bluuebunny/crossref_metadata_2025 huggingface dataset:
Herellea (Acinetobacter)
and
Pseudomonas ovalis (P. putida)
from Frozen Foods
Authors: Eller Charles
Published: December 2020

Seventeen strains of
Herellea vaginicola (Acinetobacter antitratus)
and 8 of
Pseudomonas ovalis (P. putida)
, isolated from 23 (6.3%) of 364 samples of frozen, foil-pack foods, were identified and characterized morphologically and biochemically.
Herellea
was isolated from 17 foods (4.7%),
P. ovalis
from 6 (1.6%). No
Mima
were found. The food samples included precooked frozen meats, precooked and uncooked frozen vegetables, and uncooked frozen desserts. The bacteria were detected in the food with a procedure used generally for the detection of salmonellae. The pseudomonad simulated the characteristics of
Herellea
on Sellers differential agar, except for the fact that it fluoresced. From consideration of the habitat and pathogenicity of
Herellea
and
Mima,
it is concluded that, although the presence of these bacteria may not be desirable, their significance in food remains unanswered.
Micro Radiometric Method for Study of Acid-insoluble Materials in Monolayer Cell Cultures
Authors: Ziegler Donald W. , Hutchinson Harriet D. , Palmer Erskine L.
Published: December 2020

A simple radiometric procedure for study of acid-insoluble products synthesized in monolayer cell cultures is described. Cell cultures were produced directly on the bottom surface of scintillation vials or on glass cover slips (8 X 30 mm). The cells were labeled and extracted; the radioactivity was determined while the cells remained affixed to the glass surface upon which they were grown. This procedure enabled rapid investigations of certain biosynthetic processes to be carried out by using many individual cell cultures. The method was applied to an investigation of
3
H-thymidine incorporation induced by vaccinia virus in a 5-bromodeoxyuridine-resistant cell line.
14
C-labeling was evaluated as an alternate procedure for cell quantitation.
Vaccinia Neutralization Test Using a Radioisotope Assay for Virus-induced Enzyme Activity
Authors: Ziegler Donald W. , Hutchinson Harriet D.
Published: December 2020

Vaccinia virus induction of a metabolic activity in host cell cultures forms the basis of a new assay for neutralizing antibodies. A direct relationship between the amount of vaccinia virus infecting cell cultures and the induced incorporation of tritium-labeled thymidine into the acid-insoluble fraction of the cells provided an indicator system. A liquid scintillation spectrometer was used to determine radioactivity associated with cell materials, and it provided a method for partial automation of an immunological procedure. Reproducibility of the method was satisfactory, and agreement with conventional vaccinia serum neutralization tests was demonstrated.
Production of Photons in the Bactericidal Effect of Transient Electric Arcs in Aqueous Systems
Authors: Edebo L.
Published: December 2020

The radiation in the visible and ultraviolet regions from submerged, transient electrical arcs was measured with a K
3
Fe(C
2
O
4
)
3
chemical actinometer and was compared to the bactericidal effect obtained with the same electrical arrangements. Photon production and bactericidal effect were obtained at lower voltages with a smaller electrode separation than with a wider one. At higher voltages, both increased with wider electrode separations. The voltages at maximal photon production efficiency coincided with those of maximal bactericidal efficiency. However, the same photon radiation produced by different electrical arrangements did not always yield the same bactericidal effect in the small discharge vessel usually employed. In a larger discharge vessel, the bactericidal effect was closely correlated with the photon production. The efficiency of photon production by transient arcs was smaller than that of germicidal mercury lamps, particularly with respect to wavelengths of great bactericidal activity. The mechanisms of inactivation and their use for practical disinfection purposes are discussed.
Influence of the Conductivity of the Discharge Liquid on the Microbicidal Effect of Transient Electric Arcs in Aqueous Systems
Authors: Edebo L. , Holme T. , Selin I.
Published: December 2020

The microbicidal effect of electrical discharges on microorganisms suspended in the discharge liquid was reduced when the liquid contained high concentrations of inorganic salts (conductivity
k
≥ 5 mmho/cm). A higher discharge voltage and a smaller distance between the submerged electrodes counteracted this reduction. The decrease in the microbicidal effect was accompanied by a change in the electrical current and by a decreased yield of microbicidal photons from the electric discharge.
Staphylococcus aureus
Response to Lysostaphin in Some Fermented Foods
Authors: Metcalf Robert H. , Deibel R. H.
Published: December 2020

The addition of lysostaphin to starting materials for cheese and fermented sausage that were artificially contaminated with
Staphylococcus aureus
resulted in an initial decrease in the staphylococcal flora. In a simulated cheese process, lysostaphin remained with the curd after separation of the whey. In both cheese and fermented sausage samples that were produced experimentally in the laboratory, a significant
S. aureus
population ultimately developed, even in the presence of lysostaphin. Staphylococcal isolates from these treated products were not more resistant to the lytic enzyme than was the parent strain.
Retting of Flax by
Aspergillus niger
Authors: De França F. P. , Rosemberg J. A. , De Jesus A. M.
Published: December 2020

In this study, retting was carried out by
Aspergillus niger
. The
p
H, galacturonic acid (GA), and total reducing sugar were determined; the end point was identified by the classic empirical processes and by the maximal GA content of the retting water. The process gave clear and resistent fibers, and the retting time was similar to that of current industrial processes with bacterial enzymes. Control of total acidity was not required, since the
p
H remained close to neutrality throughout the entire process.
Neisseria lactamicus sp. n., a Lactose-fermenting Species Resembling Neisseria meningitidis
Authors: Hollis Dannie G. , Wiggins Geraldine L. , Weaver Robert E.
Published: December 2020

