bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Media for Selective Isolation of Yeasts from Oral, Rectal, and Burn Wound Specimens
Authors: Smith Rodney F. , Blasi Dianna , Dayton Sandra L.
Published: December 2020

Six media were evaluated to determine their ability to isolate yeasts and inhibit bacteria. The media included the following: Snyder, Snyder tellurite, Sabouraud tellurite, Littman-gentamicin, molybdate, and Mycosel (BBL). Doses of mixed intestinal gram-negative bacilli and enterococci were most effectively inhibited by Snyder tellurite agar.
Klebsiella pneumoniae
was the most common bacterial contaminant of the other media. All six media were comparable in isolating yeasts while preventing the growth of the oral bacterial flora. The selection of a basal fungal growth medium for tellurite incorporation to inhibit bacteria but permit growth of yeasts was affected by pH. The bacteriostatic effect of tellurite was decreased with increasing pH of media while fungistatic action was increased. The arbitrary selection of Snyder and Littman agars to isolate yeast from burn wound cultures demonstrated the need to include a selective medium for these specimens. Blood, phenylethyl alcohol blood agar, and Columbia CN blood agar were all inadequate for isolating yeasts from burns. Growth of a variety of filamentous saprophytic and pathogenic dimorphic fungi grew adequately on four of five selective media tested.
Comparative Study of
125
I- and [
3
H]Acetate-Labeled Antibodies in Detecting Iridescent Viruses
Authors: Bilimoria S. L. , Parkinson A. J. , Kalmakoff J.
Published: December 2020

Radioimmunoassays for detecting cell-associated or released virus are described using either
125
I- or [
3
H]acetate-labeled antibodies. In the first assay system, antigen-antibody complexes were separated from free antibody by centrifugation. Sensitivities of 0.1 μg of iridescent virus could be achieved with either
125
I- or [
3
H]acetate-labeled antibody. In the second assay, the antigen was fixed to cover-slip cell cultures, and then reacted with labeled antibody, unbound radioactivity being removed by repeated washing. Nonspecific binding with this method was 0.5 to 1% of the total radioactivity added and sensitivities of 0.1 or 10 μg were achieved with
125
I and [
3
H]acetate, respectively. Immunoglobulins were labeled at the rate of 1 in 300 for
125
I and 1 in 200 with [
3
H]acetate although there was a 400-fold greater isotopic abundance of
125
I relative to
3
H. The possibility of preparing labeled protein of high specific activity using carrier-free [2-
3
H]iodoacetic acid is discussed.
Factors Influencing the Activity of Sterile Filtered and Heat-Sterilized Trypsin Solutions
Authors: Cook R. A. , Poole G. M.
Published: December 2020

The mode of sterilization (filtration or heat) was found to significantly affect the activity of trypsin solutions. Trypsin activity was substantially reduced in the initial fractions of filtrate passed through asbestos filter pads; heat-sterilized trypsin was satisfactory for transfer of cell cultures grown on glass. Heat-sterilized trypsin may be useful when elimination of filterable organisms is required.
Influence of Viral Envelope on Newcastle Disease Virus Infection
Authors: Young Nancy P. , Ash Ronald J.
Published: December 2020

The adsorption characteristics of Newcastle disease virus (NDV) propagated in chicken cells (NDV-C) and in human cells (NDV-H) were examined. Adsorption experiments performed at different temperatures indicated that virus propagated in a particular cell infected that cell type more readily than did virus propagated in a different host. For example, NDV-C was more efficient in initiating infection of chicken cells at 22 C than was NDV-H; the reverse was true when human cells were employed. The results indicate that infection of susceptible cells by NDV is influenced by the host cell in which the virus was propagated. The data also suggest that NDV may be useful in studies on homologous and heterologous membrane-membrane interactions.
Increased Radiation Resistance of Vegetative
Bacillus pumilus
Authors: Parisi A. , Antoine A. D.
Published: December 2020

A 4.5-fold increase in vegetative cell radiation resistance of
Bacillus pumilus
E601, the internationally recognized biological standard for irradiation sterilization, was obtained by the repeated passage of resistant survivors through successive sublethal doses of
60
Co irradiation. This increase in resistance was accompanied by a corresponding increase in spore resistance through the seventh irradiation passage. By the fifteenth passage, the ability for spore formation was lost. Other effects noted by the successive irradiation dosages included loss of motility and pellicle formation, and changes in the Gram reaction, cell morphology, and colonial morphology. Increased resistance was also accompanied by an increased nutritional requirement for specific amino acids. Radiation resistance was not transferred from vegetative cells to spores.
Occurrence of a Complex Form of Staphylokinase in the Course of Cultivation of
Staphylococcus aureus
Authors: Fujimura Setsuo , Makino Toshikazu , Hayashi Takayoshi T. A.
Published: December 2020

Proteins in the culture supernatant of
Staphylococcus aureus
PS 47 were subjected to Sephadex chromatography. In the early stage of the cultivation, staphylokinase appeared to have a molecular weight of 15,000 and in the later stage it appeared to have a molecular weight of 320,000. The staphylokinase having a lower molecular weight (type A) converted into one having a higher value (type B) during the course of cultivation. It was demonstrated that conversion of type A into type B took place in vitro (monitored by gel filtration after the two types of staphylokinases were mixed), and it was observed that type B reverted to type A when type B was treated with KCl or detergent. Type B seems to be a complex form of type A and some high-molecular-weight substance.
Effect of Growth Rate and Nutrient Limitation on the Composition and Biomass Yield of
Acinetobacter calcoaceticus
Authors: Abbott Bernard J. , Laskin Allen I. , McCoy C. J.
Published: December 2020

