 1, 18, and 42 hr, respectively, after intravenous infusion of amphotericin B. This drug was detected in serum 7 weeks after completion of treatment, but it could not be detected 13 weeks after treatment. Drug levels did not appreciably decrease in serum stored for 8 to 9 months at − 10 C. Unequal serum content in assay tubes and measurement of assay turbidity by visual inspection may explain previously reported amphotericin B levels of 3.0 to 12.5 μg/ml.
Influence of Water Activity on the Growth of
Clostridium perfringens
Authors: Strong Dorothy H. , Foster Edith F. , Duncan Charles L.
Published: December 2020

Each of four strains of
Clostridium perfringens
was grown in modified fluid thioglycolate medium which was adjusted to yield selected water activity (a
w
) levels. The adjustments to secure the desired a
w
levels were made with NaCl, KCl, or glucose. At each a
w
level, further modification was effected to produce four
p
H values. Cultures were incubated at either 37 or 46 C. The solute used to achieve the reduced a
w
levels appeared to have a definite effect on the magnitude of growth achieved, the rate of growth, and the limiting a
w
at which growth would occur. Use of glucose as the controlling solute permitted growth at the lowest a
w
level tested, 0.960, and yielded the greatest magnitude of growth as measured by turbidity values, at all of the a
w
levels investigated. Cultures grown in the medium with added KCl generally demonstrated the longest lag times and the least amount of growth. Regardless of specific solute used, as the a
w
level was lowered and the
p
H value decreased within each a
w
level, the rate and amount of growth were lessened. It appeared, however, that low
p
H values had less effect on inhibiting growth at low a
w
levels than at higher a
w
levels. Those cultures incubated at 46 C generally exhibited shorter lag periods than those at 37 C, although the maximal growth attained was somewhat less than that achieved at 37 C. The response to all of the investigated conditions was similar for each of the four strains tested.
Vibrios from Fish Pen Slime Which Mimic
Escherichia coli
on Violet Red Bile Agar
Authors: Rosen A. , Levin R. E.
Published: December 2020

Organisms from fish pen slime which mimicked coliforms and
Escherichia coli
on Violet Red Bile Agar were identified as members of the genus
Vibrio
on the basis of metabolic and morphological characteristics.
Optimum Skin Blending Method for Quantifying Poultry Carcass Bacteria
Authors: Avens John S. , Miller Byron F.
Published: December 2020

Optimum blending fluids and blending times for use in quantifying bacteria on poultry carcass skin by the skin “blending” method were determined. Butterfield's buffered-phosphate diluent, physiological saline solution (0.85% NaCl), peptone water (0.1% peptone), and deionized water, each at four different skin blending times of 1, 2, 3, and 4 min, were compared. The comparison was based on relative numbers of bacteria per cm
2
of skin, enumerated by each combination on turkey carcasses. Peptone water and physiological saline solution each yielded significantly (
P
< 0.01) higher bacteria counts from turkey carcass skin samples than did Butterfield's buffered-phosphate diluent or deionized water. There were no significant differences among the four skin blending times and no significant interaction effect between the two factors tested.
Endocarpic Microorganisms of Two Types of Windrow-Dried Peanut Fruit (
Arachis hypogaea
L.)
Authors: Porter D. Morris , Garren Kenneth H.
Published: December 2020

The endocarpic microorganisms of peanut fruit dried in either a random windrow (plants left as they fell from the digger) or an inverted windrow (plants inverted to expose fruit to sunlight) were different from that of freshly dug fruit.
Chaetomium, Penicillium, Trichoderma, Rhizoctonia
, and
Fusarium
were the dominant fungi found associated with shells (pericarp) of freshly dug fruit. The dominant fungi of shells of windrowed fruit included
Chaetomium, Rhizoctonia, Fusarium, Sclerotium
, and
Alternaria.
Seeds of freshly dug fruit were dominated by
Penicillium
and
Aspergillus.
The only dominant species in seed of windrowed fruit was
Penicillium.
Microorganisms were isolated from shells and seed of freshly dug fruit at a frequency of 79% and 52%, respectively. The percentage of infestation was reduced by drying in the field. This was particularly true of the inverted windrow. The proportion of shells and seed infested with a microorganism was reduced 13% and 36%, respectively, after field drying for 5 to 7 days in random and inverted windrows. Microorganisms were isolated much more frequently from shell pieces (73%) than from seed (36%).
Purification and Properties of a Glycerol Ester Hydrolase (Lipase) from
Propionibacterium shermanii
Authors: Oterholm Anders , Ordal Z. John , Witter Lloyd D.
Published: December 2020