The biochemical and serological characteristics of lactose-utilizing strains of
Neisseria
were determined. These organisms were found in the nasopharynx of man and grew well on Thayer-Martin Selective Medium. They were compared with
N. meningitidis
to ascertain whether they were variants of this species. Differences between the lactose-using strains and the recognized species of
Neisseria
were considered significant enough to warrant designation of a new species,
Neisseria lactamicus.
This group has not been widely recognized as being separate from
N. meningitidis;
therefore, the normal incidence and clinical significance of these organisms has not been fully established. These organisms are oxidase-positive and positive for β-D-galactosidase activity; they demonstrate fermentation in King Oxidation-Fermentation Medium; and they produce acid from only glucose, lactose, and maltose, of the 27 substrates incorporated in Cystine Trypticase Agar. Individual strains vary in their ability to grow on Nutrient Agar at both 25 and 37 C and in their pigmentation on Loeffler Medium. Results indicated that these organisms are serologically distinct from the
N. meningitidis
serogroups. Only 34 of 116 strains of
N. lactamicus
were smooth and could be tested by slide agglutination. None of the 34 could be grouped as
N. meningitidis
group A, B, C, D, X, Y, or Z. Thirty-one of these strains could, however, be specifically grouped with antisera prepared with
N. lactamicus
strains. Cross absorptions confirmed that
N. lactamicus
is serologically distinguishable from
N. meningitidis.
Volatile Fatty Acids and the Inhibition of
Escherichia coli
Growth by Rumen Fluid
Authors: Wolin Meyer J.
Published: December 2020

Concentrations of volatile fatty acids (VFA) normally found in bovine rumen fluid inhibited growth of
Escherichia coli
in Antibiotic Medium 3. Acetic, propionic, and butyric acids each produced growth inhibition which was markedly
p
H-dependent. Little inhibition was observed at
p
H 7.0, and inhibition increased with decreasing
p
H. A combination of 60 μmoles of acetate, 20 μmoles of propionate, and 15 μmoles of butyrate per ml gave 96, 69, and 2% inhibition at
p
H 6.0, 6.5, and 7.0, respectively. Rumen fluid (50%) gave 89 and 48% inhibition at
p
H 6.0 and 6.5, respectively, and growth stimulation (22%) at
p
H 7.0. Rumen fluid inhibitory activity was heat-stable, was not precipitated by 63% ethyl alcohol, and was lost by dialysis and by treatment with anion-exchange resins but not with cation-exchange resins. These results are consistent with the idea that VFA are the inhibitory substances in rumen fluid. Previous results which indicated that rumen fluid VFA did not inhibit
E. coli
growth were due to lack of careful control of the final
p
H of the growth medium. The
E. coli
strain used does not grow in rumen fluid alone at
p
H 7.0.
In Vitro Effect of Rifampin on Mycobacteria
Authors: Lorian Victor , Finland Maxwell
Published: December 2020

Rifampin inhibited 20 strains of
Mycobacterium tuberculosis
in concentrations of 0.005 to 0.02 μg/ml in 7H-9 broth with Tween 80 and killed all or nearly all of the inoculum in four to eight times greater concentrations. In the same medium without Tween 80, as well as on 7H-10 agar, about 16 to 64 times these amounts were required to produce the same effect. Rifampin was also active against
M. kansasii
and some of the nonchromogenic mycobacteria. The incidence of mycobacterial cells resistant to rifampin within the cultures studied was in the range of one to four per 10
8
to 10
9
colony-forming units with concentrations of 4 to 125 μg of rifampin per ml. Only one of the Battey cultures and that of
M. fortuitum
yielded cells resistant to rifampin at 125 μg/ml but not at 500 μg/ml. The same strains yielded more than double that number of organisms resistant to streptomycin and up to 100 times more organisms resistant to isoniazid. All three drugs stopped the growth or reduced the mycobacterial population in growing cultures after contact for 24 to 48 hr. Complete inhibition of growth was produced by rifampin at 1.0 μg/ml in an average of 6 days and by streptomycin at 5.0 μg/ml in 3 days. After an average contact of 10.7 days with rifampin, five of seven strains resumed growth and all strains began regrowth after exposure to streptomycin for 9.4 days. The marked susceptibility of
M. tuberculosis
and of atypical mycobacteria to rifampin in vitro and the relatively low incidence of resistant mutants suggests that this agent may have clinical usefulness in the treatment of tuberculosis and some other mycobacterioses.
Cation-dependent Flocculation in a
Flavobacterium
Species Predominant in Activated Sludge
Authors: Tezuka Yasuhiko
Published: December 2020

The predominant bacterium of activated sludge classified as belonging to the genus
Flavobacterium
showed good flocculent growth in the presence of both calcium and magnesium ions, although capsular material or gelatinous matrix was not detectable in the flocs. The bacterium accumulated a large amount of poly-β-hydroxybutyrate when grown on glucose, but not on peptone, in spite of good flocculent growth on both substrates. When the flocs formed during growth phase were suspended in deionized water and shaken for a few minutes, they disintegrated perfectly, and a uniformly dispersed cell suspension was obtained. Furthermore, when the dispersed cell suspension thus obtained was added with each of various mineral salts and shaken for a few minutes, the cells flocculated again, the resultant supernatant solution being almost clear. Even if the dispersed cells were killed by heat or treated by trypsin, they did not lose the ability to form flocs when added with mineral salts. Since the electric charge of the cell surface was negative, a possible mechanism of floc formation was suggested as follows: negatively charged surfaces of adjacent cells are bridged by ionic bonds intermediated by cations. The bacterium utilized a relatively wide variety of organic compounds and showed high metabolic activity comparable to that of naturally activated sludge. These properties, along with floc-forming ability, were considered to be factors for making the bacterium predominant in activated sludge.
Separation of the Proteolytic and Streptolytic Components of a
Streptomyces albus
Enzyme Preparation and Their Effect on Streptococcal Cells
Authors: Bray Juanita P. , Bass Joseph A.
Published: December 2020

