bluuebunny/crossref_metadata_2025 huggingface dataset:
Antiviral Activity of a bis-Benzimidazole Against Experimental Rhinovirus Infections in Chimpanzees
Authors: Shipkowitz N. L. , Bower R. R. , Schleicher J. B. , Aquino F. , Appell R. N. , Roderick W. R.
Published: December 2020

The marked antiviral activity of (
S,S
-1,2-bis(5-methoxy-2-benzimidazolyl)-1,2-ethanediol (Abbott 36683) against rhinoviruses in tissue culture warranted investigation of its antiviral activity in vivo. Antiviral levels in mouse sera were attained with an oral dose as small as 10 mg/kg and detectable antiviral levels of drug were also found in lung, liver, kidney, intestinal contents, and urine of mice given a single 300 mg/kg oral dose. Antiviral serum levels were also obtained when monkeys were given a single oral dose of Abbott 36683. Six chimpanzees were infected with 100 median tissue culture infective dose units (TCID
50
) of rhinovirus 30. Three of the animals were treated with Abbott 36683, 100 mg/kg daily for 4 consecutive days. Virus shedding occurred in the infected controls but could not be demonstrated in the treated animals from postinfection days 1 to 8. Two of the treated animals did, however, shed virus on day 9. The compound was retested in chimpanzees at dosage levels of 15 and 50 mg/kg daily for 4 days. Each animal was challenged with 100 TCID
50
of rhinovirus 49. Partial protection was obtained. In a third trial, a single 100 mg/kg dose of the compound was administered to chimpanzees infected with rhinovirus 44. Virus was isolated from all throat smears taken from treated animals, indicating that at the lowest drug level no protection occurred.
Simple Method for Inducing Ascospore Formation in Yeasts
Authors: Lonsane B. K. , Singh H. D. , Baruah J. N. , Iyengar M. S.
Published: December 2020

A new method for inducing ascospore formation in yeasts is described and compared with conventional methods for its performance. The method has the advantage of simplicity, reproducibility, and saving of time.
Inoculation Technique for Fungus Cultures
Authors: Fusaro Ramon M.
Published: December 2020

A plastic straw and wood applicator stick serve as a simple, inexpensive, and disposable inoculation unit for fungal studies. The method gives a uniform and intact inoculum. The technique is especially useful because a large number of agar plates can be inoculated rapidly.
Adaptation of Swinepox Virus to an Established Cell Line
Authors: Garg S. K. , Meyer R. C.
Published: December 2020

Swinepox virus was successfully adapted to the PK-15 cell line, but not the MDBK cell line. Virus titers obtained in the PK-15 host cell system were comparable to diploid swine kidney cell cultures.
Interval Scanning Photomicrography of Microbial Cell Populations
Authors: Casida L. E.
Published: December 2020

A procedure is presented for photographically recording growth and other changes occurring within microbial populations over a period of time.
Use of Dogs as an Assay for
Clostridium perfringens
Enterotoxin
Authors: Bartlett M. L. , Walker Homer W. , Ziprin Richard
Published: December 2020

Three techniques for using the dog as an assay organism for
Clostridium perfringens
enterotoxin are described. These are believed to be more convenient than ligated ileal-loop procedures.
Numerical Taxonomy of Coryneform Bacteria Isolated from Pond-Reared Shrimp (
Penaeus aztecus
) and Pond Water
Authors: Vanderzant C. , Judkins P. W. , Nickelson R. , Fitzhugh H. A.
Published: December 2020

Gram-positive, catalase-positive, nonsporeforming, pleomorphic rods isolated from pond-reared shrimp and pond water were compared with type cultures of the
Corynebacteriaceae
. Classification of the type cultures based on 66 cell and colony characters proved comparable to one based on 163 morphological, biochemical, and physiological characters. This similarity was not observed with pond isolates. With the aid of numerical analysis, pond isolates could be placed into six major groups based on certain biochemical and physiological tests. Coryneform bacteria isolated from shrimp and water exhibited little similarity to the type cultures. The pond isolates probably are members of the
Corynebacteriaceae
not previously studied in detail.
Twenty-Four-Hour Immunofluorescence Technique for the Detection of Salmonellae in Nonfat Dry Milk
Authors: Reamer R. H. , Hargrove R. E.
Published: December 2020

A detection procedure was developed in which a newly devised lysine-iron medium was used as a one-step selective and enrichment medium for detection of salmonellae by the fluorescent-antibody technique. Incubation was conducted in two steps: initially at 30 C for 5 hr to resuscitate sublethally stressed cells, followed by incubation at 39 C for 17 hr. Twenty-seven strains of salmonellae from groups A-I were utilized in the development of this procedure which was sensitive enough to detect one
Salmonella
bacterium in 100 g of nonfat dry milk.
Effect of Monosodium
n
-Alkylsalicylates on Spores of
Bacillus subtilis
Authors: Buckley D. , Thomas J.
Published: December 2020

The effects of several monosodium
n
-alkylsalicylates on washed spores of
Bacillus subtilis
have been examined. None of the compounds was sporicidal, but in general they prevented dormancy induced by incubating the spores in water. This effect was related to the position in the ring and size of the alkyl groups substituted on the salicylic acid nucleus.
Passive Hemagglutination-Inhibition Test for Typing Foot-and-Mouth Disease Virus
Authors: Warrington R. E. , Kawakami Y.
Published: December 2020