An intracellular glycerol ester hydrolase (lipase) from
Propionibacterium shermanii
was recovered from cell-free extracts and purified by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography on diethylaminoethylcellulose. Maximum enzyme activity was observed at
p
H 7.2 and 47 C when an emulsion of tributyrin was used as substrate. The enzyme was stable between
p
H 5.5 and 8. Heating the enzyme solution at 45 C for 10 min resulted in a 75% decrease in activity. Maximum rate of hydrolysis of triglycerides was observed on tripropionin, followed in order by tributyrin, tricaproin, and tricaprylin. The lipase was strongly inhibited by mercury and arsenicals, but specific sulfhydryl reagents had little or no inhibiting effect on the enzyme activity. The enzyme also showed some esterase activity, but the hydrolysis of substrates in solution was small as compared to the hydrolysis of substrates in emulsion.
Viability and Infectivity of Measles Virus-Infected Nervous Tissue Frozen in Cryoprotective Medium
Authors: Albrecht Paul , Schumacher Heinz P.
Published: December 2020

Measles virus-infected hamster brain tissue remained viable when frozen slowly in medium containing dimethyl sulfoxide. This procedure was essential for isolation of neurotropic measles virus from tissue specimens stored frozen.
Preservation of
Mycoplasma
Strains by Freezing in Liquid Nitrogen and by Lyophilization with Sucrose
Authors: Norman Margaret C. , Franck Eva B. , Choate Richard V.
Published: December 2020

Procedures for maintaining
Mycoplasma
strains are described. Liquid nitrogen storage provided an adequate means for keeping stock cultures stable. Over 74 strains of approximately 26 species have been preserved in this way, some for as long as 9 years.
Mycoplasma
strains can also be recovered satisfactorily from the freeze-dried state when the procedure described includes the use of 12% (v/v) sucrose as an additive. Fifteen strains representing 12 or more species were subjected to a freeze-drying program with and without sucrose added to concentrated cell suspensions in growth medium. Cell counts indicate improved survival with sucrose.
Simplified Procedure for Preparation of Specific Antibodies to Gamma Globulins
Authors: Olsen Richard G. , McCammon James R. , Yohn David S.
Published: December 2020

Antibodies were prepared to rhesus monkey, rabbit, dog, and hamster gamma globulins which had been purified by agar-block electrophoresis. Immunoelectrophoretic analysis demonstrated that these antisera were specific for gamma globulin components in whole serum. The use of these antisera as secondary serological reagents was examined.
Characterization of Clostridia by Gas Chromatography: Differentiation of Species by Trimethylsilyl Derivatives of Whole-Cell Hydrolysates
Authors: Farshy David C. , Moss C. Wayne
Published: December 2020

Trimethylsilyl (TMS) derivatives prepared from whole-cell hydrolysates of 36 strains, representing 10 species of
Clostridium
were examined by gas-liquid chromatography (GLC). The TMS profile of each species contained a group of peaks which characterized the species. Variation among strains within a species was much lower than variation between species. Some of the closely related clostridia could be differentiated by comparing their TMS profiles. Strains of
Clostridium botulinum
were distinguished from
C. sporogenes
on the basis of the ratio of two GLC peaks which corresponded to arabinose and glucose. A peak with a retention time identical to that of mannose was present in all
C. bifermentans
strains but was absent in those of
C. sordellii
.
Fecal Streptococci on Barley and Malt Kernels and Instant Malted Milk Powder
Authors: Stark Egon
Published: December 2020

Among 500 barley kernels, tested singly, 1.8% (9 kernels) were positive for fecal streptococci. Among 800 malt kernels, tested singly by the same procedure, 68% (540 kernels) were positive for fecal streptococci. In unsulfured and sulfured malts, 67 and 68% of the kernels, respectively, were positive for these bacteria. Fecal streptococci were also isolated by an enrichment procedure from two brands of instant malted milk powder sold in supermarkets. Seventy randomly picked isolates from malts were identified to be fecal streptococci, belonging probably to more than one species.
Product Inhibition of the Fermentative Formation of Glutamic Acid
Authors: Nunheimer T. D. , Birnbaum J. , Ihnen E. D. , Demain A. L.
Published: December 2020