The complex of enzymes elaborated by a strain of
Streptomyces albus
was separated by Sephadex G-75 column chromatography. Two major and one minor proteolytic peaks and one streptolytic peak were obtained. The streptolytic fraction alone did not cause lysis of the cells, but was highly effective in the presence of small amounts of trypsin or of the proteolytic components of the enzyme complex. Treatment of cells with the purified streptolytic fraction effected release of group carbohydrate and of a trypsin and pepsin-resistant protein antigen which reacted with type-specific antisera.
Intraperitoneal Injection of Mice
Authors: Miner Norman A. , Koehler Jacqueline , Greenaway Laura
Published: December 2020

Steward, Ornellas, Beernink, and Northway (2) reported a 14% error in the placement of intraperitoneal injections of mice. They considered this error inherent in the technique and not simply correctable. We similarly found an error in the intraperitoneal injection of mice and attempted to identify the cause of error by varying such technical procedures as size of needle, site of penetration (through lower left versus lower right quadrant), investigator, angle of needle to the abdominal wall, and speed of injection. None of these technical modifications consistently eliminated or reduced the error of placement.
Antibody Response of Animals to
Mycoplasma pneumoniae
Measured by Latex Agglutination
Authors: Kende Meir
Published: December 2020

The standardization, application, and usefulness of latex agglutination for
Mycoplasma pneumoniae
antibody titration were investigated and compared with tetrazolium reduction inhibition and complement fixation. The sera of guinea pigs and monkeys reacted in a specific fashion, whereas rabbit serum required pretreatment to eliminate its nonspecific agglutinin. Human serum given such pretreatment still contained a nonspecific agglutinin. The latex agglutination procedure compared favorably with complement fixation and metabolic inhibition tests for evaluating vaccine antigenicity.
Growth Stimulation of
Lactobacillus
Species by Lactic Streptococci
Authors: Branen A. L. , Keenan T. W.
Published: December 2020

Cell extracts of
Streptococcus
species important in cheese starters stimulated the growth of
Lactobacillus
species common to Cheddar cheese. All
Lactobacillus
strains employed, with the exception of a strain of
L. casei
, were significantly stimulated by a strain of
S. diacetilactis. L. casei
was highly stimulated by both a strain of
S. lactis
and a strain of
S. diacetilactis
. The stimulant(s) was dialyzable and was partially inactivated by heat. The stimulatory principle was active at 10 C, indicating that the stimulatory effect may be influencing the growth of lactobacilli in Cheddar cheese during curing. Viable
Streptococcus
cells did not inhibit the growth of
Lactobacillus
species.
Microbial Sulfate Reduction and Its Potential Utility as an Acid Mine Water Pollution Abatement Procedure
Authors: Tuttle Jon H. , Dugan Patrick R. , Randles Chester I.
Published: December 2020

The presence of high concentrations of sulfate, iron, and hydrogen (acid) ions in drainage from coal mines and other areas containing waste pyritic materials is a serious water pollution problem. Sulfate can be removed from solution by microbial reduction to sulfide and subsequent precipitation as FeS. A mixed culture of microorganisms degraded wood dust cellulose, and the degradation products served as carbon and energy sources for sulfate-reducing bacteria. Metabolism of carbon compounds resulted in a net
p
H increase in the system. Oxidation-reduction potential (Eh) and temperature and carbon supplements were studied in an effort to accelerate the sulfate reduction process, with the ultimate objective of utilizing the process as a pollution abatement procedure.
Some Active Derivatives of Penicillin
Authors: Brown Loman D. , Zygmunt Walter A. , Stavely Homer E.
Published: December 2020

The antibacterial activities of a number of amide derivatives of penicillin against both penicillin-sensitive and penicillin-resistant cultures were determined. Several of them were found to possess significant inhibitory activity against certain gram-positive bacteria. The amides, although resistant to the destructive action of β-lactamase, did not protect G in competitive experiments. One derivative, the
O
-benzylhydroxamide of penicillin G, was active against six or eight penicillin-resistant strains of
Staphylococcus aureus
(minimal inhibitory concentration, 0.2 μg/ml or less), but was found to have only a minimal in vivo activity against mouse
Streptococcus
infections.
Mechanism and Factors Influencing the Veronal Inhibition of Bacterial Spore Germination
Authors: Sierra Gonzalo , Bowman Aina
Published: December 2020