Acinetobacter calcoaceticus
was grown on ethanol in a chemostat as a model system for single-cell protein production. The substrate yield coefficient (

Y
s

, grams of biomass/gram of ethanol), protein yield coefficient (

Y
p

, grams of protein/gram of ethanol), and biomass composition were measured as a function of the specific growth rate. Nucleic acid, protein,

Y
p

, and

Y
s

all increased at higher growth rates. Although protein content increased only 14% (from 53 to 67%),

Y
p

almost doubled over the same range of growth rates. The increase in

Y
p

was due to the higher protein content of the biomass and to higher values of

Y
s

. The higher values of

Y
s

were attributed to maintenance metabolism, and the value of the maintenance coefficient was found to be 0.11 g of ethanol per g of cell per h. When
A. calcoaceticus
was cultivated under a phosphorus limitation protein content,

Y
p

and

Y
s

were lower than in carbon-limited cultures. It was concluded that a single-cell protein fermentation using
A. calcoaceticus
should be operated at a high growth rate under ethanol-limiting conditions in order to maximize both the protein content of the biomass and the amount of biomass and/or protein made from the substrate.
Hemin Replaces Serum as a Growth Requirement for
Naegleria
Authors: Band R. Neal , Balamuth William
Published: December 2020

Four strains of
Naegleria gruberi
were grown axenically without serum. Serum was replaced by hemin or two selected hemoproteins. Aside from the utility of eliminating serum from the culture medium, the present work shows that
Naegleria
does not require intact protein, and establishes a specific micronutrient requirement for this amoebo-flagellate.
Simple, Inexpensive Procedure for the Disruption of Bacteria
Authors: Ranhand Jon M.
Published: December 2020

Small volumes (1 to 2 ml) of bacterial cultures, with turbidities ranging from 3 to 10, were disrupted 50 to 90% (measured as a decrease in turbidity) within 2 min, by shaking them on a Vortex-type mixer in the presence of glass beads. This method of disrupton was effective for cells in the following genera:
Streptococcus, Lactobacillus, Staphylococcus, Bacillus
, and
Escherichia
. After low-speed centrifugation, the resulting extract can be used as potential sources for enzymes, transforming deoxyribonucleic acids, cell walls, membranes, etc.
Comparison of Purified Alpha-Toxins from Various Strains of
Staphylococcus aureus
Authors: Goode Ronald L. , Baldwin Jack N.
Published: December 2020

Alpha-toxin from five strains of
Staphylococcus aureus
, including Wood 46, was purified by isoelectric focusing. The alpha-toxins obtained from different strains were similar. The isoelectric point of the purified toxins was 8.65 ± 0.15. Sharp concentration peaks were not always obtained. In the ultracentrifuge the alpha-toxins migrated usually as three peaks which could be dissociated with propionic acid to yield one peak. A single line of identity was obtained in immunoelectrophoresis when a heterologous antiserum was reacted with the five purified toxins. It was concluded that the widespread use of the Wood 46 strain for the production of alpha-toxin is justified.
Bacteriocin Susceptibility of
Clostridium perfringens
: a Provisional Typing Schema
Authors: Mahony D. E.
Published: December 2020

Ninety-four strains of
Clostridium perfringens
were examined for bacteriocin production. Bacteriocins produced by ten of these strains were selected for typing 274 cultures of
C. perfringens
. The bacteriocins were prepared by growing the producer strains in broth and precipitating the active principle from the supernatant fluids of centrifuged cultures with ammonium sulfate. All bacteriocins were titrated against a common indicator strain, adjusted to equivalent titers, and spotted onto blood agar plates seeded with the test organisms. Fifty different bacteriocin sensitivity patterns were observed. These patterns were organized into seven groups bearing some relationship, and the largest number of strains falling into any one pattern did not exceed 16% of the total strains tested. Ninety-nine percent of all isolates were typable. The new method should prove useful in studies where strains must be fingerprinted.
Nocardia caviae
: a Report of 13 New Isolations with Clinical Correlation
Authors: Causey William A.
Published: December 2020

Thirteen isolates of
Nocardia caviae
from 12 different clinical sources were received and identified over a 5�-year period by the Mycology Division of the Center for Disease Control. The results of morphological, biochemical, and physiological studies on these isolates were compared with those obtained with four reference cultures of
N. caviae
received from the Institute of Microbiology, Rutgers University. Comparison showed that
N. caviae
isolates form a homogeneous group that is usually easily distinguished from
N. asteroides, N. brasiliensis
, and other pathogenic aerobic actinomycetes. The clinical sources included nine human and two animal infections and one human isolate apparently not associated with disease. Previous reports of
N. caviae
infections in man have been limited to rare cases of actinomycotic mycetoma. Among the human infections reported in this series are one case of mycetoma, one case of “mycotic” keratitis, one case of skin abscess, two cases of osteomyelitis, and four cases of serious pulmonary infection caused by
N. caviae
.
Identification of Group B Streptococci by Immunofluorescence Staining
Authors: Romero Redolfo , Wilkinson Hazel W.
Published: December 2020

