bluuebunny/crossref_metadata_2025 huggingface dataset:
Production and Evaluation of a Purified Adenovirus Group-Specific (Hexon) Antigen for Use in the Diagnostic Complement Fixation Test
Authors: Dowdle W. R. , Lambriex M. , Hierholzer J. C.
Published: December 2020

A simple procedure for the production of large volumes of purified adenovirus group-specific complement-fixing (CF) (hexon) antigen by selective adsorption to and elution from CaHPO
4
is described. Results of immunodiffusion tests, electrophoresis, electron microscopy, and tests for hemagglutination and infectivity indicate that the purified antigen consisted of a single virus component (hexon). The purified product contained little host materials. Unlike the crude virus harvest usually employed for serodiagnostic CF tests, the purified antigen demonstrated no anticomplementary activity and did not develop such activity during storage. The purified antigen was equal to or slightly more sensitive than crude virus harvests for serodiagnosis of adenovirus infections.
Prophage Induction in Lysogenic
Escherichia coli
with Simple Hydroxylamine and Hydrazine Compounds
Authors: Heinemann Bernard
Published: December 2020

The prophage-inducing capability of hydroxylamine sulfate and 36 of its derivatives, and of hydrazine dihydrochloride and dihydrazine sulfate and 43 of their derivatives, was determined in
Escherichia coli
W1709 (λ). Maximal nontoxic concentrations up to 1 mg/ml were tested. Hydroxylamine sulfate was active at 2.5 μg/ml and the following 17 derivatives were active at concentrations ranging up to 500 μg/ml: α-naphthylhydroxylamine,
N
-hydroxy-2-aminofluorene, oxamyl hydroxamic acid,
O
-carbamoyl hydroxylamine (isohydroxyurea),
N
-hydroxyurethane,
N
-methylhydroxylamine HCl, salicylhydroxamic acid, oxalohydroxamic acid, methoxyamine HCl, ethoxyamine HCl,
N, N
-diethylhydroxylamine oxalate, formaldoxime, formamidoxime, acetohydroxamic acid, acetaldoxime, acetone oxime, and hydroxyguanidine sulfate. Hydrazine dihydrochloride and dihydrazine sulfate were effective inducers at 5.0 and 2.5 μg/ml, respectively, and the following nine derivatives of them were active at concentrations ranging up to 500 μg/ml: phthalic acid hydrazide, phenylhydrazine HCl,
p
-nitrophenylhydrazine,
p
-chlorophenylhydrazine HCl, formylhydrazine, carbohydrazide, semicarbazide HCl, 1-methyl-1-phenyl-hydrazine sulfate, and acetic acid hydrazide. Nineteen hydroxylamine and 34 hydrazine derivatives were ineffective as inducers. Application of the prophage-induction system as a tool for detection of responsive hydroxylamino and hydrazino compounds which may be potential toxicological hazards in the environment is discussed.
T-2 Toxin Production by
Fusarium tricinctum
on Solid Substrate
Authors: Burmeister H. R.
Published: December 2020

A method has been developed to produce and purify gram quantities of T-2 toxin [4β, 15-diacetoxy-8α-(3-methylbutyryloxy)-12, 13-epoxytrichothec-9-en-3α-ol], a mycotoxin elaborated by a strain of
Fusarium tricinctum
isolated from toxic corn. After growing for 3 weeks at 15 C on 1,200 g of white corn grits,
F. tricinctum
NRRL 3299 elaborated at least 9.0 g of T-2 toxin, and 2.3 g of crystalline product was recovered. A lesser amount of toxin was produced on rice, but none was detected in wheat incubated at 20 C. The amount of toxin measured in white corn grits declined as the incubation temperature was raised to 20, 25, and 32 C.
Use of a New Buffer System with Formalinized Sheep Erythrocytes in the Rubella Hemagglutination-Inhibition Test
Authors: Gupta J. D. , Peterson V. J.
Published: December 2020

The increased sensitivity and improved agglutination and settling patterns of formalinized sheep erythrocytes in a new buffer, HEPES (
N
-2-hydroxyethylpiperazine
N
′-2′-ethanesulfonic acid), make this system more suitable for use in the rubella hemagglutination-inhibition test.
Ultrafiltration as a Method for Concentrating Rift Valley Fever Virus Grown in Tissue Culture
Authors: Klein Frederick , Mahlandt Bill G. , Bonner Hobert B. , Lincoln Ralph E.
Published: December 2020

Filtration by means of a Diaflo ultrafilter was used to concentrate three 1,000-ml lots and one 3,000-ml lot of tissue culture-grown Rift Valley fever virus. Quantitation of both infectivity and total protein was achieved. Water treatment with continued ultrafiltration of the virus concentrate provided a final virus product approximately 99.25% free of low-molecular-weight materials originally present in the growth medium.
Automated Method for the Determination of Phenol in Biological Products
Authors: Pemberton John R.
Published: December 2020

A method is described for the rapid and accurate determination of phenol in biological products by using automated methods.
Mobile Anaerobe Laboratory
Authors: Fulghum Robert S.
Published: December 2020