The inhibitory effect of sodium 5,5-diethyl barbiturate (Veronal) on the L-alanine-induced initiation of germination of
Bacillus subtilis
spores was examined. Veronal reversibly inhibited the initiation of germination by a noncompetitive mechanism. The inhibition was time-independent and it took place whether L-alanine was or was not allowed to permeate the spore before the addition of the inhibitor. The concentration of the inhibitor and the
p
H of the initiation system were important factors determining the effectiveness of Veronal as an inhibitor. The magnitude of the inhibition increased linearly with decreasing
p
H at constant concentration and with increasing concentration at constant
p
H. These results suggest that the inhibition involves a permeability phenomenon related to the access of drug to the active sites in the spore and that the entry of Veronal into the spores is regulated by the concentration of undissociated molecule. At the physiologically important
p
H of 7.4, initiation with alanine in phosphate buffer at high spore densities (about 10
9
spores per ml) was 50% inhibited by 4 mM Veronal, and 8mM Veronal inhibited initiation completely. L-Alanine initiation in tris(hydroxymethyl)amino-methane-hydrochloride buffer was completely inhibited by 5 mM Veronal. The inhibition could be partially reversed by the combined addition of D-fructose, D-glucose, and K
+
. Possible reasons for the failure of otherwise inhibitory concentrations of Veronal to inhibit completely the L-alanine-induced initiation when a combination of fructose, glucose, and K
+
was present and a suggested relationship to two functional roles of L-alanine in the initiation of germination are discussed.
Rapid Identification of Viruses by Indirect Immunofluorescence: Standardization and Use of Antiserum Pool to Nine Respiratory Viruses
Authors: Stevens T. D. , Watkins H. M. S.
Published: December 2020

The indirect fluorescent antibody test employing treated and standardized antisera and conjugated antiglobulin has been used successfully, in conjunction with a technique for growing and staining virus cell systems in situ on microscope slides, in the identification of nine respiratory viruses. By using pooled antisera in a single test, the presence or absence of these viruses was determined in 18 to 45 hr after inoculation of slide microtissue culture.
Potential Use of Surface-active Agents for Controlling
Mycoplasma
Contamination in Animal Cell Cultures
Authors: Reynolds Roberta K. , Hetrick Frank M.
Published: December 2020

Seven nonionic detergents, which were determined to be relatively nontoxic to selected animal cell cultures, were tested for their lethal effect on the GDL strain of
Mycoplasma hyorhinis
. Of the seven detergents tested, five were found to cause complete lysis of the organism in vitro within 24 hr at 37 C. These detergents included Triton WR-1339 and Tweens 20, 40, 60, and 80. When different concentrations of the detergents were tested, Tween 80 was found to be the most effective and Triton WR-1339 the least effective in lysing the mycoplasmata. These same five detergents were used to treat a rat nephroma cell line which was chronically infected with the GDL strain. The mycoplasmata were eliminated from those cultures treated with Triton but they persisted in cultures exposed to the Tween compounds. The Triton-treated cells remained free from infection over a 7-month period, as determined both by cultural methods and fluorescent-antibody staining. The “cure” was effected by treating the cells for either 48 hr with maintenance media containing 1 mg of Triton per ml or for 96 hr with a concentration of 500 μg/ml. Triton was also effective in eliminating the GDL, strain from experimentally infected rat embryo cells after a 48-hr treatment with a concentration of 1 mg/ml. Four other species of
Mycoplasma
, which were completely lysed by Triton in vitro, were not eliminated from experimentally infected cells by a single treatment with Triton, although the severity of the infection was apparently reduced.
Use of Erythrocytes Sensitized with Purified Pneumococcal Polysaccharides for the Assay of Antibody and Antibody-producing Cells
Authors: Baker Phillip J. , Stashak Philip W. , Prescott Benjamin
Published: December 2020

A method was described for the sensitization of erythrocytes with purified type-specific pneumococcal polysaccharide antigens using chromium chloride as a coupling agent. Erythrocytes so sensitized can be used in routine passive hemagglutination and hemolysis tests as well as in the technique of localized hemolysis-in-gel for the detection of specific antibody and specific antibody-producing cells, respectively.
Influence of
p
H and Metal Cations on Aggregative Growth of Non-Slime-forming Strains of
Zoogloea ramigera
Authors: Angelbeck Donald I. , Kirsch Edwin J.
Published: December 2020

Aggregative growth of non-slime-forming strains of
Zoogloea ramigera
was induced by growing the organisms at a depressed
p
H. Calcium and magnesium ion was found to reverse aggregative growth of the organisms. Conversely, aggregation was stimulated when the available inorganic cation concentration of the growth medium was lowered by the use of a chelating agent. The aggregative effects of
p
H depression or cation depletion and the dispersal effects of cation supplementation were observed only during cellular growth. The data suggest that aggregate formation of non-slime-forming strains of
Z. ramigera
may be related to the calcium or magnesium metabolism of the organisms, or both.
Immunogenicity of Nanogram to Milligram Quantities of Inactivated Foot-and-Mouth Disease Virus. I. Relative Virus-neutralizing Potency of Guinea Pig Sera
Authors: Morgan D. O. , Bachrach H. L. , McKercher P. D.
Published: December 2020

Quantitative antigen dose-neutralizing antibody response curves were established in guinea pigs for purified foot-and-mouth disease virus (FMDV), type A, strain 119, inactivated for 48 hr with N-acetylethyleneimine (AEI). Inactivation of FMDV by 0.05% AEI at 25 C occurred without virus degradation and followed first-order kinetics over a 10
8
-fold decrease in plaque-forming units (PFU) extrapolating to 10
-5
PFU/ml at 48 hr. The AEI-treated virus was administered in doses ranging from 10 ng to 2.62 mg, alone or emulsified in oil adjuvant. Sigmoidal dose-response curves were obtained with 160 ng as the minimum effective dose. The maximum effective dose was 163 μg and 2.62 mg or more at 6 and 28 through 84 days postinoculation, respectively. Oil adjuvant had little effect at 6 days postinoculation, but its use markedly increased the amount of neutralizing antibody obtained at the later testing periods.
Hemodialysis Properties of Clindamycin (7-Chloro-7-Deoxylincomycin)
Authors: Cimino James E. , Tierno Philip M.
Published: December 2020