Gamma globulin fractions of rabbit antisera prepared with whole cell vaccines of group B types Ia, Ib, II, and III and labeled with fluorescein isothiocyanate stained group B streptococci type specifically. Type Ic cells, which contain the Ia polysaccharide antigen of type Ia and the Ic protein antigen of type Ib, were specifically stained by both Ia and Ib conjugates. A group B conjugate pool (B pool) that contained one conjugate specific for each group B type at its predetermined titer gave positive fluorescent-antibody (FA) reactions (4+ intensity) with group B stock strains and negative FA reactions (less than 2+ intensity) with stock strains of streptococcal groups A, C through H, and K through U, viridans streptococci,
Streptococcus pneumoniae, Staphylococcus aureus, Neisseria gonorrhoeae
, and representative
Enterobacteriaceae
. Examination of 883 clinical isolates submitted to the Streptococcus Laboratory (Center for Disease Control, Atlanta, Ga.) for identification revealed a 99.1% agreement between FA and culture-precipitin methods. All 305 group B streptococci identified by culture-precipitin and six nonhemolytic group B streptococci missed initially by culture tests were identified correctly by FA. Results of cultural and FA methods in a double-blind study of 99 vaginal swabs agreed on 96 of 99 strains. Three nonhemolytic group B streptococci were identified first by FA and later confirmed by culture-precipitin tests.
Microbial Decontamination of Parathion and
p
-Nitrophenol in Aqueous Media
Authors: Munnecke Douglas M. , Hsieh Dennis P. H.
Published: December 2020

A mixed microbial culture was adapted to growth on parathion to determine the feasibility of using microorganisms to detoxify concentrated parathion in agricultural wastes. In a 600-ml chemostat, the culture was able to degrade 50 mg of parathion per liter per h. Para-nitrophenol, produced by enzymatic hydrolysis of parathion, caused delays in exponential growth which were directly proportional to its concentration. A pseudomonad, isolated from the mixed culture, exhibited optimal growth at 0.21 mM
p
-nitrophenol and grew in concentrations up to 3.5 mM. In metabolic studies using [
14
C]
p
-nitrophenol, the nitro group was removed in stoichiometric quantities as nitrite and hydroquinone was tentatively identified as a metabolite.
Storage of Stock Cultures of Filamentous Fungi, Yeasts, and Some Aerobic Actinomycetes in Sterile Distilled Water
Authors: McGinnis M. R. , Padhye A. A. , Ajello L.
Published: December 2020

Castellani's procedure for maintaining cultures of filamentous fungi and yeasts in sterile distilled water was evaluated. Four hundred and seventeen isolates of 147 species belonging to 66 genera of filamentous fungi, yeasts, and aerobic actinomycetes were maintained in sterile distilled water at room temperature over periods ranging from 12 to 60 months in four independent experiments. Of the 417 cultures, 389 (93%) survived storage in sterile distilled water. The selection of good sporulating cultures and sufficient inoculum consisting of spores and hyphae suspended in sterile distilled water were the most important factors influencing survival in water over a longer period of time. The technique was found to be simple, inexpensive, and reliable.
Evolution of Dimethylselenide from Soils
Authors: Francis A. J. , Duxbury J. M. , Alexander M.
Published: December 2020

Alcohols, carbonyl compounds, and fatty acids were formed in two glucose-amended soils incubated under argon, but dimethylselenide was evolved under argon only from one, a selenium-rich clay, after the addition of selenite and glucose. Substantial quantities of dimethylselenide were released from the four soils tested when they were incubated with glucose and selenite in air. No dimethylselenide was produced in the selenium-rich clay soil in air if it received glucose but no selenite.
Growth and Metabolic Characteristics of
Mycobacterium paratuberculosis
Authors: Merkal R. S. , Curran B. J.
Published: December 2020

The cultural characteristics of newly isolated strains of
Mycobacterium paratuberculosis
on a variety of media were studied. The mycobactin dependence ascribed to this species of
Mycobacterium
was found to be easily circumvented by incorporation of 1% ferric ammonium citrate in serum or egg yolk media, but the earliest and most abundant growth occurred on serum medium that contained mycobactin and sodium pyruvate. In the presence of ferric ammonium citrate, respiration did not decrease during 5 days; but in the presence of all other agents studied, respiration decreased after the first day.
Liquid Scintillation Radioassay in Disposable Microcentrifuge Tubes: Radioimmune Precipitates and Other Applications
Authors: Schaffer F. L. , Soergel M. E.
Published: December 2020

A simple, economical radioassay system employing disposable polypropylene microcentrifuge tubes was developed. Plastic adapters permitted automatic operation in liquid scintillation spectrometers. Counting efficiencies of
3
H,
14
C,
32
P, and
125
I in liquid scintillation cocktails and of
32
P by Cerenkov radiation (at lower efficiency in absence of added scintillator) were comparable to those in standard vials. Multipurpose use of the microtubes made the system versatile and expedient, e.g., collection of precipitates and radioassay in the same container. Collection of radioimmune precipitates was aided by a carrier inorganic precipitate, Mg
2
P
2
O
7
.
Critical-Point Drying: Rapid Method for the Determination of Bacterial Extracellular Polymer and Surface Structures
Authors: Cagle Gerald D.
Published: December 2020

The relative amount of extracellular polymer which remains about
Azotobacter vinelandii, Zoogloea ramigera, Klebsiella pneumoniae
, and
Diplococcus pneumoniae
after critical-point drying was studied by electron microscopy. The results obtained with this technique are compared to those obtained with methods that illustrate extracellular polymer, such as freeze-etching and ruthenium red staining. Comparative results indicate critical-point drying to be a rapid, reliable method for the determination of capsule-like polymer surrounding bacterial cells. In addition, critical-point drying can be used to observe morphogenetic changes, such as vesicle production.
Reuse of
Salmonella
and
Shigella
Absorbing Cells for Preparing Monospecific
Salmonella
O and
Shigella
Antisera
Authors: Gray Samuel B. , Green James H. , Harrell William K. , Britt Lois , Bolin Richard C.
Published: December 2020

Salmonella
and
Shigella
organisms used as absorbing cells for preparing group-or type-specific
Salmonella
O or
Shigella
antisera may be reused four or more times without qualitatively reducing their capacity to remove undesired antibodies. The cells may be reclaimed by heating in flowing steam or by treatment with N/5 HCl. The former method is preferred.
Paper-Strip Blood-Sampling Technique for the Detection of Antibody to the Plague Organism
Yersinia pestis
Authors: Wolff Katherine L. , Hudson Bruce W.
Published: December 2020

