bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Chemistry of Staphylococcal Enterotoxin Poisoning in Monkeys
Authors: Crawley Gerald J. , Black John N. , Gray Irving , Blanchard Jack W.
Published: December 2020

Clinical chemistry values were examined in 90 monkeys administered a purified preparation of staphylococcal enterotoxin, type B, intravenously. These studies showed an early release of epinephrine accompanied by a mild increase in blood glucose. This was followed by progressively developing prolonged hypoglycemia. An early increase in bloodurea nitrogen occurred, presumably as a result of both prerenal azotemia and functional renal failure seen in association with the observed hypotension. Serum protein, Ca, and Cl concentrations decreased with time. Pi levels increased, whereas Na and K concentrations in serum remained unchanged. Serum enzyme concentrations were unchanged, with the exception of serum glutamic oxaloacetic transaminase, which rose rapidly when compared with prechallenge control observations or with values from sham-challenged monkeys. These changes were statistically significant. These results suggested that enterotoxin administered intravenously produced early change in glucose metabolism, possibly related initially to catecholamine release and later to increased utilization of glucose and metabolic acidosis. Other findings were compatible with tissue breakdown at as yet undetermined locations and with loss of endothelial membrane integrity, as evidenced by loss of protein from the vascular space.
U-21,963, a New Antibiotic
Authors: Pyke Thomas R. , Dietz Alma
Published: December 2020

A new antibiotic, U-21,963, is produced by a new strain of
Trichoderma viride
. Antibiotic activity can be demonstrated against both gram-positive and gram-negative bacteria and also against a wide variety of fungi. U-21,963 is not cross-resistant with other commonly used antibiotics. U-21,963 afforded no protection against
Klebsiella pneumoniae, Streptococcus pyogenes
, or
Staphylococcus aureus
when it was injected subcutaneously into mice.
Membrane Filtration Technique for Isolating Organisms from Raw Milk of Normal Udders
Authors: Graves Donald C. , Schipper I. A.
Published: December 2020

The effectiveness of two methods for the isolation of bacteria from raw milk was investigated. Raw milk from normal udders was subjected to the direct membrane filtration technique and the 18-hr incubation technique. The results indicate that the membrane filtration technique gives a more complete picture of the flora of a normal udder than does the 18-hr incubation technique. Use of various methods for the isolation of organisms from milk samples may account for the extensive disagreement on the presence and types of organisms associated with normal and mastitic udders.
Kinetic Studies on the Destructive Action of Oxygen on Lyophilized
Serratia marcescens
Authors: Dewald Robert R.
Published: December 2020

Dried
Serratia marcescens
(ATTC strain 14041) cells were exposed to various partial pressures of oxygen and nitrogen. The colony-forming ability of the organisms was rapidly destroyed during exposure to oxygen but was unimpaired by exposure to purified nitrogen. The degree of inactivation depended upon temperature, time, and the partial pressure of oxygen, regardless of whether pure oxygen or dry air was used. The inactivation by oxygen followed the expression -1
nN/N
0
=
k
[O
2
]
1/3
t
1/2
, where
N
0
and
N
are the number of viable organisms before and after exposure respectively, [O
2
] is oxygen concentration,
t
is time, and
k
is the rate constant. At 25 C,
k
was 276 ± 36 moles
-1/3
cc
1/2
hr
-1/3
for oxygen pressures between 5.5 and 258 torr. In the temperature range between -78 and 40 C, the rate constant may be expressed as
k
= 10
5.95±04.2
exp[(-430 ± 26) cal/RT] moles
-1/3
cc
1/3
hr
-1/2
.
Effect of
p
H on Population and Fermentation in a Continuously Cultured Rumen Ecosystem
Authors: Slyter L. L. , Bryant M. P. , Wolin M. J.
Published: December 2020

The effect of
p
H on rumen fermentation and microbial population was studied in a continuously cultured rumen ecosystem. A marked decrease in the production of volatile fatty acids and methane from alfalfa hay occurred when the cultures were maintained at
p
H values below 6.0. The decrease in acetate and methane production was greater than that of propionate production. The culture maintained at
p
H 6.7 contained the types of bacteria often found in high concentration in the rumen, whereas the culture maintained at
p
H 5.0 had a high percentage of bacteria which could not be identified with the major rumen bacteria found in rumens of animals fed alfalfa hay. Replacement of the bicarbonate-phosphate buffer used to maintain fermentor
p
H at 6.7 with phosphate alone did not greatly alter the fermentation products produced from a hay-concentrate substrate.
Antagonistic Effect on
Clostridium botulinum
Type E by Organisms Resembling It
Authors: Kautter D. A. , Harmon S. M. , Lynt R. K. , Lilly T.
Published: December 2020

A bacteriocin-like substance, active against strains of
Clostridium botulinum
type E, is produced by certain nontoxic organisms whose biochemical properties and morphological characteristics are similar to type E. The substance, for which the name “boticin E” is proposed, is bacteriolytic for vegetative cells and bacteriostatic for spores of type E. Its spectrum of activity is somewhat strain-specific. Of the clostridial species tested, only
C. botulinum
type E and, to a lesser extent,
C. perfringens
and
C. acetobutylicum
, but not
C. botulinum
types A, B, or F, are sensitive. Irreversibly resistant variants originating from both vegetative cells and spores of certain strains were obtained. The active substance is heat-stable and dialyzable, and is not inactivated by chloroform but is digested by trypsin. Ethyl alcohol and acetone precipitates are fully active, whereas trichloroacetic acid precipitates are only partially active. Other nontoxic organisms producing similar antagonistic substances are discussed.
Factors Influencing the Occurrence of High Numbers of Iodine-Resistant Bacteria in Iodinated Swimming Pools
Authors: Favero Martin S. , Drake Charles H.
Published: December 2020