The addition of penicillin to cells of
Corynebacterium glutamicum
growing in 5-liter fermentors initiated the excretion of glutamic acid. The rate of glutamate production in fermentors declined continuously with time and reached 75% of the initial rate in 24 hr after penicillin had been added. The addition of glutamate to resting cell suspensions had only a slight effect on sugar utilization but caused a marked decrease in glutamate excretion. It is suggested that the high level of glutamate accumulating in the fermentation broth is responsible for inhibiting its own production.
Semiquantitative Oropharyngeal Culture Technique
Authors: Johnston Dianne A. , Bodey Gerald P.
Published: December 2020

A semiquantitative method for determining the concentration of organisms constituting the normal oropharyngeal flora has been developed. Eleven species of organisms were isolated from the 18 subjects studied. The concentration of organisms in multiple samples, taken at 5-min intervals, was quite similar. The concentration of organisms increased slightly at the end of the day. Obtaining specimens on different days of the week did not appreciably affect the concentration or kinds of organisms. Eating had only a minimal effect on the oropharyngeal flora, but brushing teeth reduced the concentration of organisms substantially. When specimens were obtained 6 months after the initial specimens, the concentration of organisms remained the same but the species of organisms isolated varied considerably. The gargle method was compared to a swab method and proved to be superior. This method of obtaining oropharyngeal culture specimens is reliable and useful as a means of monitoring the normal oropharyngeal flora.
Effects of a Systemic Antibiotic on Nasal Bacterial Ecology in Man
Authors: Aly Raza , Maibach Howard I. , Strauss Walter G. , Shinefield Henry R.
Published: December 2020

The nasal flora of coagulase-positive staphylococcus carriers and noncarriers was studied in aerobic conditions in 17 individuals. Five hundred milligrams of cephalexin was given orally four times daily for 12 days, and its effects on the nasal bacteria were determined quantitatively before, during, and after treatment. The total count obtained before the drug treatment was 5.4 × 10
6
in carriers and 3.9 × 10
6
in noncarriers. The lowest total count observed was 3 days after the cessation of the drug. The increase in gram-negative rods was seen 9 days after antibiotic therapy, not during the greatest reduction of gram-positive bacteria. Coagulase-positive cocci and diphtheroids were most sensitive to drug treatment. After 36 days, the total count was restored to pretreatment level. Diphtheroids did not return to the original number and were replaced by a corresponding increase of resistant coagulase-negative cocci. An inverse relationship between coagulase-negative cocci and lipophilic diphtheroids was seen in the anterior nares of many individuals. No gross difference in nasal ecology to differentiate carriers from noncarriers was seen.
Direct Assessment of Viral Aerosols on Cell Cultures
Authors: Hankins William A. , Hearn Henry J.
Published: December 2020

A technique is described for the direct exposure of cell cultures to airborne virus enabling quantitation of the virus in concentrations as low as one plaque-forming unit per liter of air.
Comparison of Agar and Agarose Preparations for Mengovirus Plaque Formation
Authors: Borden Ernest C. , Gary G. William , Murphy Frederick A.
Published: December 2020

An agarose overlay yielded mengovirus plaques earlier and in greater size and number than overlays of chemically undefined agars with or without enhancers. Marked variability in plaque-forming efficacy of commercial agarose preparations was noted.
Preparation of Noninfectious Arbovirus Antigens
Authors: Brand Orville M. , Allen William P.
Published: December 2020

Noninfectious arbovirus antigens were prepared from borate-saline suspensions of infected suckling mouse brain buffered with tris(hydroxmethyl)aminomethane and treated with β-propiolactone (BPL). The activity and stability of these antigens were enhanced by altering the buffering system, by passing the virus seed through a series of four or more continuous passages in the brains of suckling mice, or by a combination of these procedures. The titers of group A and B arbovirus antigens were comparable to titers of antigens extracted by the conventional sucroseacetone-BPL (SA-BPL) method. Antigens prepared from some ungrouped and Bunyamwera arboviruses by either the borate-saline-BPL or SA-BPL method produced inconsistent results and will require the development of more unique procedures to obtain suitable hemagglutinating antigens.
Degradation and Utilization of Hemicellulose from Intact Forages by Pure Cultures of Rumen Bacteria
Authors: Coen Judith A. , Dehority B. A.
Published: December 2020