The paper-strip blood-sampling technique was evaluated for efficacy in plague passive hemagglutination tests. It is valuable for widespread serological surveys.
Use of Microculture Plates and the Multiple Automated Sample Harvester for In Vitro Microassay of Bacterial Toxins
Authors: Knudsen Richard C. , Callahan Lynn T. , Ahmed Aftab , Sell Kenneth W.
Published: December 2020

An in vitro cytotoxicity microassay for the measurement of nanogram quantities of
Pseudomonas aeruginosa
exotoxin and
Vibrio cholerae
enterotoxin is described.
Temperature-Induced Changes in the Sporicidal Activity and Chemical Properties of Glutaraldehyde
Authors: Thomas S. , Russell A. D.
Published: December 2020

Freshly prepared 2% acid and alkaline glutaraldehyde solutions were stored at 4, 20, and 37 C. At intervals, samples were removed and changes in pH, ultraviolet spectrum, and sporicidal activity (against
Bacillus pumilus
spores) were recorded. Alkaline solutions stored at 4 C showed little changes in these properties, whereas such solutions stored at 37 C became turbid and showed a decrease in pH, marked changes in ultraviolet spectrum, and an almost complete loss of sporicidal activity. Intermediate results were obtained with alkaline solutions stored at 20 C. In contrast, acid 2% glutaraldehyde solutions (initial pH 3.5) showed comparatively few changes in their properties. Treatment of spores with freshly prepared glutaraldehyde solutions (0.5%) at temperature above 40 C reduced the effect of pH on sporicidal activity.
Sterility of Salmonid Roe and Practicality of Hatching Gnotobiotic Salmonid Fish
Authors: Trust T. J.
Published: December 2020

The ventral surface of spawning salmonid fish was opened aseptically and the roe were removed aseptically. Roe obtained by using this technique were demonstrated to be sterile. Aseptic fertilization and incubation of eggs obtained in this manner resulted in the hatching of gnotobiotic salmonid fish.
Simultaneous Loss of Proteinase- and Lactose-Utilizing Enzyme Activities in
Streptococcus lactis
and Reversal of Loss by Transduction
Authors: McKay L. L. , Baldwin K. A.
Published: December 2020

During studies on spontaneous loss of lactose metabolism in
Streptococcus lactis
C2, it was found that the lactose-negative (
lac
-
) mutants were also proteinase negative (
prt
-
). This pleiotropic effect was observed in
S. diacetilactis
18-16, but not in
S. cremoris
B1. The

lac
-
prt
-

mutants from
S. lactis
C2 were able to grow in milk, but no pH change or measurable protein breakdown occurred. When the milk was supplemented with glucose, a slow decline in pH occurred. Addition of a protein hydrolysate to milk did not stimulate acid production. When both supplements were added to milk, normal growth and pH change were obtained. When the

lac
-
prt
-

mutant of
S. lactis
C2 was transduced with the temperate phage from the

lac
+
prt
+

parent culture, approximately equal numbers of

lac
+
prt
-

and

lac
+
prt
+

transductants were obtained. When the spontaneous

lac
+
prt
-

strain of
S. lactis
C2 was converted to a

lac
-
prt
-

derivative and transduced, similar results were obtained. The co-transduction of the lactose and proteinase markers suggest they are closely associated. The findings indicate that the transducing phage from
S. lactis
C2 can be used to examine the causes of instability in both the lactose and proteinase enzyme systems of this organism.
Effect of Dissolved Oxygen, Temperature, Initial Cell Count, and Sugar Concentration on the Viability of
Saccharomyces cerevisiae
in Rapid Fermentations
Authors: Nagodawithana Tilak W. , Castellano Carmine , Steinkraus Keith H.
Published: December 2020

By using 7 × 10
8
cells of
Saccharomyces cerevisiae
per ml with which 25° Brix honey solutions were fermented to 9.5% (wt/vol; 12% vol/vol) ethanol in 2.5 to 3 h at 30 C, i.e., rapid fermentation, the death rate was found to be high, with only 2.1% of the yeast cells surviving at the end of 3 h under anaerobic conditions. As the dissolved oxygen in the medium was increased from 0 to 13 to 20 to 100% in rapid fermentations at 30 C, there was a progressive increase in the percentage of cells surviving. The ethanol production rate and total were not seriously affected by a dissolved oxygen concentration of 13%, but fermentation was retarded by 20% dissolved oxygen and still further decreased as the dissolved oxygen content reached 100%. When the fermentation temperature was decreased to 15 C (at 13% dissolved oxygen), the rate of fermentation decreased, and the fermentation time to 9.5% ethanol (wt/vol) increased to 6 h. It was found that the higher the temperature between 15 and 30 C, the greater the rate of death as initial cell counts were increased from 1.1 × 10
7
to 7.8 × 10
8
cells per ml. At the lowest level of inoculum, 1.1 × 10
7
cells per ml, there was actual multiplication, even at 30 C; however, the fermentation was no longer rapid. The addition of 15% sugar, initially followed after an hour by the remaining 10%, or addition of the sugar in increments of 2.5 or 5% yielded a better survival rate of yeast cells than when the fermentation was initiated with 25% sugar.
Indirect Hemagglutinating Antibody Response to
Herpesvirus hominis
Types 1 and 2 in Immunized Laboratory Animals and in Natural Infections of Man
Authors: Back Arthur F. , Schmidt Nathalie J.
Published: December 2020