It has been shown that, although iodinated swimming-pool waters are usually free from coliform bacteria and enterococci, the total counts frequently become relatively high.
Pseudomonas alcaligenes
and
Alcaligenes faecalis
have been shown to account for most of these high counts. It was of interest, therefore, to compare the microbial flora of four alternately chlorinated and iodinated swimming pools. By means of the membrane filter method and suitable selective media, examinations were made for total viable counts, coliform bacteria, enterococci, staphylococci,
Streptococcus salivarius
, and
P. aeruginosa
. Colonies also were picked from membrane filters incubated on standard plate count agar and identified. The results showed that, although viable counts were significantly higher during the iodinated periods, the specific types of bacteria determined were either fewer than or the same as in chlorinated periods. During chlorination, the predominant microbial flora consisted of staphylococci and members of the genus
Bacillus
. During iodination, however, the
P. alcaligenes-A. faecalis
group accounted for 92 to 99% of the microbial flora. The accumulation of high numbers of these bacteria was shown to be due to their iodine resistance and their ability to grow rapidly in pool water in the absence of free iodine.
Multiplication and Fermentation of
Saccharomyces cerevisiae
under Carbon Dioxide Pressure in Wine
Authors: Kunkee Ralph E. , Ough C. S.
Published: December 2020

Conditions for rapid fermentation of sugar in wine under pressure were sought for use in continuous production of naturally fermented sparkling wine. Wine yeast growth and fermentation were measured under CO
2
pressure. The medium was white wine with added glucose. Pressure was very inhibitory to growth, especially at low
p
H or high alcohol concentration. Use of various strains of wine yeast, cultures of various ages, or cells adapted to wine did not give more rapid growth. Addition of nutrients increased growth, but under no conditions was growth rapid enough to bring about sufficiently rapid fermentation rates. Conditions for rapid fermentation were sought by use of high levels of cells as inocula. Fermentation rates in wine also were inhibited by pressure, and were dependent on
p
H and alcohol levels. Addition of nutrients did not increase the fermentation rate, but rapid fermentation rates were obtained, under pressure, by inoculation with high levels of cells adapted several weeks to the base wine. Thus, continuous sparkling-wine production might be practical with proper amounts of adapted cells used as inocula, or perhaps with reuse of the fermentation culture.
Production of a Pyrrole Antibiotic by a Marine Bacterium
Authors: Burkholder Paul R. , Pfister Robert M. , Leitz Frederick H.
Published: December 2020

Evidence is presented for the isolation and identification of bacteria able to synthesize an unusual antibiotic containing five bromine atoms per molecule. The identification and taxonomic position of these bacteria was made by use of a computer in conjunction with traditional methods. These microorganisms and closely related strains have been isolated on various occasions from tropical water in the vicinity of Puerto Rico. One bacterium, a pseudomonad, has been given the name
Pseudomonas bromoutilis
because of its distinctive capability. The antibiotic has been extracted, purified, and obtained in crystal form, and its structure has been determined. Although clinical tests of its properties were not encouraging, it may be of significant value and interest from an ecological standpoint.
Effects of Inhibition and Repression on the Utilization of Substrates by Heterogeneous Bacterial Communities
Authors: Stumm-Zollinger Elisabeth
Published: December 2020

This investigation attempts to evaluate to what extent enzyme inhibition and repression by metabolites, indigenous to the cell, are significant phenomena in natural microbial communities. Three case histories of the kinetics of substrate utilization and growth in multisubstrate media by heterogeneous bacterial populations are presented: (i) concurrent substrate utilization and growth on both substrates simultaneously (glucose plus benzoate); (ii) sequential substrate elimination accompanied by diauxic growth as a result of inhibition of enzyme activity (glucose plus galactose); (iii) sequential substrate utilization accompanied by diauxic growth caused by repression of enzyme formation (glucose plus
l
-phenylalanine, benzoate plus
l
-phenylalanine). It is shown that enzyme inhibition was observed in two-substrate media as well as in multisubstrate media and was maintained at low substrate concentrations (few milligrams per liter). A special attempt has been made to maintain the diversity of the experimental microbial population during the adaptation and enrichment period. All substrates were determined with sensitive analytical methods specific for the individual substrates. The results obtained confirm that catabolite repression and the resulting sequential substrate utilization are observed in heterogeneous bacterial populations.
Growth and Invasiveness of
Candida albicans
in the Germ-Free and Conventional Mouse After Oral Challenge
Authors: Phillips A. W. , Balish Edward
Published: December 2020