In addition to currently used serological tests for the occurrence of foot-and-mouth disease virus (FMDV), a specific “passive” hemagglutination-inhibition (HAI) test has been developed as a supplement. Serial twofold dilutions of antiserum (0.05 ml) were mixed with 0.05 ml of a constant concentration of FMDV. After incubating for 30 min at 37 C, agglutinating antibodies were determined by adding 0.1 ml of 2.5% virus-sensitized erythrocytes. The minimum concentration of antiserum required to agglutinate the erythrocytes defined the inhibition in the HAI test. Similar tests using different concentrations of virus to inhibit antibodies were carried out in parallel fashion. The relationship between the logarithm of the HAI titer and the concentration of inhibiting virus was nearly first order (
P
> 0.25). The slope was used as a measure of the relative specificities of the antigen-antibody interaction and was independent of concentration. The HAI test was type-, subtype-, strain-, and variant-specific with the viral antigens used. In particular, typing was performed directly on bovine antisera.
Comparison of the Immunofluorescent-Cell Counting and Plaque Methods for the Assay of Vaccinia Virus
Authors: Ibrahim Abdul L. , Loh Philip C.
Published: December 2020

The immunofluorescent-cell counting method was compared with the agarand liquid-overlay plaque techniques for the assay of vaccinia virus. In addition to being as quantitative, reproducible, and simple to use as the two plaque techniques, the immunofluorescent assay method was found to be more sensitive, rapid, and specific.
Epidemiological Differentiation of
Serratia marcescens:
Typing by Bacteriocin Production
Authors: Farmer J. J.
Published: December 2020

A new method for comparing and differentiating strains of
S. marcescens
is described which has proved useful in determining the epidemiology of hospital infections. Strains were grown in Trypticase soy broth, and bacteriocin production was induced with mitomycin C for 5 hr. The bacteriocin lysates were then spotted onto nine standard indicator strains, which were chosen with the aid of computer analysis from the 118 indicators tested. After 24 hr at 37 C, zones of inhibition due to bacteriocins were recorded. One hundred twentynine strains were differentiated into 72 different bacteriocin production patterns, but 11 strains were nontypable. None of the 45 other strains of
Enterobacteriaceae
produced bacteriocins. Bacteriocin production was a stable epidemiological marker. Colonial mutants always had identical patterns, as did the same strain which has passed from patient to patient through cross-infection. The new technique does not require any specialized equipment and can be used in laboratories with limited budgets. The applications of the new method in cross-infection studies and as a supplement to serological typing are discussed.
Effect of Oxidized Spermine and Other Aldehydes on the Infectivity of Vaccinia Virus
Authors: Bachrach U. , Rosenkovitch E.
Published: December 2020

The antiviral activity of oxidized spermine was compared with that of other aldehydes. Suspensions of vaccinia virus were incubated at 37 C with various concentrations of the aldehydes, and the infectivity of the viruses was determined by the plaque assay. Oxidized spermine at a concentration of 0.82 mM completely inactivated a suspension of vaccinia virus (1.4 × 10
8
plaque-forming units) after incubation at 37 C for 10 hr. Glutaraldehyde and formaldehyde were less active when compared on a molar basis, but acrolein resembled oxidized spermine in its antiviral activity. Because acrolein is produced from oxidized spermine at only 20 to 30% yield, it is unlikely that the biological activity of the latter is due to acrolein formed during the spontaneous degradation of oxidized spermine.
Factors Influencing the Production of H and M Antigens by
Histoplasma capsulatum
: Development and Evaluation of a Shake Culture Procedure
Authors: Ehrhard Hugh-Bert , Pine Leo
Published: December 2020

Studies were undertaken to improve the production of histoplasmin for use in complement-fixation tests and in the determination of H and M antibodies. A shake culture method performed at 25 C was developed with a yeast-phase inoculum. Eight strains of
Histoplasma
were tested in three synthetic media to evaluate the effects of strain and medium on H and M antigen production. Intrastrain variation was negligible, and antigen production was reproducible. All of the strains produced H antigen; six strains produced both H and M antigens, and two produced only H antigen. The time of H and M antigen appearance varied with the medium; M antigen appearance was dependent upon the strain and medium used. Titers of M antigen appeared to be greater in stagnant culture.
Factors Influencing the Production of H and M Antigens by
Histoplasma capsulatum
: Effect of Physical Factors and Composition of Medium
Authors: Ehrhard Hugh-Bert , Pine Leo
Published: December 2020

Stagnant culture methods have permitted only limited physiological studies of the production of H and M antigens by
Histoplasma capsulatum
because, with such methods, antigen production is uncontrolled. In this investigation, a shake culture method was used to convert yeast-phase inoculum to mycelialphase growth at 25 C. Results strongly suggest that the release of H and M antigens relates to autolysis of the cells. Among the factors influencing production of H and M antigens under shaking conditions, choice of strain was the most important. Alterations of carbon or nitrogen source or variations in amino acid to carbohydrate ratios had limited influence on antigen production. With a strain that produced both H and M antigens, however, proportions of titers of M to H antigens could be made to vary considerably by changes in the medium, the
p
H, and the temperature. Results suggest that the source of M antigen during autolysis is enzymatic dissolution of the cell wall. The source of H antigen is more obscure. Production of both antigens may be differentially controlled under conditions of good reproducibility by a correct choice of strain and manipulation of culture medium.
Structures Suggesting Cell-Wall-Deficient Forms Detected in Circulating Erythrocytes by Fluorochrome Staining
Authors: Pohlod Donald J. , Mattman Lida H. , Tunstall Lucille
Published: December 2020

Cell-wall-deficient (CWD) forms of bacteria are associated with certain cases of idiopathic septicemia. In this preliminary study of blood examined immediately after venipuncture, structures with a morphology characteristic of CWD forms were seen parasitizing the erythrocytes. These inclusions were usually circumferential, but in some cases they protruded from the red cells. The CWD forms were detected by staining with Gould's rhodamine-labeled muramidase, which reacted similarly to acridine orange but with greater specificity. A blocking test, employing unlabeled muramidase, indicated the specificity of the reaction between muramidase and the microbial substrate. Reaction of the forms with muramidase indicates their bacterial, rather than mycoplasmal, nature. Thus in vivo CWD forms have a detectable component of muramic acid, at least in certain cases. Sixty-eight individuals with a diagnosis of fever of unknown origin were tested, with 51 nondebilitated individuals serving as controls. More intraerythrocytic forms reacting with muramidase were found in the patients than in the controls. Nearly 40% of the cases had a relatively high incidence of erythrocyte parasitism. In some instances when freshly drawn blood was examined, the structures, which appear to be microbial, extended in rhizoid filaments from the erythrocytes.
Stabilizing Effect of Magnesium Sulfate on Avian Infectious Bronchitis Virus Propagated in Chicken Embryo Kidney Cells
Authors: Coria Manuel F.
Published: December 2020