Indirect hemagglutinating (IHA) antibody responses to
Herpesvirus hominis
types 1 and 2 (HVH-1 and HVH-2) were compared to complement-fixing and neutralizing antibody responses in immunized laboratory animals (rabbits, guinea pigs, and hamsters) and in natural infections of man. With the immunized animals, type specificity was seen only in the IHA test and only with antisera produced in hamsters and in the rabbits immunized with HVH-2. In human nongenital infections (considered to be caused predominately by HVH-1), IHA and neutralizing antibodies developed at about the same rate and reached approximately the same levels for HVH-1 and HVH-2. IHA titers tended to be higher than neutralizing antibody titers for both virus types. In genital infections (considered to be caused predominately by HVH-2), there was a rapid IHA antibody response to HVH-2, and the early HVH-2 antibody demonstrable by IHA, but not by neutralization tests, was found to be immunoglobulin M in nature. In genital infections, IHA titers for HVH-2 were markedly higher than neutralization titers, but there was no pronounced difference in neutralizing the IHA antibody titers for HVH-1. Several patients with genital infections fialed to develop IHA antibody for HVH-1. The IHA test possessed no greater sensitivity than did complement fixation or neutralization tests for serodiagnosis of HVH infections. Despite the fact that a number of patients with genital infections produced IHA antibody only for HVH-2, the test was no more effective than the neutralization test in providing a type-specific serodiagnosis of infection, due largely to the fact that the rapid IHA antibody response to HVH-2 prevented demonstration of a further, significant antibody titer increase in a number of cases.
Development of a Selective Enterococcus Medium Based on Manganese Ion Deficiency, Sodium Azide, and Alkaline pH
Authors: Efthymiou C. J. , Joseph S. W.
Published: December 2020

Rogosa broth, without its salt supplement and dissolved in deionized water, was adapted for the selective isolation and enumeration of enterococci. This medium supported good growth of enterococci, but it suppressed growth of other lactic acid bacteria. The sensitivity and specificity of the medium were tested after addition of various increasing concentrations of NaN
3
against known strains of enterococci and other bacteria. Many strains of
Streptococcus faecium
showed low azide tolerance; optimal growth was obtained at a concentration of 0.01% NaN
3
, which totally or partially inhibited unrelated species of lactic acid bacteria. The selectivity of the medium was further increased by pH adjustment to 9.6. Carbonate and Tween 80 were added to overcome partial inhibition of enterococcal growth by the new combination of selective conditions. The final medium was evaluated in agar form in isolations from human and animal feces, polluted water, meat, and dairy products. Counts were obtained after 16 to 17 h of incubation at 37 C. The isolates satisfactorily conformed to the group characteristics of enterococci.
Comparison of the BACTEC System with Blind Subculture for the Detection of Bacteremia
Authors: Caslow M. , Ellner P. D. , Kiehn T. E.
Published: December 2020

One thousand blood specimens were cultured in BACTEC vials containing modified Columbia broth in aerobic, anaerobic, and hypertonic formulations. Radiometric readings and subcultures were performed on aerobic and hypertonic vials at 24 h and 7 days, and on anaerobic vials at 48 h and 7 days. Significant numbers of false-positive BACTEC readings were obtained. Although all positive cultures were eventually detected by the BACTEC, approximately 20% of blood specimens yielding positive subcultures at 24 h did not give positive BACTEC readings until 48 h.
Effect of a Synthetic Dressing Formed on a Burn Wound in Rats: a Comparison of Allografts, Collagen Sheets, and Polyhydroxyethylmethacrylate in the Control of Wound Infection
Authors: Nathan Paul , Macmillan Bruce G. , Holder Ian A.
Published: December 2020

Allograft dressings to control
Pseudomonas
wound infections in rats were studied on surgical wounds and escharectomized burn wounds. The effects of allografts were compared with a collagen sheet (Aviderm) and a synthetic dressing, polyhydroxyethylmethacrylate (Hydron), formed on the wound by mixing the polymer and the solvent. The results indicated that infections in surgical wounds were more easily controlled by dressings than similar contaminations in burn wounds. A procedure was described for the formation of a synthetic dressing directly on the wound from a mixture of polymer and solvent. This type of preparation completely filled the wound area and sealed the edges, preventing further contamination, and gave excellent coverage of the wound. With 24 h of coverage of escharectomized burn wounds, allografts provided the best dressing for reduction of wound organisms. At 96 h of coverage, Hydron and Aviderm produce significant reductions in the
Pseudomonas
resident in the burn wound. The results support the thesis that suitable dressings promote local host defense processes which kill the contaminating bacteria.
Survey on the Incidence of
Yersinia enterocolitica
Infection in Canada
Authors: Toma S. , Lafleur Lucette
Published: December 2020

Data pertaining to 278 cultures of
Yersinia enterocolitica
isolated in Canada are summarized in this paper. Of this amount, 256 were isolated from humans, whereas 22 were of nonhuman sources. The typing of these cultures is presented together with their geographical location.
Y. enterocolitica
serotype O:3 biotype 4, phage type 9b, was practically the only serotype present in the Province of Quebec. This serotype O:3 was also predominant in Ontario, followed by serotypes O:5,27 and O:6,30; other serotypes were seldom isolated. In the central and western areas of Canada,
Y. enterocolitica
was occasionally isolated; the strains were indole-positive, serotypes O:5,27, O:8, and O:4,32.
Sulfate Reduction by a
Desulfovibrio
Species Isolated from Sheep Rumen
Authors: Huisingh Joellen , McNeill J. J. , Matrone G.
Published: December 2020