Candida albicans
was established in large numbers throughout the gut after one oral challenge in the germ-free and in the conventional mouse. Of the strains tested, only the germ-free ND 1 mouse appeared to be susceptible to infection, and this was confined to the stomach mucosa; lesions contained large numbers of hyphal and mycelial forms with blastospores. These forms were also seen in the gut of resistant germ-free ND 4 mice after challenge. Only budding yeast forms were seen in the gut contents from conventional animals. The concentration of sulfhydryl-containing compounds was decreased in the stomach contents from germ-free mice. The stomach tissue of conventional animals seemed to be more acidic than that of germ-free animals, and association of
C. albicans
with conventional mice neutralized some of this acidity.
E
h
values of contents from the gut of unchallenged mice were usually higher in conventional than in germ-free animals; after challenge, the
E
h
in both groups decreased. Some reciprocal effects of intestinal microorganisms and host are discussed in relation to intestinal candidiasis.
Effect of Diluent and Relative Humidity on Apparent Viability of Airborne
Pasteurella pestis
Authors: Won William D. , Ross Harold
Published: December 2020

Airborne
Pasteurella pestis
(A-1122) at low humidities [20 to 50% relative humidity (RH)] exhibited exponential decay when either 1% peptone or Heart Infusion Broth (HIB) was used as the diluent in the viable assay system. At higher RH values (65 and 87%), however, the 1% peptone diluent adversely affected the viability assay. In contrast, HIB as diluent was remarkably effective in demonstrating a higher number of viable cells in aerosols held at high RH values. Similarly, with HIB as diluent, aerosols were shown to contain viable cells during 90 min of observation; with 1% peptone, viability was not detectable after 20 min in the airborne state.
Solubilization of Acid-Swollen Cellulose by an Enzyme System from a Species of
Alternaria
Authors: Logan Robert M. , Siehr Donald J.
Published: December 2020

An unknown species of
Alternaria
, when grown on a medium containing carboxymethylcellulose as a carbon source produced a mixture of extracellular enzymes which solubilized acid-swollen cellulose. The product of the hydrolysis was a 1:2 molar mixture of cellobiose and glucose. The organism apparently produced no cellobiase. It is suggested that the mixture of cellulolytic enzymes contains at least two different enzymes which degrade cellulose in an endwise manner.
Effect of Aeration on Growth and Aflatoxin Production by
Aspergillus flavus
in Submerged Culture
Authors: Hayes A. Wallace , Davis Norman D. , Diener Urban L.
Published: December 2020

Aspergillus flavus
ATCC 15517 produced up to 212 mg per liter of total aflatoxin in submerged culture in aerated (3,000, 6,000, 9,000, and 12,000 ml/min) and agitated medium in 14-liter fermentors with 10 liters of medium consisting of 2% yeast extract and 10% sucrose. Aflatoxin production increased with time. A maximum of 212 mg/liter was produced at 9,000 ml/min aeration, whereas the yield decreased substantially at the lower aeration rates. Two other strains of
A. flavus
synthesized aflatoxin in smaller quantities.
Statistical Evaluation of Electronic and Plate Counts for Estimating Bacterial Populations
Authors: Mountney G. J. , O'malley J.
Published: December 2020

Bacteria from cultures of
Staphylococcus aureus, Pseudomonas geniculata
, and
Rhodotorula glutenis
were counted by use of an electronic counter and by plate counts from broth cultures at selected periods from 0 to 24 hr. Variations in the two methods were noted, and the results were compared after calculating correlations, coefficients of variation, and nested analyses of variance. It was not possible to determine the absolute accuracy of the two methods; however, the precision of the results obtained with an electronic counter was better than that obtained with plate counting. It appears that electronic counting, because of ease and convenience, provides better comparative counts at a particular stage of growth, especially during the early stages of the growth period, whereas plate counting yields the best results in determining growth curves.
Adaptation of
Pseudomonas fluorescens
to Low Levels of Water Activity Produced by Different Solutes
Authors: Limsong Somluck , Frazier W. C.
Published: December 2020

A culture of
Pseudomonas fluorescens
which grew at a minimal
a
w
of 0.97 in a glucose-salts broth adjusted to that level with NaCl, KCl, or glucose, and at
a
w
0.9725 with Na
2
SO
4
, was adapted to grow at lower
a
w
levels produced by these solutes. Adaptation to growth at a low
a
w
produced by means of one solute did not necessarily result in growth at that
a
w
when another solute was employed to lower the
a
w
. The culture adapted to grow at
a
w
0.9650 produced by addition of glucose could grow equally well in broth adjusted to that
a
w
with NaCl or KCl, but not Na
2
SO
4
. NaCl and KCl permitted growth at the lowest
a
w
level (0.9625), and the culture adapted in KCl did equally well in NaCl.
Effect of Electrostatic Charge on the Contamination of Plastic Food Containers by Airborne Bacterial Spores
Authors: Baribo Lester E. , Avens John S. , O'Neill Richard D.
Published: December 2020

Electrostatic charge of approximately -10 kv was produced by friction on polystyrene food container samples. This charge quickly decayed to a lower, more stable, level. Exposure of samples to positively charged red and negatively charged green fluorescent particles resulted in a particle-distribution pattern on the plastic surface. The dynamic attraction of fluorescent particles was illustrated by time-lapse photography. Similar distribution patterns of airborne bacterial spores were shown to develop. In controlled bacterial aerosol exposure tests, an increase in surface contamination of the plastic samples was found to be quantitatively related to an increase in negative electrostatic charge on the plastic. Static charge was found to accumulate on plastic food containers during their manufacture, and to remain indefinitely on many of the finished products. This charge was of the intensity and polarity to attract positively charged bacterial cells if such particles were present in the air.
Microbial Detoxification of Aflatoxin
Authors: Ciegler A. , Lillehoj E. B. , Peterson R. E. , Hall H. H.
Published: December 2020