Several pure strains of rumen bacteria have previously been shown to degrade isolated hemicelluloses from a form insoluble in 80% acidified ethanol to a soluble form, regardless of the eventual ability of the organism to utilize the end products as energy sources. This study was undertaken to determine whether similar hemicellulose degradation or utilization, or both, occurs from intact forages. Fermentations by pure cultures were run to completion by using three maturity stages of alfalfa and two maturity stages of bromegrass as individual substrates. Organisms capable of utilizing xylan or isolated hemicelluloses could degrade and utilize intact forage hemicellulose, with the exception of two strains of
Bacteroides ruminicola
which were unable to degrade or utilize hemicellulose from grass hays. Intact forage hemicelluloses were extensively degraded by three cellulolytic strains that were unable to use the end products; in general, these strains degraded a considerably greater amount of hemicelluloses than the hemicellulolytic organisms. Hemicellulose degradation or utilization, or both, varied markedly with the different species and strains of bacteria, as well as with the type and maturity stage of the forage. Definite synergism was observed when a degrading nonutilizer was combined with either one of two hemicellulolytic strains on the bromegrass substrates. One hemicellulolytic strain, which could not degrade or utilize any of the intact bromegrass hemicellulose alone, almost completely utilized the end products solubilized by the nonutilizer. Similar synergism, although of lesser magnitude, was observed when alfalfa was used as a substrate.
Purification, Concentration, and Inactivation of Venezuelan Equine Encephalitis Virus
Authors: Gruber Jack
Published: December 2020

Venezuelan equine encephalitis (VEE) virus was purified and concentrated by chromatography of tissue culture supernatant fluids on diethylaminoethyl-cellulose columns. Stepwise gradient elution studies indicated a broad elution pattern for the virus, with recovery occurring from 0.05 to 0.7
m
NaCl. Optical density, infectivity, hemagglutination (HA), and complement fixation (CF) assays indicated that complete recovery of input virus in highly purified form was possible. Single-step elution with 0.7
m
tris(hydroxymethyl)aminomethane-succinate-salt buffer resulted in a virus volume decrease of 85% with a concomitant increase in infectivity and antigenicity. Recoveries consistently equaled or exceeded 100% of the input preparations. Additional purification of column-recovered virus was obtained by sedimentation of pooled virus eluates on 50% sucrose cushions. Exposure of borate saline and 0.5% histidine suspensions of purified VEE virus preparations to 6 � 10
6
r of gamma radiation resulted in a loss of infectivity for tissue culture and a loss of lethality for weanling and suckling mice. Inactivation was an exponential function of the dosage. In contrast to infectivity, antigencity (HA and CF) of both saline and histidine preparations was retained after irradiation with doses as high as 6 � 10
6
r. Purified and irradiated VEE virus preparations have been successfully used for routine serological tests and are being evaluated as vaccines.
Biological Assays for Two Mycotoxins Produced by
Fusarium tricinctum
Authors: Burmeister H. R. , Hesseltine C. W.
Published: December 2020

A survey was made to detect microorganisms useful for assaying butenolide [4-acetamido-4-hydroxy-2-butenoic acid γ-lactone] and T-2 toxin [4β, 15-diacetoxy-8α-(3-methylbutyryloxy)-12,13-epoxytricothec -9-en-3α-ol]. These mycotoxins produced by strains of
Fusarium tricinctum
have been implicated in mycotoxicosis of livestock. Although butenolide proved to be a very weak antibiotic, assay discs containing 100 μg of this toxin inhibited
Sprillum serpens
NRRL B-2052,
Vibrio tyrogenus
NRRL B-1033, and
Xanthomonas campestris
NRRL B-1459. T-2 toxin had no effect on 54 bacterial strains but inhibited 6 of 11 fungi. Growth of
Rhodotorula rubra
NRRL Y-7222 and
Penicillium digitatum
NRRL 1202 was retarded by assay discs containing 4 μg of T-2 toxin. Solutions with less than 1 μg of T-2 per ml toxin were readily detected by a pea seed germination test. Germination was reduced more than 50% when seeds imbibed solutions of 0.5 μg of T-2 toxin per ml. Butenolide had no effect on pea seed germination at concentrations as high as 200 μg/ml.
Resistance of
Bacillus subtilis
Spores to Inactivation by Gamma Irradiation and Heating in the Presence of a Bactericide
Authors: Deasy P. B. , K�ster E. , Timoney R. F.
Published: December 2020