The Beaudette strain of avian infectious bronchitis virus propagated in chicken embryo kidney cells is stabilized by exposure to 1 M MgSO
4
at 50 C for 80 min, at
p
H values ranging from 4 to 10.
Hemagglutination Inhibition for Serogrouping of
Neisseria meningitidis
Authors: Cohen R. L. , Artenstein M. S.
Published: December 2020

A hemagglutination inhibition (HI) test has been studied as an alternative to bacterial agglutination (BA) for serogrouping strains of
Neisseria meningitidis
isolated from clinical specimens. The HI test consists of polysaccharide antigens adsorbed to sheep red blood cells which were then agglutinated by group-specific antisera. Supernatant fluids from suspensions of meningococci were used to inhibit the agglutination. Results of the two tests agreed for 381 (80%) carrier strains. Of the remaining 95 strains, 82 (86%) were identified by HI although they were nongroupable by BA. Thus, the HI test has been shown to be more highly specific and sensitive and to be more economical of reagents and time than the BA test.
Use of the Immunodiffusion Test in the Serodiagnosis of Aspergillosis
Authors: Coleman R. Marie , Kaufman Leo
Published: December 2020

The diagnostic value of an immunodiffusion (ID) test with standardized precipitinogens derived from five
Aspergillus
species was determined with sera from 60 proven and 12 suspected cases of aspergillosis. The data demonstrated that the greatest number of aspergillosis cases were detected by the concurrent use of
A. fumigatus
and
A. niger
precipitinogens. With these precipitinogens, the ID test permitted the serodiagnosis of aspergillosis in 82% of the 60 proven cases and in 83% of the 12 suspected cases. The presence of one or more precipitins was indicative of aspergilloma, of allergic bronchopulmonary aspergillosis, or of invasive aspergillosis. Precipitins were detected in 93% of the sera from patients with aspergilloma, in 50% of the sera from patients with allergic bronchopulmonary aspergillosis, and in 88% of the sera from patients with invasive aspergillosis. Although the presence of one or two precipitin bands could indicate any form of aspergillosis, the presence of three or four was strong evidence of either aspergilloma or invasive aspergillosis. The ID test was found to be 100% specific in an evaluation of its effectiveness with 65 sera from individuals with other systemic mycotic infections, bacterial or neoplastic diseases, and from apparently normal humans. In diagnosed cases of aspergillosis, the examination of serial serum specimens provided information about the clinical course of the disease. A reduction in the number of precipitin bands and significant titer changes were noted as the patients responded to therapy.
Fermenting Yeasts Associated with Softening and Gas-Pocket Formation in Olives
Authors: Vaughn Reese H. , Stevenson Kenneth E. , Davé Bhalchandra A. , Park Hyan C.
Published: December 2020

Fermenting, pectolytic yeasts were isolated from a massive commercial outbreak of softening and gas-pocket formation in olives that had been stored in acidified, low-salt brines in an attempt to reduce the problem of brine disposal. The suspected yeasts represented three different species:
Saccharomyces oleaginosus, S. kluyveri
, and
Hansenula anomala
var.
anomala
. All pectolytic cultures produced pectin esterase and polygalacturonase but no pectic acid
trans
-eliminase when grown in nutrient glucose broth. Crude, cell-free dialyzed enzyme preparations measured viscosimetrically exhibited optimal activity on sodium polygalacturonate at
p
H 6.0 and 45 C and were active in the range of
p
H 4.0 to 9.0 and 10 to 60 C.
Relationships of Temperature and Sodium Chloride Concentration to the Survival of
Vibrio parahaemolyticus
in Broth and Fish Homogenate
Authors: Covert Donna , Woodburn Margy
Published: December 2020

The interaction of temperature and NaCl concentration in affecting the survival of three strains of
Vibrio parahaemolyticus
was studied in Trypticase soy broth and fish homogenate. Cells of
V. parahaemolyticus
suspended in Trypticase soy broth without NaCl were quite unstable and readily killed. The presence of NaCl appeared to be protective to the cells at 48 ± 1 C, with the optimal concentration strain-dependent for the 3 to 12% range tested. Temperatures of 5 ± 1, -5 ± 1, and -18 ± 1 C reduced the number of viable organisms per milliliter regardless of the NaCl concentration. In the presence of NaCl, viable cells, in numbers ranging up to 580 per ml, were still detected at the end of 30 days of storage. Similar results were obtained for cells suspended in fish homogenate, except that fish homogenate itself was protective as compared with Trypticase soy broth. This protection was significantly lower than that provided by NaCl in any amount tested.
Batch- and Continuous-Culture Transients for Two Substrate Systems
Authors: Standing C. N. , Fredrickson A. G. , Tsuchiya H. M.
Published: December 2020

Batch growth of
Escherichia coli
in the presence of equal initial concentrations of glucose and a secondary substrate (xylose) is characterized by sequential utilization of the substrates, whereas continuous-culture systems with equal concentrations of the two substrates in the feed are characterized by complete utilization of both substrates at both high and low dilution rates. Such systems at steady state at a low dilution rate, when suddenly shifted to a higher dilution rate, experience a transient drop in population density accompanied by accumulation of the secondary substrate but virtually no accumulation of glucose. Systems at steady state with 200 mg of glucose per liter were found to undergo a transient population decrease and eventual recovery when switched to feed containing 200 mg of a secondary substrate per liter.
Simple Method for the Preparation of Streptococcal Nucleases
Authors: Marker Stephen C. , Gray Ernest D.
Published: December 2020