Several dissimilatory, sulfate-reducing bacteria were isolated from the rumen fluid of sheep fed purified diets containing sulfate. One isolate, strain D, was selected for characterization. This organism is a nonsporeforming, obligately anaerobic, mesophilic, nonmotile, gram-negative, straight rod. Cell-free extracts show absorption maxima for cytochrome
c
3
and desulfoviridin, characteristic of
Desulfovibrio
. Carbohydrates, as a sole carbon source, will support growth. Lactate supports growth in the presence of sulfate, not in its absence, whereas glucose or pyruvate support growth either in the presence or absence of sulfate. The isolate has a deoxyribonucleic acid base composition of 61.2% guanine plus cytosine, which is similar to that of several other species of
Desulfovibrio
; however, it differs from previously described species in morphology, motility, and carbon source utilization. Cell-free extracts of this bacterium exhibit adenosine 5′-triphosphate-sulfurylase, adenosine-5′-phosphosulfate-reductase, and hydrogenase activity. After incubation of cell-free extracts with adenine 5′-triphosphate and
35
SO
4
2-
, adenosine-5′-phosphosulfate rather than 3′-phosphoadenosine-5′-phosphosulfate was shown to be labeled, indicating that the pathway of sulfate reduction in this organism is similar to that of other dissimilatory sulfate reducers. This is the first report of a
Desulfovibrio
sp. isolated from the rumen.

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Contamination of Bacteriological Media by
Leptospira biflexa
Authors: Brendle J. J. , Alexander A. D.
Published: December 2020

Contamination of media with a strain of
Leptospira biflexa
was traced to the deionized water supply. The leptospiral contaminant appeared in media sterilized by filtration through 0.45- and 0.22-μm pore size membrane filters.
Distribution of
Serratia
Species in Clinical Specimens
Authors: Johnson Erious , Ellner Paul D.
Published: December 2020

Eighty-five strains of
Serratia
were speciated. The majority were
Serratia marcescens
and were recovered from a variety of clinical specimens.
S. liquefaciens
and
S. rubidaea
were recovered only from sputum.
Selecting Lysine-Excreting Mutants of Lactobacilli for Use in Food and Feed Enrichment
Authors: Sands D. C. , Hankin Lester
Published: December 2020

Lysine analogues are used to select for lysine-excreting mutants of
Lactobacillus plantarum
. The use of lactobacilli that excrete lysine for the enrichment of foods and feedstuffs by fermentation is discussed. The increase in lysine content of soybean milk by a mutant of
L. bulgaricus
and in silage by
L. plantarum
is shown.
Flat Gel Polyacrylamide Electrophoresis of Porcine Mycoplasmas
Authors: Wreghitt T. G. , Windsor G. D. , Butler M.
Published: December 2020

The flat gel acrylamide electrophoresis technique was standardized and applied to the comparison of four species of porcine mycoplasmas. Clear differences were observed between these species, and differences were seen among the strains of
Mycoplasma hyosynoviae
. The clarity of the patterns and the number of bands developed was influenced by the amount of protein in the extract and the age of the culture. The technique allows the comparison of several protein extracts in parallel without the problems associated with the rearrangement of separate gel columns.
Biology of
Borrelia hermsii
in Kelly Medium
Authors: Stoenner Herbert G.
Published: December 2020

More than 800
Borellia hermsii
in mouse plasma were required for establishment of growth in an artificial medium (Kelly), but only a single organism of a fully adapted strain (25th subculture) was required for a successful subculture. As judged by generation time, maximal concentration in culture, and length and motility of the organism, the process of adaptation extended through at least 11 subcultures. Because the organisms regularly died shortly after the logarithmic growth phase, transfers at 7- to 10-day intervals were required to maintain continuous cultures.
Production of Hormone B by
Achlya heterosexualis
Authors: Barksdale Alma W. , Lasure Linda L.
Published: December 2020

Sexual morphogenesis in
Achlya
, a filamentous water mold, is initiated by two hormones. Hormone A, or antheridiol, is a C-29 steroid. Four stereoisomers of antheridiol have been synthesized. The natural one (antheridiol 22S 23R) and its 7-deoxy 7-dihydro form, when added to an aerated culture of hermaphroditic
Achlya heterosexualis
, stimulated this mold to secrete twice as much hormone B as the untreated control. An unnatural stereoisomer (antheridiol 22R 23S) and fucosterol, however, did not stimulate strain 8-6 in the same way. Methods by which hormone B can be produced in sufficient yield for isolation and characterization are described.
Effect of Four Dispersants on Biodegradation and Growth of Bacteria on Crude Oil
Authors: Mulkins-Phillips G. J. , Stewart James E.
Published: December 2020

Four chemical dispersants, Corexit 8666, Gamlen Sea Clean, G. H. Woods Degreaser-Formula 11470, and Sugee 2 were examined singly and in individual combinations with Arabian Crude Oil (1:1 ratio) at 10 and 25 C for their effects on the growth of bacteria indigenous to local marine waters, the bacterial population composition, and biodegradation of crude oil; in addition, their emulsifying capacities, at approximately 24 C, were determined. None of the dispersants used alone were toxic even at relatively high concentrations (1.25%), although Gamlen Sea Clean and G. H. Woods Degreaser-Formula 11470 did cause an increase in the lag phase which was more pronounced at 10 than at 25 C; addition of the crude oil reduced the lag phase increase. All of the dispersants used alone supported good growth of microorganisms, but qualitative population shifts were caused by the dispersant-oil combinations. The degrees of degradation of the
n
-alkane fraction of the crude oil varied depending upon the dispersant used. Under these test conditions, only Sugee 2, which had the poorest emulsifying capacity, promoted
n
-alkane degradation compared with the values obtained by using the crude oil alone.
Determination of
Bacteroides melaninogenicus
Serogroups by Fluorescent Antibody Staining
Authors: Lambe Dwight W.
Published: December 2020