Yeasts, molds, bacteria, actinomycetes, algae, and fungal spores were screened for their ability to degrade aflatoxin. Some molds and mold spores partially transformed aflatoxin B
1
to new fluorescing compounds. Only one of the bacteria,
Flavobacterium
(
aurantiacum
?) NRRL B-184, removed aflatoxin from solution. Both growing and resting cells of B-184 took up toxin irreversibly. Toxin-contaminated milk, oil, peanut butter, peanuts, and corn were completely detoxified, and contaminated soybean was partially detoxified by addition of B-184. Duckling assays showed that detoxification of aflatoxin solutions by B-184 was complete, with no new toxic products being formed.
Sensitive Rapid Detection Method for Viable Bacterial Cells
Authors: MacLeod Robert A. , Light Marilyn , White Lloyd A. , Currie J. F.
Published: December 2020

A rapid sensitive method for the detection of viable bacterial cells is described in which P
32
as inorganic orthophosphate is used to label the cells. Factors affecting the uptake of P
32
by cells as well as the sensitivity of the method have been explored with suspensions of
Aerobacter aerogenes
. The uptake of P
32
O
4
is dependent on several factors. Of various incubation media tested, one composed of 0.005
m
KCl, 0.002
m
MgSO
4
and 10 mg/ml of glucose was found to best stimulate the uptake of the tracer. Incubation time and temperature and level of isotope and of unlabeled P also affected uptake. Labeled cells were collected on a membrane filter for measurement of radioactivity. Under optimal conditions, as few as 23 viable cells per milliliter were detected in 1 hr with 95% confidence.
β-Propiolactone Vapor Decontamination
Authors: Hoffman Robert K. , Buchanan Lee M. , Spiner David R.
Published: December 2020

Although β-propiolactone (BPL) is an effective vapor-phase decontaminant for enclosed areas, some problems have been encountered in its use. Adequate air circulation during BPL dissemination could eliminate most of these problems. It is recommended that, when decontaminating the ordinary building or laboratory, the amount of BPL sprayed be changed from the previously suggested 1 gal/16,000 cubic ft of space to 1 gal/25,000 cubic ft. The use of aqueous BPL solutions and thermal-type generators is not recommended.
Bacteriological Survey of the Frozen Prepared Foods Industry
Authors: Surkiewicz Bernard F. , Hyndman James B. , Yancey Mary V.
Published: December 2020

During inspection of 21 frozen breaded raw shrimp processors, 861 finished product units (retail packages) and 778 line samples were collected and analyzed bacteriologically. The bacteriological results for the finished product samples collected in plants with poor and good sanitary controls are presented and compared. The samples consisted of 4 to 38 units (retail packages) of the finished product as offered for sale by the processors. Frozen raw breaded shrimp collected from plants operating under good conditions of sanitation had the following bacterial contents: 85% of the samples had an average (geometric) aerobic plate count of less than 1,000,000 per gram; all of the samples had an average (geometric) most probable number of less than 1,000 coliforms per g; 81% of the samples contained less than 20%
Escherichia coli
-positive units; 57% of the total number of units in 0.1-g portions were negative for coagulase-positive staphylococci, and 95% of the units had less than 1,000 coagulase-positive staphylococci per gram.
Instrumental Assay of Microbial Lipase at Constant
p
H
Authors: Clemente Charles L. San , Vadehra Dharam V.
Published: December 2020

A rapid, accurate method with high sensitivity and reproducibility, and having the advantage of a short incubation period under constant
p
H, has been developed for routine measurement of microbial lipase. Assembled from readily available and economical instrumental components, the apparatus includes a
p
H meter, a thermoelectric heating and stirring device, a motor-driven burette, and an automatic recorder. The reaction mixture, consisting of 5 ml of a 10% olive oil-gum arabic emulsion, 2 ml of 3
m
NaCl, 2 ml of sodium taurocholate (15 mg/ml) of 0.075
m
CaCl
2
, 5 ml of water, and 1 ml of enzyme solution, was adjusted to
p
H 8.0 and 37 C. The
p
H was maintained at a constant value by automatic addition of 0.01
n
NaOH during the incubation period, which usually lasted 5 min. A lipase unit, derived from the use of this technique, may be defined as the number of microequivalents of acid liberated per minute under the specified conditions. The method was sensitive to 0.01 units. Various organisms tested produced 0.17 to 1.32 units per ml of the cell filtrate. An Arrhenius plot for staphylococcal lipase yielded 14,500 cal for function A (energy of activation).
Automated Turbidimetric Bioassay Readout Instrument Using a Multiple Flow-Cell System
Authors: Tsuji Kiyoshi , Griffith D. A. , Sperry C. C.
Published: December 2020

An instrument has been developed which permits the automatic quantitation of the turbidities of microbiological assay samples. Assay tubes were fed to the instrument at the end of the incubation period. The turbidity readings were automatically converted to digital data which were printed on International Business Machines (IBM) cards and from which potencies were calculated by an IBM computer. The instrument operated at a speed of over 240 tube readings per hour and was totally automatic in sample-mixing, readout, and data recording. The instrument is being used routinely at The Upjohn Co. for the turbidimetric bioassay of vitamins, with a coefficient of variation among repeated turbidity readings of 0.12 to 0.23%.
Stability and Effects of Some Pesticides in Soil
Authors: Bartha Richard , Lanzilotta R. P. , Pramer David
Published: December 2020