A simple method for preparation and fractionation of the streptococcal nucleases by polyacrylamide gel electrophoresis is presented. The procedure is carried out with ammonium sulfate-precipitated supernatant fluids from cultures of beta-hemolytic streptococci grown to stationary phase. Electrophoresis on polyacrylamide gel and subsequent elution of the fractionated enzymes allows the preparation of sufficient homogeneous nuclease B for a large number of anti-nuclease B titrations.
Volume Production of Reference Seed Virus and Immune Ascitic Fluids for Six Arboviruses
Authors: Feild Julian , Kalter S. S.
Published: December 2020

Seed virus reagent and control and immune ascitic fluids were prepared for six arboviruses: buttonwillow, epizootic hemorrhagic disease of deer, Turlock, anopheles B, Kern Canyon, and Semliki Forest. Pilot studies were initiated for each reagent to determine a satisfactory method for their production. Results of homologous and heterologous tests are reported.
Heat Resistance of Salmonellae in Concentrated Milk
Authors: Dega C. A. , Goepfert J. M. , Amundson C. H.
Published: December 2020

The heat resistance of
Escherichia coli, Salmonella typhimurium
, and
Salmonella alachua
in milk solutions containing 10, 30, 42, and 51% (w/w) skim milk for total solids was determined. Increased milk-solids level effected a significant increase in the heat resistance of each organism. Although
E. coli
was more heat-resistant than both strains of
Salmonella
in 10% milk, the situation was reversed in 42 and 51% milk. Prior growth temperature was found to exert a profound effect on the heat resistance of
S. typhimurium
. Growth of
S. typhimurium
in 42% milk solids for 24 hr did not greatly enhance the thermal resistance of the organism when heated in a fresh 42% solids concentrate. Application of a partial vaccum during heating greatly diminished the decimal reduction times of
S. typhimurium
and
E. coli
and, in addition, virtually eliminated the protective effect of increased solids level.
Organisms Encountered in Urine Cultures over a 10-Year Period
Authors: Blazevic Donna J. , Stemper Joanne E. , Matsen John M.
Published: December 2020

Urinary isolates from 1961 to 1970 were surveyed. Forty-four different species were encountered in urine cultures. The most frequently isolated were
Escherichia coli, Klebsiella
, enterococci,
Pseudomonas aeruginosa
, and
Proteus mirabilis
.
Microtiter Plate Agglutination Test for
Salmonella
Antibodies
Authors: Barsoum I. S. , Awad A. Y.
Published: December 2020

Similar results were obtained when testing human sera for
Salmonella
antibodies by the tube agglutination test and by the Microtiter plate agglutination test. The plate test was easier to perform and saved time, space, antigen, and serum.
Possible Origin of
Clostridium botulinum
Contamination of Eskimo Foods in Northwestern Alaska
Authors: Miller Lawrence G. , Clark Paul S. , Kunkle George A.
Published: December 2020

Soils from beaches in northwestern Alaska have been found to contain
Clostridium botulinum
type E, providing evidence of one environmental source of food contamination.
Effect of Selected Herbicides on Bacterial Growth Rates
Authors: Breazeale F. W. , Camper N. D.
Published: December 2020

Specific growth rate constants were used to evaluate the effects of selected herbicides on
Erwinia carotovora, Pseudomonas fluorescens
, and
Bacillus
sp. Comparison of growth rate constants permitted the identification of either stimulatory or inhibitory effects of these substances.
E. carotovora
was inhibited by 6,7-dihydrodipyrido(1,2-a:2′-c)pyrazinediium (diquat) and 4-hydroxy-3,5-diiodobenzonitrile (ioxynil) at 25 μg/ml; 1,1′-dimethyl-4,4′-bipyridinium (paraquat) at 50 μg/ml; and pentachlorophenol (PCP) at 10 μg/ml.
P. fluorescens
was inhibited by paraquat and PCP at 25 μg/ml and by 4-amino-3,5,6-trichloropicolinic acid (picloram) at 50 μg/ml. Stimulation of
P. fluorescens
was observed with 4-(methylsulfonyl)-2,6-dinitro-
N,N
-dipropylaniline (nitralin) at 25 μg/ml. The
Bacillus
species was inhibited by diquat (25 μg/ml), ioxynil (10 μg/ml), and paraquat and PCP (5 μg/ml). No significant effect of 2-chloro-4-(ethylamino)-6-(isopropylamino)-
s
-triazine (atrazine), 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), α,α,α-trifluoro-2,6-dinitro-
N,N
-dipropyl-
p
-toluidine (trifluralin), or 1,1-dimethyl-3-(α,α,α-trifluoro-
m
-tolyl)urea (fluometuron) on growth rates of the bacteria was observed at 25 and 50 μg/ml.
Further Studies on the Anti-Immunoglobulin G Hemagglutination-Inhibition Test for Influenza
Authors: Hahon Nicholas , Booth James A. , Eckert Herbert L.
Published: December 2020

Incorporating species-specific anti-immunoglobulin G (IgG) serum into the hemagglutination-inhibition (HI) test for influenza markedly increased sensitivity without loss of specificity. The effectiveness of anti-IgG serum for augmenting antibody titers may be influenced by the variable potency of commercial anti-IgG preparations. Maximal enhancement of HI titers was achieved when anti-IgG serum and virus-antiserum mixtures were incubated at 23 C for 10 min. Precision and reproducibility of the test were within acceptable limits. Other conditions likely to affect the test were investigated.
Bacteriological Survey of Fresh Pork Sausage Produced at Establishments Under Federal Inspection
Authors: Surkiewicz Bernard F. , Johnston Ralph W. , Elliott R. Paul , Simmons E. Ruth
Published: December 2020