Fluorescein isothiocyanate-labeled antibody reagents (conjugates) were prepared to one strain of each of the three subspecies of
Bacteroides melaninogenicus: B. melaninogenicus
subsp.
melaninogenicus, B. melaninogenicus
subsp.
asaccharolyticus
, and
B. melaninogenicus
subsp.
intermedius
. These three conjugates were specific; thus, they provided a new serological classification of
B. melaninogenicus
. The three serogroups were designated A, B, and C. Most test strains (98%) isolated from human clinical specimens were assigned to a specific serogroup by immunofluorescence, and the serogroup of these test strains corroborated the biochemical characterization of the three subspecies of
B. melaninogenicus
. The conjugates failed to cross-react with other anaerobes or aerobes tested. This fluorescent antibody technique provided a more rapid classification of the three subspecies of
B. melaninogenicus
than did conventional biochemical methods.
Sorption of Heterotrophic and Enteric Bacteria to Glass Surfaces in the Continuous Culture of River Water
Authors: Hendricks Charles W.
Published: December 2020

A natural population of heterotrophic bacteria, including enterics, was observed to sorb to glass surfaces and multiply during the continuous culture of river water. An initial rate of attachment equivalent to a doubling time of about 2 h was observed with a corresponding increase in the suspended population. After 24 h both the sorbed and suspended populations stabilized with a mass doubling time approximating 100 h at a dilution rate of 0.012/h. On the basis of respiration and degradative enzymatic data, the sorbed microorganisms appeared to be somewhat more metabolically active than the organisms in suspension.
Nalidixic Acid for Enrichment of Auxotrophs in Cultures of
Salmonella typhimurium
Authors: Weiner R. M. , Voll M. J. , Cook T. M.
Published: December 2020

Nalidixic acid kills only growing cells of
Salmonella typhimurium
and can be used to enrich for auxotrophs in populations where prototrophs predominate.
Specificity and Sensitivity of Radioimmunoassay for Hepatitis B Antigen
Authors: Irwin Gilbert R. , Allen Alfred M. , Bancroft William H. , Willhight Milton , Russell Philip K.
Published: December 2020

Sera from a survey of 6,026 people were tested for hepatitis B surface antigen by using radioimmunoassay and counterelectrophoresis. Forty-eight sera (0.79%) were positive by counterelectrophoresis and 152 sera (2.52%) were positive by radioimmunoassay, using the most liberal of the recommended criteria for positivity (i.e., counts 3 standard deviations above the mean). Absorption tests performed on the 152 radioimmunoassay-positive sera showed that 10 (6.6%) were false-positive reactions to guinea pig protein, 74 (48.6%) were due to false-positive reaction(s) with other protein(s) in the test system, and 68 (44.8%) were true positives. There was a strong correlation between the degree of elevation of radioactive counts and the proportions of sera that were true positives; all 49 sera with counts >50 standard deviation units above the mean were true positives, but only 19 (18.4%) of the 103 sera with counts <50 standard deviation units were true positives. A few sera with high counts required absorption with type-specific (type D) antisera. The following conclusions were reached from this study: (i) absorption tests should be run on all radioimmunoassay-positive, counterelectrophoresis-negative sera; (ii) most (about 90%) false positives are not due to anti-guinea-pig protein reactions; and (iii) radioimmunoassay, in combination with absorption tests, yields a modest increase (about 35%) in detection of true positives over use of counterelectrophoresis alone.
Acetylene Reduction (Nitrogen Fixation) by Pulp and Paper Mill Effluents and by
Klebsiella
Isolated from Effluents and Environmental Situations
Authors: Knowles R. , Neufeld R. , Simpson S.
Published: December 2020

High rates of acetylene (C
2
H
2
) reduction (nitrogenase activity) were observed in woodroom effluent from a neutral sulfite semi-chemical mill under aerobic (up to 644 nmol of C
2
H
4
produced per ml per h) and under anaerobic (up to 135 nmol of C
2
H
4
produced per ml per h) conditions. Pasteurized effluent developed C
2
H
2
reduction activity when incubated under anaerobic but not under aerobic conditions. Activities were increased by addition of 0.5 to 3.0% glucose or xylose. Enrichment and enumeration studies showed that N
2
-fixing
Azotobacter
and
Klebsiella
were abundant, and N
2
-fixing
Bacillus
was present. Of 129 isolates of
Klebsiella
from pulp mills, lakes, rivers, and drainage and sewage systems, 32% possessed nitrogen-fixing ability.
Bacillus stearothermophilus
in Soils of Iceland
Authors: Fields M. L. , Lee P. P. Chen
Published: December 2020

Bacillus stearothermophilus
was found in Icelandic soils. Of the 33 strains studied, only four grew at 25 C. Temperatures as high as 27 C in bare soil at a depth of 1 to 1.5 cm were measured at the collection site. However, to demonstrate growth the cultures had to be incubated for 3 weeks, and soil temperatures remained at 27 C only for shorter periods of time.
Modified Laminar Flow Biological Safety Cabinet
Authors: Mcgarrity Gerard J. , Coriell Lewis L.
Published: December 2020