The influence of 29 pesticides on CO
2
production and nitrification by soil microorganisms was determined. A few compounds were stable but without significant effect in soil (chlorinated hydrocarbons), some persisted and depressed respiration and nitrification (carbamates, cyclodienes, phenylureas, thiolcarbamates), and others displayed toxicity but were transformed by soil microorganisms (amides, anilides, organophosphates, phenylcarbamates, triazines). Some compounds of the last type induced an initial increase and subsequent decrease in CO
2
production by soil. No simple explanation of this effect is possible, but the results of studies of model systems having established activities suggest that in soil any one or a combination of the following mechanisms is responsible for the observed complex relation of CO
2
production to time: (i) a pesticide acts to uncouple oxidative phosphorylation in a manner analogous to 2,4-dinitrophenol; (ii) a pesticide lacking antimicrobial action is oxidized in part and transformed to a stable and toxic product; (iii) a pesticide that is selectively toxic inhibits CO
2
production by sensitive microorganisms but is subject to oxidation without detoxification by other members of the microbial population that are resistant to its initial action. Pesticide concentrations greatly in excess of those recommended for agricultural and home use were required to produce an effect, and supplementary organic matter (glucose) tended to reduce pesticide toxicity and increase the microbial degradation of pesticides in soil.
Effects of Amphotericin B In Vitro on Perfect and Imperfect Strains of
Allescheria boydii
Authors: Nielsen H. S.
Published: December 2020

The inhibitory effects of amphotericin B on
Allescheria boydii
vary with the strain studied. In general, most isolates of the fungus are not susceptible to concentrations within the range of human tolerance. This is particularly true of perfect forms, although this relationship is lacking for some isolates. There is no correlation between the isolation history of a strain and its amphotericin B sensitivity. Susceptibility was found to be absolute in some isolates, whereas resistance could be increased in others through repeated exposure to higher increments of drug. In high concentrations, the antibiotic is uniformly cidal for the spores of certain isolates. This finding was also true for some conidia of “resistant” strains, although the action was fungistatic on other spores in the same population.
Chemically Characterized Media for Study of Foot-and-Mouth Disease Virus in Baby Hamster Kidney Cells
Authors: Polatnick Jerome
Published: December 2020

Foot-and-mouth disease virus can be grown in baby hamster kidney cells with a chemically characterized medium containing only tris(hydroxymethyl)-amino-methane (Tris) buffer, glucose, glutamine, and salts. Virus infectivity was only 0.5 log unit less than in a complex cell growth medium containing serum, tryptose phosphate, and lactalbumin hydrolysate. At high multiplicity of infection, production was maximal in 5 hr, with the virus remaining largely intracellular. Glucose and glutamine appeared to act independently of each other although both were required at about the same time during the virus production cycle. Glutamine had the greater effect and could not be replaced by amino acids, purines, and pyrimidines. Glutamine also stimulated cellular oxygen uptake in both normal and infected cells. Serum and other organic components added singly to the defined medium did not increase the virus yield. Studies on uninfected cells over a 5-hr incubation period showed that the defined medium maintained protein and ribonucleic acid synthesis at rates similar to the complex cell growth medium. These rates were much lower in media containing only inorganic salts and Tris buffer. Glucose, however, was more important to uninfected cellular metabolism than was glutamine. Defined medium containing dialyzed calf serum produced the highest rate of protein synthesis.
Use of Formalinized
Mycoplasma gallisepticum
Antigens and Chicken Erythrocytes in Hemagglutination and Hemagglutination-Inhibition Studies
Authors: Adler H. E. , Da Massa A. J.
Published: December 2020

Antigens were prepared from
Mycoplasma gallisepticum
in the logarithmic phase of growth and were treated with 2, 5, and 10% Formalin by slow diffusion through a dialysis sac. Chicken erythrocytes were similarly treated with 20% Formalin. Formalin-treated antigens hemagglutinated fresh and formalinized chicken erythrocytes. The antigens retained this hemagglutinating ability over an extended period.
Thermal Inactivation of Type E Botulinum Toxin
Authors: Licciardello Joseph J. , Nickerson John T. R. , Ribich Crystal A. , Goldblith Samuel A.
Published: December 2020

The theoretical required cooking times for inactivation of type E
Clostridium botulinum
toxin (5,000
ld
50
mouse units per 0.5 ml) in haddock fillets of various sizes were calculated by graphical integration of the toxin inactivation rate and heat penetration data. The results indicated that normal cooking procedures should suffice to inactivate this amount of toxin. This conclusion was substantiated by the following additional experimental observations which revealed that the original experiments had been conducted under conservative conditions. First, maximal heat stability of the toxin was found to occur at about
p
H 5.5, with decreasing resistance upon increasing
p
H. The theoretical cooking times were based on destruction of the toxin at
p
H 6.7. The
p
H of radio-pasteurized inoculated haddock, when toxin production had occurred, was on the alkaline side, at which condition the toxin is heat-labile. Second, when spoilage was discernible in radio-pasteurized inoculated haddock, the toxin titer was low, about 50
ld
50
mouse units per 0.5 ml. Third, the toxin was adequately inactivated in toxic fillets after deep-fat frying for 3 min at 375 F (190.6 C) or after pan frying for 5 min per side at 400 F (204.4 C). Fourth, in this study, residual toxin activity was assayed by intraperitoneal injection of mice. It was shown that the oral toxic dose was 50 to 100 times greater than the intraperitoneal toxic dose.
Recovery Patterns of Spores of Putrefactive Anaerobe 3679 in Various Subculture Media after Heat Treatment
Authors: Augustin Jorg A. L. , Pflug I. J.
Published: December 2020