At the time of manufacture, 75% of 67 sets of finished fresh pork sausage collected in 44 plants had aerobic plate counts in the range of 500,000 or fewer/g; 88% contained 100 or fewer
E. coli
/g; and 75% contained 100 or fewer
S. aureus
/g (geometric means of 10 samples). Salmonellae were isolated from 28% of 529 samples of pork trimmings used for sausage, and from 28% of 560 finished sausage samples. Semiquantitative analysis revealed that salmonellae were at low levels; more than 80% of the salmonellae-positive samples were positive only in 25-g portions (negative in 1.0- and 0.1-g portions).
Rapid Recovery of
Escherichia coli
from Estuarine Water
Authors: Andrews Wallace H. , Presnell Maynard W.
Published: December 2020

The efficiencies of two 24-hr elevated-temperature tests to recover
Escherichia coli
from estaurine water were compared simultaneously with the 72-hr standard methods procedure of the American Public Health Association (APHA). From 1,710 tubes,
E. coli
was recovered 222 times in lauryl tryptose medium incubated at 44 ± 0.2 C for 24 hr, 261 times in an experimental medium incubated at 44.5 ± 0.2 C for 24 hr, and 257 times by the 72-hr APHA method. The number of false positives enumerated was similar in all three tests. The data indicated that
E. coli
in raw seawater could be determined in 24 hr without a significant loss of accuracy.
Use of Aromatic Compounds for Growth and Isolation of
Zoogloea
Authors: Unz Richard F. , Farrah Samuel R.
Published: December 2020

Nine
Zoogloea
strains, were examined for their ability to utilize 35 aromatic compounds. Benzoate,
m
-toluate, and
p
-toluate, as well as phenol,
o
-cresol,
m
-cresol, and
p
-cresol, were utilized by eight strains. These strains exhibited
meta
cleavage of catechol and of methyl-substituted catechols. With the exception of L-tyrosine, none of the aromatic compounds tested supported growth of
Z. ramigera
ATCC 19623. A medium containing sodium
m
-toluate was used to isolate 37 zoogloea-forming bacteria from various polluted environments. The isolates were identified as strains of
Zoogloea
.
Bacterial Cell Production from Hexadecane at High Temperatures
Authors: Sukatsch Dieter A. , Johnson Marvin J.
Published: December 2020

On mineral medium with hexadecane as the sole carbon source, stable mixed bacterial enrichment cultures were obtained from soil inoculum at 25, 35, 45, 55, and 65 C. Cell yields (grams of dry cells per gram of hexadecane) were determined for each of the enrichment cultures grown at the temperature at which they were enriched, and also for the 55 and 65 C cultures grown at various temperatures. In all cases, cell yields decreased with increasing growth temperature. The highest yield obtained at 65 C was 0.26, and the lowest yield obtained at 25 or 35 C was 1.02. Slower growth was observed at higher temperatures.
Reduction of the 20-Carbonyl Group of C-21 Steroids by Spores of
Fusarium solani
and Other Microorganisms. I. Side-Chain Degradation, Epoxide Cleavage, and Substrate Specificity
Authors: Plourde Rosaire , El-Tayeb Ossama M. , Hafez-Zedan Hamdallah
Published: December 2020

The spores of
Fusarium solani
reduced the C
2
-carbonyl group, 1-dehydrogenated ring “A” and cleaved the side chain of 16α, 17α-oxidopregn-4-ene-3, 20-dione (16α, 17α-oxidoprogesterone)(I) to give the following products: 20α-hydroxy-16α, 17α-oxidopregn-4-en-3-one(II); 20α-hydroxy-16α, 17α-oxidopregna-1, 4-dien-3-one(III); 16α-hydroxy-17a-oxa-androsta-1, 4-diene-3, 17-dione (16α-hydroxy-1-dehydrotestololactone)(IV); and 16α, 17β-dihydroxy-androsta-1, 4-dien-3-one (16α-hydroxy-1-dehydrotestosterone)(V). When II was used as a substrate, it was metabolized into III, IV, and V at a slower rate than I. Furthermore, 16α-hydroxy-androst-4-ene-3, 17-dione (16α-hydroxyandrostenedione)(X) was transformed into IV and V. Pregn-4-ene-3, 20-dione (progesterone)(XII) was transformed into androsta-1, 4-diene-3, 17-dione (androstadienedione)(VIII) and 17a-oxa-androsta-1, 4-diene-3, 17-dione (1-dehydrotestololactone)(IX), while 17α-hydroxy-pregn-4-ene-3, 20-dione (17α-hydroxyprogesterone)(VI) was converted into its 1-dehydro analogue (VII) without accumulation of any 20-dihydro compounds. Substrate specificity in the 20-reductase system of
F. solani, Cylindrocarpon radicicola, Septomyxa affinis, Bacillus lentus
, and three strains of
B. sphaericus
are demonstrated. The 20-reductase is active only on steroids having the 16α, 17α-oxido, and Δ
4
-3-keto functions. Evidence of competition between side-chain degrading enzymes and the 20-reductase for the steroid molecule and evidence of side-chain degradation followed by epoxide cleavage (and not the reverse) are presented. A mechanism for the epoxide opening by nongerminating spores of
F. solani
is postulated.
Preparation of Poliovirus Labeled with Phosphorus-33
Authors: Sobsey Mark D. , Lavigne Michael E. , Cooper Robert C.
Published: December 2020