The effect of hemodialysis (Kolff-type machine) on clindamycin blood levels in anuric patients was studied. At 1 hr after oral ingestion of drug, blood levels ranged from 1.23 to 5.17 μg/ml and fell thereafter. Half-times for peripheral removal were 3.36 μg/ml ± 0.22 when subjects were “off” dialysis and 3.14 μg/ml ± 0.09 during dialysis. Their difference was not statistically significant, indicating that hemodialysis does not affect the blood level of clindamycin. In all studies, significant levels of the antibiotic were present at 12 hr.
Delay of Poliovirus Plaque Formation with Use of Fresh Bovine Serum in the Growth Medium of Host Cellsd
Authors: Smull Christine E. , Ludwig E. H.
Published: December 2020

The plaque formation of poliovirus in HeLa cell monolayers was decreased upto 95% when the host cells were subcultured several times in a growth medium containing fresh bovine serum prior to their inoculation with virus. Extended incubation of infected cell monolayers indicated that the inhibition was in the form of a delay in plaque formation rather than a permanent inhibition of it. The inhibitory factor, which was found in most bovine sera, was very unstable and disappeared after storage of the serum at -20 C for a few weeks or at 36 C within a few days. In HeLa-cell monolayers, the fresh serum brought about a decrease in the plaque formation of all three poliovirus types as well as that of poliovirus ribonucleic acid. The plaque formation of poliovirus in monkey heart and HEp-2-cell monolayers was decreased irregularly by the use of fresh serum in the growth medium of these cells. Speculations were made as to the possible mode of action of the bovine serum inhibitor.
Heat-induced Macroconidia Germination in
Microsporum gypseum
Authors: Leighton T. J. , Stock J. J.
Published: December 2020

A method for obtaining purified ungerminated macroconidia is described, and a technique for obtaining 85 to 90% germination of macroconidia under normal nutritional conditions is presented.
Foot-and-Mouth Disease Virus: Stability of Neutralizing Antibody After Freeze-drying and Air-drying
Authors: Fellowes Oliver N.
Published: December 2020

It is possible to stabilize foot-and-mouth disease antiserum by either freeze-drying in bottles or air-drying on paper for periods of 7 months.
Immunofluorescent Identification of
Salmonella typhi
During a Typhoid Outbreak
Authors: Bissett Marjorie L. , Powers Catherine , Wood Ronald M.
Published: December 2020

Immunofluorescence and conventional bacteriological methods were compared for their ability to detect
Salmonella typhi
in 134 fecal specimens from 105 individuals associated with an outbreak of typhoid fever. Smears prepared from untreated fecal material (direct method) and after a preliminary incubation in selenite F broth (delayed method) were tested with an anti-Vi serum conjugated with fluorescein isothiocyanate. The delayed method was more sensitive than the direct method in detecting
S. typhi
. The delayed method was positive in 40 of 41 patients positive by culture methods, but gave positive or questionable reactions in 11 presumably uninfected individuals. The fluorescent-antibody test employing a Vi conjugate is a satisfactory screening procedure for detecting
S. typhi
, but all positives must be confirmed bacteriologically.
Biosynthesis of Pyocyanine by a Paraffin Hydrocarbon-oxidizing Strain of
Pseudomonas aeruginosa
Authors: Lee E. G.-H. , Walden C. C.
Published: December 2020

A paraffin-oxidizing bacterium, designated as
Pseudomonas aeruginosa
ATS-14, was isolated from soil samples obtained from the Athabasca “tar sands.” This strain utilized kerosene as the only carbon source of energy and produced a high concentration of pyocyanine in the culture medium. Aromatic carbons were not attacked, but C
10
to C
17
n
-alkanes were readily oxidized by the pseudomonad and formed pyocyanine. The highest yield of the pigment was obtained from hexadecane and heptadecane.
Comparison of Two Procedures for Detection of
Salmonella
in Food, Feed, and Pharmaceutical Products
Authors: Fantasia L. D. , Sperber W. H. , Deibel R. H.
Published: December 2020

A survey of food, feed, and pharmaceutical products was undertaken to compare an accelerated
Salmonella
detection procedure by enrichment serology (ES) to the traditional procedure outlined in the
Bacteriological Analytical Manual
(BAM). Excellent agreement between the two methods was obtained in the results of 689 test samples involving 35 different products. In addition to being more rapid and simpler to perform, the ES procedure was just as accurate and sensitive as the BAM procedure.
Cometabolism and Gas Chromatography for the Sensitive Detection of Bacteria
Authors: Mitruka B. M. , Alexander M.
Published: December 2020

Salmonella typhimurium, Escherichia coli
, and
Staphylococcus aureus
were grown in media containing one of several halogenated organic acids which the bacteria metabolized but could not use as a major carbon and energy source for growth. Gas chromatographic techniques were employed to detect the presence of low population densities by analysis for products formed by the microorganisms. By virtue of the presence of the cometabolizable halogenated substrate in the medium, the sensitivity of procedures for detecting the presence of
S. typhimurium, E. coli
, and
S. aureus
was increased more than 7,000-, 20,000-, and 1,000-fold, respectively.
Factors Affecting the Passive Hemagglutination Titration: Dilution Loops, Titration Trays, Vibration, Diluents
Authors: Hirata Arthur A. , Grant Dennis S. , Draper Laurence R.
Published: December 2020