A comparative study was made of the heat resistance of spores of putrefactive anaerobe 3679 grown in two different sporulation media and of the recovery pattern of these spores in several subculturing media after treatment with moist and dry heat. The heat resistance of the spores was characterized in the form of
D
and
z
values. The
D
values were determined by the modified Schmidt method. The
z
values were established by the graphic method. The results revealed significant differences in
D
and
z
values, depending on the type of heat and sporulation and subculture media. Spores grown in beef heart infusion showed higher heat resistance than those grown in Trypticase. Among the seven subculture media used, the largest number of spores was recovered in beef infusion. The magnitude of the
D
values at 121.1 C obtained with spores heated in moist heat decreased, depending on the subculture medium used, in the following order: beef infusion, pea infusion, yeast extract, liver infusion, Eugonbroth, Trypticase, synthetic medium. With spores subjected to dry heat,
D
values at 148.9 C decreased with the subculture medium in the following order: beef infusion, yeast extract, pea infusion and liver infusion, Trypticase, Eugonbroth, synthetic medium. The
z
values obtained with spores subjected to dry heat were approximately double those obtained with moist heat. Their relative magnitude varied slightly, depending on the type of subculture medium used. However, the relative magnitudes of the
D
values and
z
values with reference to the subculture media used were different with moist heat from those obtained with dry heat. Two theories are discussed as possible explanations for the logarithmic order of death of bacterial spores. The results obtained in these experiments, together with the findings of other workers, are most compatible with the theory that heat treatment of spores results in an increased rate of random injury to the genetic material of the spores.
Permeability of Oral Tissues to Blood-borne Coxsackievirus B-1
Authors: Madonia John V. , Bahn Arthur N.
Published: December 2020

The ability of coxsackievirus B-1 to pass the barriers of the circulatory system into whole saliva has been shown previously. In this investigation, the major salivary glands and the oral mucosa were studied, and their role as participants in the excretion of coxsackievirus B-1 during viremia was evaluated. The effect of the salivary-gland stimulant pilocarpine nitrate on both the salivary flow rate and the recovery of virus during viremia was determined. A comparison was made between the amount of virus recovered from whole saliva during viremia in animals deficient in one or both of the major salivary-gland pairs and animals with a complete complement of salivary glands. The salivary glands in other animals were cannulated, and pure glandular secretions were collected during viremia and assayed for the presence of virus The amount of virus passing from the capillaries of the oral mucosa to the surface was also determined to evaluate this route as a possible site for the excretion of virus into saliva during viremia. The major salivary glands did not excrete appreciable quantities of virus during viremia. The submaxillary-gland secretions did not contain virus, and the parotid-gland secretions showed virus only at extremely high blood virus levels. Either removal of the major salivary glands or decreased salivary flow rates increased the concentration of virus in whole saliva. This observation suggested that the production of saliva by the major salivary glands tends to dilute the virus in the oral cavity. A 0.88-cm
2
sample of the oral mucosa excreted significantly large amounts of virus during viremia and suggested that the passage of virus through the oral mucosa was the major route for the excretion of virus into saliva during viremia.
Effect of Herbicides on Cellulose Decomposition by
Sporocytophaga myxococcoides
Authors: Lembeck William J. , Colmer Arthur R.
Published: December 2020

The effects of 14 herbicides on cellulose decomposition by
Sporocytophaga myxococcoides
were studied by growing the organism in two different liquid cellulose-mineral salts media in the presence of the test agent and then quantitatively determining the residual cellulose. In the first medium, containing acid-hydrolyzed cellulose, anthrone reagent was used to determine residual carbohydrate. In the second medium, Gooch Pyrex fritted-glass crucibles were used to determine the amount of residual Whatman powdered cellulose. The herbicides used were Atrazine, Simazine, Dacthal, Diuron, Amiben, Banvel-D, Banvel-T,2,3,6-TBA, Dicryl, Maleic Hydrazide, Stam F-34, Zytron, Fenac, and Dalapon. Of these, Zytron appeared to be the most inhibitory to the test bacterium, and was the only compound exhibiting inhibition at a commonly used field rate of application (2 ppm).
Antibiotic Sensitivity of
Micrococcus radiodurans
Authors: Hawiger J. , Jeljaszewicz J.
Published: December 2020

A wild-type strain of
Micrococcus radiodurans
and its nonpigmented mutant W
1
were tested for sensitivity to 10 antibiotics selected from the standpoint of their mechanism of action. Representatives of groups of antibiotics inhibiting deoxyribonucleic acid (DNA) synthesis, DNA-dependent ribonucleic acid synthesis, protein synthesis, and cell wall synthesis were selected.
M. radiodurans
and its mutant exhibited full susceptibility to all antibiotics tested (mitomycin C, actinomycin D, chloramphenicol, dihydrostreptomycin, erythromycin, neomycin, kanamycin, benzylpenicillin, bacitracin, and vancomycin), the degree of susceptibility being of the same order as that of a standard strain of
Staphylococcus aureus
209 P, with the exception of dihydrostreptomycin.
Assessment of Virucidal Ability of Chemical Disinfectants
Authors: Grossgebauer Klaus
Published: December 2020