Phosphorus-33 (
33
P), a weak (0.25 Mev) beta-emitting isotope of phosphorus with a half-life of 25 days, has been used to label poliovirus in cell culture. HeLa cell monolayers were depleted of phosphate and then labeled by incubating at 37 C in a medium (LM) containing about 10 μCi of
33
P as orthophosphate per ml. Labeled cells were infected at a high multiplicity with poliovirus type 1 and incubated for 8 hr in LM medium. Virus from infected cells was then concentrated and purified. Virus purity was confirmed by comparison of virus infectivity and radioactivity after CsCl density gradient centrifugation and by observing purified virus preparations with electron microscopy. With the method described, yields of about 10
10
to 5 × 10
10
plaque-forming units (PFU) of highly purified poliovirus with specific activities of about 3 × 10
-4
to 10
-3
disintegrations per min per PFU have been obtained from 1.5 × 10
8
to 3.0 × 10
8
HeLa cells.
Microflora of Soil as Viewed by Transmission Electron Microscopy
Authors: Bae H. C. , Cota-Robles E. H. , Casida L. E.
Published: December 2020

Several procedures were evaluated for separating and concentrating indigenous microorganisms from soil without the occurrence of growth. Electron microscopy of nontangential, thin sections through these cells revealed that all of the cells examined were less than 0.9 μm in diameter, and up to 72% were “dwarf” cells less than 0.3 μm in diameter. Some were small enough that they should not be resolved with the light microscope. Approximately 27% had a fine structure bearing some resemblance to that of a bacterial cyst or microcyst, but this value may be low because cells having their outer layers partially stripped off were not included in the count. Approximately 25% showed a distinct periplasmic space, which often contained stainable material. Other fine structure features are presented together with frequencies of occurrence for the populations examined.
Comparison of the Antigenicity of Phenol and Ethylenediaminetetraacetate Complexes Isolated from Cell Walls of
Salmonella enteritidis
Authors: Chipley J. R.
Published: December 2020

Cell walls of
Salmonella enteritidis
were extracted with phenol and with ethylenediaminetetraacetate (EDTA). Phenol extracts were consistently more antigenic in chickens than EDTA extracts. Differences in the action of EDTA and phenol upon bacterial cell walls were demonstrated by the use of radioisotopes.
Corrected Identification of a Test Organism (ATCC 4352) Previously Thought to be
Escherichia coli
Authors: Brown Claude P. , Wilson Frederic H.
Published: December 2020

A gram-negative test organism (ATCC 4352) previously identified as
Escherichia coli
was found to be
Klebsiella pneumoniae
.
Identification of
N, O
-Dimethylhydroxylamine as a Microbial Degradation Product of the Herbicide, Linuron
Authors: Engelhardt G. , Wallnöfer P. R. , Plapp R.
Published: December 2020

N, O
-dimethylhydroxylamine was identified as a degradation product of linuron formed in the presence of extracts of
Bacillus sphaericus
ATCC 12123 by characterization of its dinitrophenyl derivative.
New Method of Intermittent Feeding in Penicillin Biosynthesis
Authors: Matelovā V. , Břečka A. , Matouškovā J.
Published: December 2020

Under laboratory conditions, penicillin biosynthesis was improved by feeding sucrose and sodium phenylacetate to the fermentation flasks in the form of coated tablets.
Factors Influencing L-Asparaginase Production by
Erwinia aroideae
Authors: Peterson R. E. , Ciegler A.
Published: December 2020

Increased yields of L-asparaginase from
Erwinia aroideae
NRRL B-138 were obtained by medium enrichment techniques coupled with aeration optimization.
Lack of Significant Oncogenicity of Biological Products in Hamsters
Authors: Cox Claire B. , Landon John , Valerio Marion G. , Palmer Amos , Kirschstein Ruth L. , Singer Stanley H.
Published: December 2020

A variety of biological products which included live and inactivated viral vaccines, inactivated rickettsial and bacterial vaccines, toxoids, and a multiple bacterial antigen product did not appear to be oncogenic for newborn hamsters following a single subcutaneous inoculation. The incidence of spontaneous tumors was approximately 4.7%, and this figure was not significantly altered by the inoculation of any of the test materials.
Separation of
Treponema pallidum
from Tissue Substances by Continuous-Flow Zonal Centrifugation
Authors: Thomas Myrtle L. , Clark J. Walter , Cline George B. , Anderson Norman G. , Russell Harold
Published: December 2020

The zonal ultracentrifuge was used for separation of
Treponema pallidum
from large volumes of rabbit testicular syphiloma extracts by continuous-flow centrifugation in a cesium chloride density gradient. The gradient was linear with radius from a density of 1.05 to 1.36 g/ml. Operating speeds were 15,000 rev/min for the continuous-flow phase and 25,000 rev/min for a 30-min banding period. A total of 9 × 10
9
(24.3%) treponemes were recovered from the original extract. Of the treponemes recovered, 88% formed a band at a density of 1.170 to 1.211 g/ml. Within the limits of present methods of assay, these fractions were relatively free from testicular particulates and protein when compared with treponemes recovered after differential centrifugation. Observations of the isolated fractions by dark-field and electron microscopy indicated a lack of gross morphological damage to
T. pallidum
. Their antigenic characteristics were also retained, as evidenced by their ability to react with syphilitic sera in the indirect fluorescent-antibody procedure.
Production of Types A and B Spores of
Clostridium botulinum
by the Biphasic Method: Effect on Spore Population, Radiation Resistance, and Toxigenicity
Authors: Anellis Abe , Berkowitz D. , Kemper D. , Rowley D. B.
Published: December 2020

Spores of three strains each of type A and type B
Clostridium botulinum
were produced both by a biphasic (solid medium overlaid with an aqueous phase) and by a “conventional” (deep broth culture) procedure. Sporogenesis by the biphasic system was more rapid, convenient, and economical, and yielded as many or more heat-resistant (80 C, 10 min) spores per milliliter as by the conventional technique. Of several aqueous phases [thiamine-hydrochloride, yeast extract, (NH
4
)
2
SO
4
] tested with strain 62A, the highest spore colony counts were obtained with 2.0% (NH
4
)
2
SO
4
. The six strains formed maximum spore numbers in 5 to 6 days of incubation. Spores produced by the two methods had essentially equal radiation resistances (D and lag values), and their subcultures gave similar toxin titers (LD
50
values).
Effect of L-Aspartic Acid and L-Glutamic Acid on Production of L-Proline
Authors: Kato Jyoji , Kisumi Masahiko , Chibata Ichiro
Published: December 2020