Aqueous suspensions of
Bacillus subtilis
NCTC 8236 spores, surviving 150,000 or 300,000 rad of gamma irradiation under air from a cesium-137 source, exhibited an enhanced rate of inactivation, compared to nonirradiated spores, when heated with different phenolic bactericides. The apparent magnitude of the enhanced inactivation rate, observed from survival curves, increased progressively with the irradiation dose applied and diminished progressively as the severity of heat treatment with 0.2% chlorocresol was increased either by raising the temperature from 70 to 90 C or reducing the
p
H from 8 to 6. The enhanced inactivation rate was unaffected when the concentration of sodium chloride added to 0.2% chlorocresol was altered from 0.4 to 0.8%. The enhancement effect was also observed when the heat treatment was carried out with 0.5% phenol and 0.3%
m
-cresol.
Factors Affecting the Secretion of Staphylococcal Enterotoxin A
Authors: Markus Z. H. , Silverman G. J.
Published: December 2020

The biosynthesis of enterotoxin A by replicating and nonreplicating cells was investigated. Unlike enterotoxin B, a secondary metabolite, enterotoxin A secretion resembled that of a primary metabolite by being secreted during the exponential phase of growth. The amount of toxin produced per unit of growth was not influenced by NaCl, NaNO
2
, or NaNO
3
. Several surfactants increased toxin secretion. Toxin secretion by nonreplicating cells was inhibited by chloramphenicol and 2, 4-dinitrophenol but not by streptomycin or penicillin G. The optimal
p
H for enterotoxin A production was 6.5 to 7.0. The findings suggest a number of possible reasons for the higher incidence of food poisonings caused by enterotoxin A as compared to enterotoxin B.
Differential Light Scattering Measurements of Heat-Treated Bacteria
Authors: Berkman Richard M. , Wyatt Philip J.
Published: December 2020

Effects of heat on diameter, size distribution, and refractive index of
Staphylococcus epidermidis
suspensions were determined accurately by computer analysis of differential light scattering data.
Enhanced Immunogenicity in Mice of a Purified, Tween-Ether-Treated Influenza Vaccine
Authors: Fenters James D. , Yamashiroya Herbert M. , Petzold Robert F. , Tolkacz Vivian K.
Published: December 2020

The immunogenic response of mice vaccinated intranasally or subcutaneously with increasing doses of a purified, concentrated intact A
2
/Taiwan influenza vaccine or its Tween-ether derived vaccines was compared. Immunogenicity was measured by serum neutralization and hemagglutination-inhibition antibodies, lung lesions scores, and protection against respiratory challenge with live airborne influenza virus. Intact (untreated) vaccine, Tween-ether-treated (ET) vaccine, and the isolated hemagglutinins (HA) provided protection and stimulated homologous antibody response at the 35- and 70-chicken cell agglutination (CCA) unit level. At a lower dosage level, the vaccines administered by the subcutaneous route appeared to confer better protection. The ET vaccine was superior to intact virus or HA vaccines when administered subcutaneously. The minimum amount of the HA and intact vaccine given subcutaneously that protected mice against respiratory challenge was 7 CCA units (3.5 units injected twice) compared to 0.7 CCA units (0.35 units injected twice) for the ET vaccine. No heterologous antibody to the A/PR/8/34 or B/Mass/3/66 was noted. Low-level serum-neutralizing antibody was found against the A
2
/Japan/170 strain but, despite high levels of homologous A
2
/Taiwan/64 antibody, no cross-reactivity was found with the recent A
2
/Hong Kong/68 variant.
Ester Production by
Pseudomonas fragi
IV. Demonstration of Esterase Activity
Authors: Reddy M. C. , Lindsay R. C. , Montgomery M. W.
Published: December 2020

Assay of the esterase activity of sonically treated cell-free extracts, whole cell suspensions, and supernatant fluid of
Pseudomonas fragi
cultures with a differential respirometer revealed that the esterases were intracellular. Polyacrylamide-gel electrophoresis demonstrated six bands of esterase activity, which revealed substrate specificity differences. Band 1 exhibited slow mobility, bands 2, 3, and 4 moderate mobility, and bands 5 and 6 rapid mobility. Six bands were active with α-naphthyl acetate, four bands with α-naphthyl propionate, and 5 bands with αnaphthyl butyrate. These esterases appeared to be more active with aromatic esters than with aliphatic esters.
Role of Microbial Iron Transport Compounds in the Bacterial Spoilage of Eggs
Authors: Garibaldi J. A.
Published: December 2020

Microbial iron transport compounds, belonging either to the hydroxamate family excreted by pseudomonads, or to the phenolate family excreted by salmonellae, reverse the bacteriostatic effect of conalbumin on the growth of these bacteria in egg white. The presence of microgram quantities of these compounds permits both salmonellae and pseudomonads to reach dense populations in egg white. The role of these iron transport compounds in bacterial egg spoilage is discussed.