Increasing interest has been shown in studying and testing the virucidal properties of disinfectants. At the moment there are no well-established standard methods available; quite different procedures have been employed. Therefore, there is no satisfactory way of comparing the results obtained in this field. We present some of these problems and propose standard test methods to overcome these difficulties.
Fermentability of Corn Syrups with Different Dextrose Equivalents Added to Various Grape Juices
Authors: Steinkraus Keith H. , Robinson Willard B.
Published: December 2020

It was found that neither the enzymes of the grapes nor those of wine yeast
Saccharomyces ellipsoideus
strain 223 attacked the higher polysaccharides present in corn syrups. The alcohol yield of the corn syrups approached but did not quite reach theoretical assuming that all of the dextrose equivalent (DE) solids were fermented. Glucose, sucrose, and 95 DE corn syrup fermented at about the same rate and yielded comparable alcohol contents. At equal solids content, the 42 DE syrup fermented slower in most cases and yielded lower alcohol content than higher DE syrups.
Rapid Method for Measuring Extracellular Water in Yeast Preparations
Authors: Watson R. W. , Levinson M. L.
Published: December 2020

A rapid procedure for the quantitative determination of extracellular water in bulk bakers' yeast was developed on the basis of the solute dilution principle. A reagent is prepared by synthesizing the diazonium ion of
p
-aminobenzoic acid and coupling it to peptone. This “azopeptone reagent” permits direct colorimetric measurement, which accounts for the rapidity and simplicity of the test. Potential errors due to osmotic effects are avoided by supplementing the reagent with saline and, more importantly, minimizing the duration of contact between reagent and cells. The new method has acceptable accuracy and precision, and may also be suitable for use with other microorganisms.
Morphological and Biochemical Characteristics of
Aeromonas punctata
(
hydrophila, liquefaciens
) Isolated from Human Sources
Authors: Gilardi Gerald L.
Published: December 2020

The isolation of
Aeromonas punctata
(
hydrophila, liquefaciens
) from feces, throat, and sputum cultures is presented as further evidence that aeromonads are found in man. Morphological and biochemical studies of these strains indicate that the chief differences between the aeromonads and physiologically similar members of the
Enterobacteriaceae
are found in the polar arrangement of the flagella and in the production of oxidase by the former. The oxidase test should be performed on all paracolon-like bacteria, and a flagella stain should be employed when an oxidase-positive, gram-negative bacillus is isolated. Application of these tests will undoubtedly result in more frequent identification of
Aeromonas
species from human sources.
Examination of Prepared Foods in Plastic Packages for
Clostridium botulinum
Authors: Taclindo C. , Midura T. , Nygaard G. S. , Bodily H. L.
Published: December 2020

The incidence of
Clostridium botulinum
organisms was determined in a variety of plastic-packaged “vulnerable” foods (food requiring little or no heating prior to consumption). A total of 113 foods were examined by use of an enrichment recovery procedure followed by toxin testing in animals. Results of the survey indicate that the incidence of
C. botulinum
organisms in these vulnerable foods is extremely low. The ability of inoculated food products to support growth and toxigenesis of
C. botulinum
type E was then tested. The 64 packaged foods were inoculated with type E spores and incubated anaerobically at 30 C for 11 days. A slurry of each food was prepared, smears for fluorescent-antibody testing were made, and animal tests were performed for toxin. If the animal tests were negative, enrichment cultures were prepared from the slurry and incubated at 30 C. On direct examination of the slurries for toxin, only samples of turkey roll and soybean cake supported growth and toxigenesis by
C. botulinum
type E. However, the enrichment culture method was able to induce growth and toxin production in 60 of the remaining 62 samples.
Coconut and
Salmonella
Infection
Authors: Schaffner Carl P. , Mosbach Klaus , Bibit Venuso C. , Watson Colin H.
Published: December 2020

Raw, unprocessed coconut supports the growth of salmonellae as well as that of other enteric bacteria, salmonellae being particularly resistant to subsequent desiccation. Original contamination is not due to carriers or to polluted water supplies, but to contact with bacteria-containing soils followed by dispersion via infected coconut milk and shells. Pasteurization of raw coconut meat in a water bath at 80 C for 8 to 10 min effectively killed such bacteria, did not injure the product, and provided a prophylactic method now widely used by the coconut industry.
Effect of Food Additives and Irradiation on Survival of
Salmonella
in Oysters
Authors: Shiflett Maureen A. , Lee J. S. , Sinnhuber R. O.
Published: December 2020

Salmonella typhimurium
and
S. enteritidis
were inoculated into blended oysters, both raw and autoclaved. The oysters were also treated with sodium benzoate (0.1%) or potassium sorbate (0.1%), and irradiated (0.1 Mrad). In both non-irradiated and irradiated samples, greater numbers of
Salmonella
were recovered after storage at 7 C in the presence of sodium benzoate or potassium sorbate. The results of the autoclaved samples and studies in buffer indicated that this effect was not due to the reduction of competition from the natural flora when the additives were present.
Importance of Galacturonic Acid in Controlling the Retting of Flax
Authors: Rosemberg J. A. , De França F. P.
Published: December 2020

The empirical test was compared with the determination of
p
H, total acidity, and galacturonic acid (GA) as methods for establishing the termination time of the retting process in flax. The GA dosage was the best method for determining the end point of this process by distinctly dividing the phases of retting and over-retting in the bacterial loosening of flax fiber. This end point is critical in the production of standard fibers for the weaving industry.
Factors Influencing the Effectiveness of Swimming Pool Bactericides
Authors: Fitzgerald G. P. , DerVartanian M. E.
Published: December 2020