To elucidate the effect of aspartic acid on growth of
Kurthia catenaforma
during the proline fermentation, this organism was compared with other bacteria with respect to the rate of consumption of aspartic acid, and to the activities of enzymes concerned in the metabolism of aspartic acid. Although no marked difference in enzyme activities was observed, the aspartic acid consumption rate of
K. catenaforma
was markedly higher than that of other organisms. The consumption of glutamic acid by
K. catenaforma
was not detected at 24 hr of culture. The difference between the consumption of aspartic acid and glutamic acid in this strain might result from a difference in permeability to the amino acids. We considered that L-glutamic acid might substitute for L-aspartic acid if the uptake of glutamic acid could be increased. A number of detergents were screened for their effect on consumption of glutamic acid. Cetyltrimethylammonium bromide, sodium laurylphosphate, and polyoxyethylene sorbitan monolaurate were found to increase the transport rate of glutamic acid, but not of aspartic acid. A method of producing L-proline from glutamic acid was established with the aid of detergents.
Comparison of the Substrate Specificities of the β-Lactamases from
Klebsiella aerogenes
1082E and
Enterobacter cloacae
P99
Authors: Marshall Monica J. , Ross G. W. , Chanter K. V. , Harris Anne M.
Published: December 2020

A potent β-lactamase (EC 3.5.2.6) produced by a strain of
Klebsiella aerogenes
(
K. pneumoniae
), 1082E, isolated from a hospital patient, has been examined. Its properties were different from those of most gram-negative β-lactamases previously reported. The enzyme has been partly purified, and its activity against a range of substrates has been compared with that of the enzyme from
Enterobacter cloacae
(
Aerobacter cloacae
) P99. The
K. aerogenes
enzyme, although predominantly a penicillinase, had a wide range of specificity. In addition to hydrolyzing the cephalosporins, it attacked the normally β-lactamaseresistant compounds methicillin and cloxacillin as well as cephalosporin analogues with the same acyl substituents. The results obtained with the
E. cloacae
enzyme confirmed its cephalosporinase activity and showed that, unlike the enzyme from
K. aerogenes
, it was relatively inactive against the penicillins.
Microculture Plaque Assay for Human and Simian Cytomegaloviruses
Authors: Chiba Shunzo , Striker Robert L. , Benyesh-Melnick Matilda
Published: December 2020

The plaque assay for human and simian cytomegaloviruses routinely carried out in 60-mm petri dishes (macrocultures) has been adapted for use in microcultures in flat-bottom 16-mm circular wells of disposable plastic trays. Virus titrations and serum neutralization assays carried out in microcultures yielded reproducible results that were identical to those obtained in macrocultures.
Large-Scale Production of Lambda Bacteriophage and Purified Lambda Deoxyribonucleic Acid
Authors: De Czekala Alice , Luk Daniel , Bartl Paul
Published: December 2020

Large amounts of a heat-inducible phage lambda mutant (λCI857) may be obtained under standardized conditions. The phage is harvested by simple polyethylene glycol (C 6000) precipitation and purified by CsCl density gradient banding. Deoxyribonucleic acid (DNA) is extracted by cold phenol and purified by sucrose density gradient sedimentation to yield a homogenous population of unbroken λ DNA molecules.
Steam Versus Hot-Water Scalding in Reducing Bacterial Loads on the Skin of Commercially Processed Poultry
Authors: Patrick Thomas E. , Goodwin T. L. , Collins J. A. , Wyche R. C. , Love B. E.
Published: December 2020

A comparison of two types of scalders was conducted to determine their effectiveness in reducing bacterial contamination of poultry carcasses. A conventional hot-water scalder and a prototype model of a steam scalder were tested under commercial conditions. Total plate counts from steam-scalded birds were significantly lower than the counts of water-scalded birds immediately after scalding and again after picking. No differences in the two methods could be found after chilling. Coliform counts from steam-scalded birds were significantly lower than the counts from water-scalded birds immediately after scalding. No significant differences in coliform counts were detected when the two scald methods were compared after defeathering and chilling.
Antimicrobial Protection of Moisturized Deglet Noor Dates
Authors: Bolin H. R. , King A. D. , Stanley W. L. , Jurd L.
Published: December 2020

The growth of
Saccharomyces rouxii
and
Saccharomyces mellis
, which are two of the main spoilage organisms of dates, can be inhibited by various treatments. The most effective treatment found in this study that did not affect flavor consisted of a predip of the dates in 2% potassium sorbate solution followed by injection of methyl bromide into the sealed package.
Ammonium, Nitrate, and Total Nitrogen in the Soil Water of Feedlot and Field Soil Profiles
Authors: Elliott L. F. , McCalla T. M. , Mielke L. N. , Travis T. A.
Published: December 2020

A level feedlot, located in an area consisting of Wann silt loam changing with depth to sand, appears to contribute no more NO
3
-
nitrogen, NH
4
+
nitrogen, and total nitrogen to the shallow water table beneath it than an adjacent cropped field. Soil water samples collected at 46, 76, and 107 cm beneath the feedlot surface generally showed NO
3
-
nitrogen concentrations of less than 1 μg/ml. During the summer months, soil water NO
3
-
nitrogen increased at the 15-cm depth, indicating that nitrification took place at the feedlot surface. However, the low soil water NO
3
-
nitrogen values below 15 cm indicate that denitrification takes place beneath the surface.
Modification of Schaefer's Procedure for Serotyping of Organisms of the
Mycobacterium avium-M. intracellulare-M. scrofulaceum
complex
Authors: Reznikov M. , Leggo Janet H.
Published: December 2020