Serial dilution with Takatsy loops resulted in exaggerated passive hemagglutination titers with most of the anti-bovine serum albumin sera tested. It appears that certain types of agglutinins adhere to the loop surface and are released only gradually. This adherence, or carry-over effect, was prevented by presoaking loops in gelatin or gelatin-rabbit serum-albumin solutions. Hemolysins did not adhere to loops. In general, hemagglutination reactions performed on plastic trays gave higher titers than those performed in glass test tubes. The quality of the hemagglutination pattern was dependent to a great extent on the type of plastic tray used. As much as a 100-fold difference in titers was obtained depending on the composition of the antiserum diluent. The increase in vibration, in terms of linear displacement (approximately twofold), resulted in an eightfold decrease in titers.
Two-Dimensional Immuno-osmophoresis of Adenovirus Type 7 Antigens
Authors: Vernon S. K. , Rubin B. A.
Published: December 2020

A test is described in which adenovirus type 7 antigens are separated by two successive perpendicular applications of electrophoresis through agar, causing precipitin formation with cationic immune globulins. Three bands produced by adenovirus cultures distinguish among hexon, fiber, and penton antigens.
Lipase of
Mucor pusillus
Authors: Somkuti G. A. , Babel F. J. , Somkuti A. C.
Published: December 2020

Lipase of
Mucor pusillus
NRRL 2543 was recovered with ammonium sulfate precipitation, gel filtration on Sephadex G-75, and anion-exchange chromatography on diethylaminoethyl-Sephadex A-50. Maximal glycerol ester hydrolase (lipase) activity was observed at pH 5.0 to 5.5 and 50 C when trioctanoin and olive oil were used as substrates. The enzyme also showed esterase activity; it hydrolyzed, with the exception of methyl butyrate, all methyl esters tested. A minimum chain length of six carbons appeared to be a requirement for esterase activity, which was maximal at about
p
H 5.5 with methyl dodecanoate (C
12
) as the substrate. Neither the glycerol ester hydrolase (lipase) nor the esterase activity of the enzyme appeared to be affected by thiol group inhibitors, chelating agents, and reducing compounds. On the other hand, hydrolysis of triolein and methyl dodecanoate was arrested to the same extent in the presence of diisopropyl fluorophosphate, which suggested the involvement of serine in the active center of the enzyme. The enzyme remained stable during a 30-day storage at - 10 C.
Evaluation of Plating Media for the Determination of Viable Microorganisms in dental Plaque
Authors: Hunt D. E. , Sandham H. J. , Gilmore R. W.
Published: December 2020

Four agar media were evaluated to determine which one might be most suitable for the determination of the predominant number of viable microorganisms in dental plaque. The highest plate counts and uniformly larger microbial colonies were consistently obtained with Brain Heart Infusion Agar.
Cell Volume Determinations of
Dictyostelium discoideum
Authors: Barravecchio John , Baumann Paul , Wright Barbara
Published: December 2020

The intercellular water present in pellets of centrifuged cell suspensions of the slime mold
Dictyostelium discoideum
was measured at four stages of differentiation.
Isolation of
Staphylococcus epidermidis
from Tobacco
Authors: Perry Jerome J.
Published: December 2020

Staphylococcus epidermidis
has been isolated in significant numbers from growing tobacco leaves. The organism is also present on cured and aged tobacco.
Production of Vitamin B
12
by
Micromonospora
Authors: Wagman G. H. , Gannon R. D. , Weinstein M. J.
Published: December 2020

Various species of
Micromonospora
produced yields of vitamin B
12
activity as high as 11 μg/ml under conditions of shaken flask fermentation.
Interaction Between Red Cell Stroma and Streptolysin O: Inhibition of Cytotoxic Activity
Authors: Mastroeni P. , Misefari A. , Nacci A.
Published: December 2020

A blood red cell stroma extract neutralizes cytotoxic activity of streptolysin O. The component responsible for inhibition was precipitated by 60% ammonium sulfate and by lysozyme.
Portable Ethylene Oxide Sterilization Chamber
Authors: Songer J. R. , Mathis R. G.
Published: December 2020

A portable ethylene oxide sterilization chamber was designed, constructed, and tested for use in the sterilization of embolectomy catheters. The unit can accommodate catheters up to 40 inches (101.6 cm) in length and can be operated for less than 4 cents per cycle. A constant concentration of 500 mg of ethylene oxide per liter of space and holding periods of 4 and 6 hr at 43 and 22 C, respectively, were adequate when tested with
B. subtilis
spores. The estimated cost of construction was $165.00. If temperature control is unnecessary, the cost is approximately $80.00.
Effect of Chloral Hydrate on Methane and Propionic Acid in the Rumen
Authors: Nevel C. J. Van , Henderickx H. K. , Demeyer D. I. , Martin J.
Published: December 2020

Methane production from pyruvate by mixed rumen bacteria in vitro was nearly totally inhibited by chloral hydrate (0.1 μmole/ml of incubation fluid). This effect was accompanied by an accumulation of gaseous hydrogen and an increase in propionic acid production. Infusion of chloral hydrate (4 g/day) into the rumen of a sheep produced the same effects. Evidence is presented for a direct toxic effect of chloral hydrate upon methane bacteria. Results are discussed in terms of fermentation balances.
Tube Dilution Antimicrobial Susceptibility Testing: Efficacy of a Microtechnique Applicable to Diagnostic Laboratories
Authors: Chitwood Lawrence A.
Published: December 2020