Techniques for culturing, harvesting, and testing bacteria to evaluate bactericidal chemicals for swimming pools are described. Concentrations of 25, 50, and 100 mg of the chlorine stabilizer cyanuric acid per liter increased the time required for a 99% kill of
Streptococcus faecalis
by 0.5 mg of chlorine per liter at
p
H 7.4 and 20 C from less than 0.25 min without cyanuric acid to 4, 6, and 12 min, respectively. The effect of concentrations of ammonia nitrogen in the range found in swimming pools on the rate of kill of 0.5 mg of chlorine per liter and of chlorine plus cyanuric acid was tested. At concentrations of ammonia nitrogen greater than 0.05 mg per liter, faster rates of kill of
S. faecalis
were obtained with 100 mg of cyanuric acid per liter plus 0.5 mg of chlorine per liter than with 0.5 mg of chlorine per liter alone. When water samples from four swimming pools with low ammonia levels were used as test media, 0.5 mg of added chlorine per liter killed 99.9% of the added
S. faecalis
in less than 2 min, but water from a pool with a large number of children required 60 to 180 min of treatment.
Broad-Spectrum Antimicrobial Activity of a New Triazenoimidazole
Authors: Pittillo Robert F. , Hunt Dale E.
Published: December 2020

Methyl-5(or 4)-(3,3-dimethyl-1-triazeno)-imidazole-4(or 5)-carboxylate was shown to have in vitro antimicrobial activity against gram-positive and gram-negative bacteria, yeasts, filamentous fungi, and algae. Preliminary studies with mice, experimentally infected with
Staphylococcus aureus
, have shown that this new antimicrobial agent has in vivo chemotherapeutic activity comparable to that observed with penicillin.
Microbial Destruction by Low Concentrations of Hypochlorite and Iodophor Germicides in Alkaline and Acidified Water
Authors: Hays Helen , Elliker P. R. , Sandine W. E.
Published: December 2020

Hypochlorite and iodophor germicides were evaluated for their ability to destroy a variety of organisms at levels approximating those used for final sanitizing rinse for dairy and food equipment and beverage bottles (3 to 50 ppm). Test organisms included
Escherichia coli, Streptococcus lactis, Lactobacillus plantarum, Pediococcus cerevisiae
, and
Saccharomyces cerevisiae
. The hypochlorites and iodophors demonstrated approximate rates of destruction at equivalent concentrations for the bacterial species tested, except where the hypochlorite contained excess alkalinity. The hypochlorite responded more readily to a downward shift to a
p
H of 5.0 than did the iodophor. Excess alkalinity of the hypochlorite significantly affected its bactericidal activity. The iodophor exhibited a consistently greater rate of destruction of yeast cells than the hypochlorite. Successive treatment with low levels of iodophor (6 ppm) followed by a hypochlorite (12 to 25 ppm) resulted in a high level of destruction of all test organisms. Possibilities for employing these measures in a sanitizing rinse of bottles for maximal destruction of organisms were discussed. Among the test organisms,
S. lactis
showed a comparatively high resistance and was a useful organism for comparing the halogen preparations.
Purification of the Moloney and Rauscher Murine Leukemia Viruses by Use of Zonal Ultracentrifuge Systems
Authors: Toplin I.
Published: December 2020

The B-IV and B-IX zonal ultracentrifuge rotors were applied to the concentration and purification of the Moloney and Rauscher murine leukemia viruses from large volumes of infected tissue culture fluids and animal materials. Potassium tartrate, potassium citrate and sucrose gradients were used to obtain viral concentrates from the density 1.16 to 1.18 zone. Proteolytic enzyme digestion of tissue culture preparations prior to zonal ultracentrifuge processing was effective in releasing virus from cell debris and producing highly purified, though nonleukemogenic, viral concentrates. Infected Rauscher mouse plasma was processed to give highly purified infectious virus fractions. A single centrifugation of crude Rauscher mouse spleen homogenates resulted in partially purified infectious concentrates with high virus particle counts.
γ Irradiation of Staphylococcal Enterotoxin B
Authors: Read R. B. , Bradshaw J. G.
Published: December 2020

The inactivation of enterotoxin B by γ irradiation was studied by use of single-and double-gel-diffusion assay techniques. Enterotoxin B (99+% purity) was suspended either in 0.04
m
Veronal buffer (
p
H 7.2) or in milk, dispensed and heat-sealed in borosilicate glass vials, and irradiated essentially at 21 to 26 C with a cobalt-60 source. Parallel titrations of irradiated enterotoxin B in Veronal buffer were made by use of gel-diffusion and cat assay procedures to establish the relative sensitivity of these two assay procedures to irradiated enterotoxin. Results were identical. A dose of 5 Mrad was required to reduce an enterotoxin B concentration of 31 μg/ml in Veronal buffer to less than 0.7 μg/ml. When milk was used as a vehicle, a dose of 20 Mrad was needed to inactivate a 30 μg/ml concentration of enterotoxin B to less than 0.5 μg/ml. With Veronal buffer and milk as vehicles, the
D
values (dose required to inactivate 90%) for enterotoxin B inactivation were 2.7 and 9.7 Mrad, respectively.