Tests are reported on a modified laminar flow biological safety cabinet in which the return air plenum that conducts air from the work area to the high efficiency particulate air filters is under negative pressure. Freon gas released inside the cabinet could not be detected outside by a freon gas detection method capable of detecting 10
-6
cc/s. When T3 bacteriophage was aerosolized 5 cm outside the front opening in 11 tests, no phage could be detected inside the cabinet with the motor-filter unit in operation. An average of 2.8 × 10
5
plaque-forming units (PFU)/ft
3
(ca. 0.028 m
3
) were detected with the motor-filter unit not in operation, a penetration of 0.0%. Aerosolization 5 cm inside the cabinet yielded an average of 10 PFU/ft
3
outside the cabinet with the motor-filter unit in operation and an average of 4.1 × 10
5
PFU/ft
3
with the motor-filter unit not in operation, a penetration of 0.002%. These values are the same order of effectiveness as the positive-pressure laminar flow biological safety cabinets previously tested. The advantages of the negative-pressure return plenum design include: (i) assurance that if cracks or leaks develop in the plenum it will not lead to discharge of contaminated air into the laboratory; and (ii) the price is lower due to reduced manufacturing costs.
Adhesive Tape: Potential Source of Nosocomial Bacteria
Authors: Berkowitz David M. , Lee Wie-Shing , Pazin George J. , Yee Robert B. , Ho Monto
Published: December 2020

During a 7-day period, a variety of bacteria, including opportunistic ones, were recovered from 23 rolls of adhesive tape being used in a 16-bed intensive care unit. All rolls of tape were sterile when received from the manufacturer. Mixed flora was recovered from a total of 15 rolls, whereas eight rolls yielded pure cultures. Organisms recovered included
Staphylococcus aureus, Pseudomonas aeruginosa
, and various species of
Enterobacteriaceae
. Although no illness or infection arising directly from contaminated adhesive tape has been documented, we feel that a potential source of infection has been identified. Most important is the fact that such tape may contaminate the hands of personnel who handle it. Also, the adhesive tape may directly contaminate a patient since it is widely used to secure artificial airways and various drainage tubes which results in the tape coming into close contact with the mucous membranes lining the patient's respiratory and urogenital tracts.
Clostridium perfringens
in the Environment
Authors: Matches Jack R. , Liston John , Curran Donald
Published: December 2020

Clostridium perfringens
was isolated from samples collected in Puget Sound in the state of Washington and areas considered as possible sources of these organisms to Puget Sound. The distribution of
C. perfringens
in the total
Clostridium
population was determined for fish gut contents and sediments collected in highly polluted and less polluted areas, sewage samples, freshwater sediments, and soils. The greatest numbers of
C. perfringens
were obtained from marine sediments collected near the sewage outfall at West Point. Fewer isolates were made from fish collected from less polluted stations, although the number of
C. perfringens
remained high in sediments from other Puget Sound stations. The proportion of
C. perfringens
in the total
Clostridium
populations varied between 56 and 71% for sewage samples and only 0.4 to 4.1% for freshwater sediments and soil samples. Only 25
C. perfringens
isolates out of 137 from fish guts, or 18%, were identifiable serologically and these fell into 12 groups.
C. perfringens
were fed to fish and the fish were sacrificed after varying lengths of time. The number of
C. perfringens
increased slightly in the gut during the first 24 h and then the numbers decreased rapidly for the next 120 h.
Characterization of
Klebsiella
Isolates from Natural Receiving Waters and Comparison with Human Isolates
Authors: Matsen John M. , Spindler Joyce A. , Blosser Russell O.
Published: December 2020

Two hundred sixty-six strains of
Klebsiella pneumoniae
isolated from natural water sources in geographically diverse areas (Florida, Massachusetts, and Oregon) were analyzed to determine the serotype, biochemical, virulence, and antimicrobial susceptibility differences between these natural strains and human
Klebsiella
isolates. Sixty of 72 defined serotypes were found among 210 typable strains. Geographic patterns were present, but in general were not pronounced among serotypes. Reactions with 28 biochemical tests showed percentage responses which were very similar to the summaries of primarily human
Klebsiella
isolates (as reported by Edwards and Ewing, 1972) and that represented diverse geographic sampling. Virulence studies in representative strains showed no geographic variability and little difference from comparable hospital patient-obtained isolates. In contrast to human hospital isolates, strains demonstrated 90% or greater susceptibility to all antibiotics except ampicillin and carbenicillin; and in further contrast, there was little multiple antibiotic resistance beyond that with ampicillin and carbenicillin.
Comparison of Media for the Isolation of
Haemophilus
species from Cases of Seasonal Conjunctivitis Associated with Severe Endemic Trachoma
Authors: Vastine David W. , Dawson Chandler R. , Hoshiwara Isao , Yoneda Chieko , Daghfous Toufique , Messadi Mohammed
Published: December 2020

Media for isolation of
Haemophilus
sp. from the conjuctiva were compared in an oasis in southern Tunisia where severe trachoma and seasonal epidemic purulent conjunctivitis are common. Of 89 children tested, IsoVitaleX-supplemented chocolate agar yielded
Haemophilus
in 87%, plain chocolate agar in 75%, sheep blood agar with a stab of
Staphylococcus epidermidis
in 74%, and Fildes medium in 58%. Since other microbial pathogens are easily identified in the modified blood agar, it was the most useful single medium.
Mathematical Analysis of the API Enteric 20 Profile Register Using a Computer Diagnostic Model
Authors: Robertson E. Arthur , MacLowry James D.
Published: December 2020

Results for 21 biochemical tests using the API-20 Enteric kit were obtained from the manufacturer's files for 27,820 bacterial isolates. These isolates were identified by the API Profile Register and also by a computer diagnostic model which estimates the relative likelihoods of various identifications. The computer confirmed the identification in the API Profile Register for 99.36% of the isolates. The manufacturer has reviewed areas of the API Profile Register questioned by the computer analysis; a number of resulting modifications to the API Profile Register have been incorporated in an update letter. This computer model provides a convenient and powerful way to interpret a large number of test results for bacterial identification. This study also demonstrates the use of a large collection of isolates to refine the data matrix used by the diagnostic model.