Modifications to the tube-agglutination procedure which Schaefer developed for serotyping of organisms of the
Mycobacterium avium-M. intracellulare-M. scrofulaceum
complex are proposed.
In Vitro Studies on the Isolation of Genital Mycoplasmas from Blood
Authors: Lee Yhu-Hsiung , Bailey Penrhyn E. , McCormack William M.
Published: December 2020

A method is described for the isolation of genital mycoplasmas from clinical blood cultures.
Practical Tray-Rack for Culture Dish Incubation
Authors: Woodward Martin R. , Dolan C. Terrence
Published: December 2020

The modification of cafeteria trays for use as racks for agar dishes is described.
Poria weirii
as a Possible Commercial Source of Peroxidase
Authors: Koenigs J. W.
Published: December 2020

Poria weirii
produced peroxidase in yields amounting to 35% of those obtained from the same weight of horseradish roots. The three isozymes detected were distinct from those of horseradish.
Simplified Storage and Retrieval of Stock Cultures
Authors: Nagel Janice G. , Kunz Lawrence J.
Published: December 2020

Multiple replicate units of stock cultures of certain bacteria and yeasts can be prepared, stored, and retrieved for use with a minimum of effort. The method involves the coating of sterile glass beads with a mixture of equal parts of broth culture and horse blood, and storage of the coated beads in a single, labeled, plastic tube in a mechanical freezer.
Large-Volume Purification of Tumor Viruses by Use of Zonal Centrifuges
Authors: Toplin I. , Sottong P.
Published: December 2020

Large volumes of fluids from selected cell cultures producing ribonucleic acid tumor viruses were processed by a double sucrose density gradient procedure using zonal centrifuges. The primary recovery utilized a Model K continuous-flow zonal centrifuge at 9 to 11 liters/hr. The virus zone from the Model K gradient was further purified on a second gradient in a B-29 rotor. The resulting viral concentrates at 2 × 10
11
particles per ml showed high purity by electron microscopy and gel analysis and were useful reagents in biochemical and immunological studies of the reverse transcriptase enzyme, virus structure, complement fixation, and other virus properties. Similar recovery methods were applied to other tumor virus systems.
Apparent Spontaneous Induction of
Staphylococcus aureus
Isolated from Clinical Sources
Authors: Blouse Louis E. , Mauney Charles U. , Marraro Robert V. , Dupuy Harstry J.
Published: December 2020

Apparent spontaneous induction in staphylococcal strains from two clinical specimens was described. One of the two phages associated with these strains was found useful in typing otherwise untypable strains.
Titration of Adenovirus by Counting Cells Containing Virus-Induced Inclusion Bodies
Authors: Weber Joseph
Published: December 2020

A new method for the titration of adenovirus types 2 and 12 based on the enumeration of viral inclusions in infected cells was devised and evaluated. The technique gave virus titers comparable to those obtained by the plaque assay procedure.
Cultivation of Leptospires: Fatty Acid Requirements
Authors: Johnson R. C. , Walby Judith K.
Published: December 2020

Both the parasitic and the saprophytic leptospires grow well on a pair of fatty acids (one saturated, the other unsaturated) if they contain at least 15 carbon atoms.
Improved Skin Test for Detection of T-2 Toxin
Authors: Wei Ru-Dong , Smalley E. B. , Strong F. M.
Published: December 2020

A modified rat skin test based on dermatitic properties of trichothecenes is described which is quick, convenient, and sensitive to 0.05 μg of T-2 toxin.
Peptonized Milk as an Enumeration Medium for Soil Bacteria
Authors: Larkin John M.
Published: December 2020

Peptonized milk agar with Actidione proved to be superior to either Trypticase soy agar or soil extract agar for enumeration of soil bacteria.
Oropharyngeal Cultures of Patients in Protected Environment Units: Evaluation of Semiquantitative Technique During Antibiotic Prophylaxis
Authors: Johnston Dianne A. , Bodey Gerald P.
Published: December 2020

A semiquantitative culture technique was used to monitor the microbial flora of the oropharynx of 30 patients receiving antibiotic prophylaxis in protected environment units. After institution of antibiotic prophylaxis, the median concentration of organisms in the oropharynx fell by 2 logs but gradually increased by 1 log and then remained stable.
Neisseria
spp.,
Micrococcus
sp., and
Streptococci
were generally eradicated by the antibiotics but were replaced by
Lactobacilli
and yeast. Four of nine enteric organisms persisted despite in vitro sensitivity to the antibiotic regimens. Yeast were cultured from the initial specimens of only 17% of the 30 patients, but they were cultured subsequently from specimens of 80% of the 20 patients who remained in protected environment units for at least 8 weeks.
Isolation and Identification of Xanthotoxin (8-Methoxypsoralen) and Bergapten (5-Methoxypsoralen) from Celery Infected with
Sclerotinia sclerotiorum
Authors: Wu C. M. , Koehler P. E. , Ayres J. C.
Published: December 2020

Methods for the production, isolation, and identification of xanthotoxin and bergapten from celery diseased by
Sclerotinia sclerotiorum
(Libert) de Bary were investigated. The only conditions under which this mold was capable of producing xanthotoxin and bergapten occurred when the mold was actively growing on fresh (metabolizing) celery. Neither compound was found in uninfected celery, in the mold growing on nutrient media, on nutrient media fortified with 30% filter-sterilized celery juice, or on nonmetabolizing celery. Maximal xanthotoxin production of 320 μg per g of dry rotted celery occurred at 20 C, although mycelial growth increased until 30 C. Neither xanthotoxin nor bergapten was found when the mold grew on 11 agricultural commodities other than celery.