A microtechnique for determining antibiotic susceptibilities by the serial dilution method was evaluated in a clinical diagnostic microbiology laboratory. As compared with the standard tube method, an agreement of 94% was achieved for determining minimal inhibitory concentration with ± one tube dilution as the criterion of comparison. The experience with this system suggests that it could easily be incorporated into diagnostic laboratories as a routine procedure.
Microbiological Hydroxylation of Cinerone to Cinerolone
Authors: Tabenkin B. , LeMahieu R. A. , Berger J. , Kierstead R. W.
Published: December 2020

Cinerone [2-(2′-
cis
-butenyl)-3-methyl-2-cyclopenten-1-one] is hydroxylated to cinerolone [2-(2′-
cis
-butenyl)-3-methyl-4-hydroxy-2-cyclopenten-1-one] by a number of streptomycetes, bacteria, and fungi.
Aspergillus niger
ATCC 9,142 and
Streptomyces aureofaciens
ATCC 10,762 were found to be the most effective hydroxylators. The optical activity of the product was found to range from [α]
D
25
0° to -8.6°, depending on the organism and conditions of culture. Two additional hydroxylated products of cinerone have been isolated and identified as 2-
n
-butyl-4-hydroxy-3-methyl-2-cyclopenten-1-one and 2-(2′-
cis
-butenyl-4′-hydroxy)-3-methyl-2-cyclopenten-1-one, respectively.
Bacteriophage Typing as an Epidemiological Tool for Urinary
Escherichia coli
Authors: Parisi Joseph T. , Russell James C. , Merlo Robert J.
Published: December 2020

Phage typing was used to identify strains of
Escherichia coli
isolated from urinary and nonurinary sources. When eight phages isolated in Pennsylvania were used to type 717 cultures from Missouri, 50.3% of 624 urinary isolates and 34.4% of 93 nonurinary isolates were typable. Strains from nonurinary sources were not found commonly in urine. When five additional phages isolated in Missouri were added to the original set of eight phages, 80.4% of 331 urinary isolates were typable. When this set of phages was used to type 552 urinary cultures isolated in California, Minnesota, Ohio, Pennsylvania, Virginia, and West Virginia, 82.0% of the cultures were typable. Some common phage types were found in high incidence among cultures from the different regions. No correlation was found between phage type and the pattern of resistance to antibiotics. Phage typing data were presented also on the number of strains in individual urine specimens and the recurrences of strains in patients with chronic bacteriuria. Of 97 fecal isolates, 75.2% of the cultures were typable, and the most common phage type was observed in high incidence among the urinary isolates from this region. When 75 cultures from nine other genera of enteric bacteria were typed, only the shigellae were lysed. In view of the information obtained by phage typing and the ease and speed with which it can be done, it is suggested that phage typing be considered a new tool in epidemiological studies of urinary tract infections by
E. coli
.
Growth Factor Requirements of
Ruminococcus flavefaciens
Isolated from the Rumen of Cattle Fed Purified Diets
Authors: Slyter L. L. , Weaver J. M.
Published: December 2020

Eight strains of cellulolytic cocci were isolated from a 10
-8
dilution of rumen ingesta and were presumptively identified as
Ruminococcus flavefaciens
. Four strains were isolated from a steer fed a purified diet which contained isolated soy protein, and four strains were isolated from a steer fed a purified diet which contained urea. Certain growth factor requirements of these bacteria were determined. All strains grew with clarified rumen fluid added to the medium. However, fatty acids could substitute for rumen fluid in four strains. Two strains isolated from each steer either required or their growth was stimulated by isobutyric and/or isovaleric and/or 2-methyl-butyric acid. These results indicate that, even when a diet was fed which contained no branched-chain amino acids, the carbon skeleton precursors of branched-chain fatty acids, the cattle were still able to maintain a large population of cellulolytic bacteria that require fatty acids for growth. Therefore, the fatty acids appear to be provided by other bacteria, by protozoa, or by the host animal.
Suppressive Activity of Streptomycin on the Growth of
Mycobacterium lepraemurium
in Macrophage Cultures
Authors: Chang Y. T.
Published: December 2020

The effect of streptomycin on the growth of an obligate intracellular bacterium was studied in a new host-parasite cell system. The system consisted of
Mycobacterium lepraemurium
grown in cultures of mouse peritoneal macrophages. Since these organisms do not grow in bacteriological media, the influence of extracellular bacterial growth can be ruled out. The suppressive activity of streptomycin was observed in a total of five experiments. At the end of 4 weeks, the average number of organisms per macrophage for the controls was 65.7; for cultures with streptomycin at concentrations of 0.5, 1, 5, 10, 50, and 100 μg/ml of medium, it was 45.4, 38.3, 28.7, 22.7, 13.4, and 8.2, respectively. A good dose-response relationship was evident.
M. lepraemurium
which had been treated in macrophage cultures with various concentrations of the antibiotic for 6 to 8 weeks was used to infect fresh macrophages. These cultures were in turn treated with streptomycin. Resistance of the organisms to streptomycin did not occur.
Ultraviolet Red Fluorescence of
Bacteroides melaninogenicus
Authors: Myers M. Bert , Cherry George , Bornside Bette B. , Bornside George H.
Published: December 2020

Under longwave ultraviolet light,
Bacteroides melaninogenicus
fluoresced vivid red on blood-agar plates as well as in chronic cutaneous ulcers and purulent drainage.
Chemotherapeutic Activity of 5-Fluorocytosine Against a Lethal
Candida albicans
Infection in Mice
Authors: Pittillo Robert F. , Ray Brenda J.
Published: December 2020

Numerous strains of
Candida
were inhibited by low concentrations of 5-fluorocytosine in vitro. Marked increase in life span occurred in
C. albicans
-infected mice treated with 5-fluorocytosine.
Modifications in a French Pressure Cell-Laboratory Press System
Authors: Mardon D. N. , Balish E.
Published: December 2020

Two removable steel plates, a shortened valve handle, lengthened outlet nozzle, and an added test tube holder facilitate use of a cell disruption system.
Effect of β-Lactamase Location in
Escherichia coli
on Penicillin Synergy
Authors: Neu Harold C.
Published: December 2020

Resistance to ampicillin in
Escherichia coli
is due generally to the presence of a β-lactamase (penicillinase). Resistant strains have been found to fall into two groups: those with high-level resistance (1,000 μg/ml or greater) and those with low-level resistance (8 to 250 μg/ml). Most of the high-level resistant organisms posses β-lactamases whose synthesis is episomally mediated. These strains release penicillinase from the cell when they are subjected to osmotic shock. Low-level resistant strains do not release the enzyme with osmotic shock. High-level resistant strains are not susceptible to the synergistic action of a penicillinase-resistant penicillin with ampicillin. Seventy eight per cent of low-level resistant strains are susceptible to the synergistic action of ampicillin and oxacillin. The two types of β-lactamases are similar in regard to most properties; both enzymes are subject to competitive inhibition by penicillinase-resistant penicillins. The difference in location in the cell might explain why only some strains of
E. coli
are susceptible to the synergistic action of penicillin combinations.
Extracellular Nuclease Activity of Fish Spoilage Bacteria, Fish Pathogens, and Related Species
Authors: Sadovski A. Y. , Levin R. E.
Published: December 2020

The production of extracellular deoxyribonuclease and ribonuclease by 23 marine and 3 dairy strains of
Pseudomonas putrefaciens,
15 strains of fish-pathogenic fluorescent pseudomonads, 38 strains of fluorescent pseudomonads isolated from haddock, and 34 related organisms was determined by an agar plate method. All strains of
P. putrefaciens
produced both deoxyribonuclease and ribonuclease. Of the other 87 organisms examined, 26.5% produced ribonuclease and 14.5% produced deoxyribonuclease. All organisms which produced deoxyribonuclease also produced ribonuclease. Deoxyribonuclease production by
P. putrefaciens
is suggested as a useful criterion of identity for members of this intense fish spoilage species.
Procedure for the Evaluation of the Virucidal Effectiveness of an Ethylene Oxide Gas Sterilizer
Authors: Sidwell Robert W. , Dixon Glen J. , Westbrook Louise , Dulmadge Elizabeth A.
Published: December 2020

A quantitative, reproducible method was developed for the evaluation of the virucidal activity of test gases. Using this method, we determined the virucidal effectiveness of a Steri-Vac ethylene oxide gas sterilizer. Wool gabardine material was exposed to high concentrations of herpes simplex, vaccinia, parainfluenza, or polio viruses and was processed through the sterilizer. Two time-temperature cycles of the machine, 29 C for 180 min and 60 C for 48 min, were used in separate experiments. The viruses were exposed to the gas when freshly pipetted onto the fabric or when pipetted on the material and allowed to dry 16 to 24 hr. In two experiments carried out under each condition, the virus titers were reduced by the sterilization process to less than detectable limits. These titer reductions were for the herpes virus ≥ 2.7 to 5.0 log, for vaccinia virus ≥ 4.0 to 6.1 log, for parainfluenza virus ≥ 1.8 to 4.9 log, and for poliovirus ≥ 4.9 to 7.7 log. The observed reductions in virus titers were the same whether the virus-contaminated fabrics were sealed in polyethylene packages or held in open petri dishes during exposure to ethylene oxide.
Biological Response of Lactic Streptococci and Lactobacilli to Catalase
Authors: Gilliland S. E. , Speck M. L.
Published: December 2020

Addition of catalase to milk cultures of lactic streptococci resulted in increased rates of acid production, although it had no effect on cultures of lactobacilli. Milk cultures of both streptococci and lactobacilli produced detectable amounts of peroxide, which reached a maximum level in the early period of acid production followed by a drastic decrease as the acid production increased. Pyruvate and reduced glutathione decreased the amount of peroxide formed, but had little effect on acid production by the streptococci. Ferrous sulfate prevented the accumulation of peroxide and stimulated the rate of acid production by the streptococci to a greater extent than did catalase.
Preparation of Concentrated Lactic Streptococcus Starters
Authors: Peebles M. M. , Gilliland S. E. , Speck M. L.
Published: December 2020

Single-strain cultures of
Streptococcus cremoris
were grown in a semisynthetic medium with automatic
p
H control. After centrifugation, the cells were resuspended in sterile nonfat milk (2% of the original volume). There was no significant difference in the maximum population attained when cultures were grown at
p
H values of 5.5, 6.0, or 6.5 with sodium hydroxide as the neutralizer. With ammonium hydroxide as the neutralizer, maximum populations obtained were increased about twofold. In most cases, the acid-producing ability of the culture concentrates was comparable to that of fresh-milk cultures. There was some variation among strains of
S. cremoris
with respect to the effects of different neutralizers and levels of
p
H control on the biological activity of the culture concentrates. The culture concentrates were stored in liquid nitrogen for as long as 231 days without significant loss in biological activity.