A laboratory cart equipped for obtaining clinical samples at bedside or operatory and for inoculating prereduced media for cultivation of medically important anaerobes is described.
New Method for Evaluating Antibacterial Activity Directly on Fabric
Authors: Lashen E. S.
Published: December 2020

Bacteriostasis of treated fabric was evaluated directly by a colony count made on the treated fabric after impregnation with seeded agar containing triphenyltetrazolium chloride and incubation in a horizontal, suspended position in a petri dish.
Preliminary Report of a New System for Typing
Salmonella typhimurium
in the United States
Authors: Wilson Virginia R. , Hermann George J. , Balows Albert
Published: December 2020

A new system is described for the bacteriophage typing of
Salmonella typhimurium
cultures isolated in the United States. The system is based upon one phage adapted to different
S. typhimurium
strains.
Lactic Acid Utilization by the Cutaneous
Micrococcaceae
Authors: Smith Rodney F.
Published: December 2020

Human cutaneous staphylococci and micrococci utilized lactic acid as an energy source on a minimal medium. Propionic acid was not utilized, but
l
(+)-lactic acid and pyruvic acid could replace
ld
-lactic acid as a substrate. Selected strains of cocci were inhibited more by the
l
(+) and
d
(−) forms of lactic acid than the balanced
ld
form, particularly at
p
H 5.6. With proper dilution of substrate, lactic acid was utilized by selected strains in the presence of 10 μg of oleic and palmitic acids per ml.
Some Factors Which Affect Amino Acid Uptake by
Saccharomyces carlsbergensis
Authors: Romkes S. C. E. , Lewis M. J.
Published: December 2020

When fully grown cells of
Saccharomyces carlsbergensis
were suspended in a solution of glucose and labeled amino acids, there was a lag phase before rapid uptake of certain amino acids. During this lag, significant amounts of sugar were utilized. The lag phase varied in length, depending upon the amino acid under study, but could be shortened by aeration of the cells and eliminated by their preincubation in glucose solution. Divalent metal ions, especially Ca
2+
added during the early stages of the lag phase, increased the length of the lag, an effect that could be reversed by washing with ethylenediaminetetraacetate, but amino acids which normally showed little or no lag before uptake were insensitive to Ca
2+
. The rate of uptake of amino acids or of sugar was essentially unaffected by Ca
2+
, whereas 2,4-dinitrophenol caused an overall decrease in the rate of uptake of all amino acids tested. The relevance of these observations to commercial brewing practice is shown.
Detection of Sulfa Drugs and Antibiotics in Milk
Authors: Read R. B. , Bradshaw J. G. , Swartzentruber A. A. , Brazis A. R.
Published: December 2020

A disc assay method for testing sulfa drugs and antibiotics in milk was developed wherein
Bacillus megaterium
ATCC 9855 was used as the test organism and Mueller-Hinton agar was used as the test substrate. Incubation was at 37 C for 4 to 5 hr. The test procedure is an improvement over the
Bacillus subtilis
-Antibiotic Medium No. 1 method, as described in
Standard Methods for the Examination of Dairy Products
, in that it is sensitive to eight sulfa drugs and to bacitracin without a significant change in sensitivity to eight other antibiotics commonly used for mastitis therapy.
Application of Immunofluorescence to Studies on the Ecology of
Sphaerophorus necrophorus
Authors: Garcia M. M. , Neil D. H. , McKay K. A.
Published: December 2020

Sphaerophorus necrophorus
(bovine liver abscess isolates) antiserum was fractionated and labeled with fluorescein isothiocyanate. The fluorescent-antibody (FA) conjugate proved to be species-specific and facilitated the detection of
S. necrophorus
cells in liver abscesses, viscera, and ruminal contents of cattle. Brightly fluorescing
S. necrophorus
cells were observed in experimentally inoculated soil incubated anaerobically at 37 and 4 C for 8 and 10 months, respectively. When incubated under moist conditions (80% water holding capacity) at 37 C, the test organism survived in both sterile and unsterile soil for as long as 8 weeks. Results strongly support the feasibility of using FA techniques concurrent with cultural methods for rapid detection of
S. necrophorus
infections.
Further Evaluation of the Automated Fluorescent Treponemal Antibody Test for Syphilis
Authors: Coffey E. M. , Naritomi L. S. , Ulfeldt M. V. , Bradford L. L. , Wood R. M.
Published: December 2020

Improvements in the equipment for the automated fluorescent treponemal antibody (AFTA) test for syphilis prompted this comparative study of the AFTA and its manual counterpart, the fluorescent treponemal antibody-absorption (FTA-ABS) test. The AFTA equipment operated satisfactorily, required only minimal monitoring, and afforded a three-to fourfold increase over the number of sera that could be tested manually by one serologist. The AFTA and FTA-ABS tests agreed well with only 2.1% of the sera yielding conflicting results. The AFTA was less precise than the FTA-ABS on sera retested because of original conflicting results and on sera retested within the same run to determine reproducibility. However, these differences were not large, and AFTA test performance was considered to be within the limits acceptable for a diagnostic serological procedure.
Dry-Heat Resistance of Bacterial Spores Recovered from Mariner-Mars 1969 Spacecraft
Authors: Wardle M. D. , Brewer W. A. , Peterson M. L.
Published: December 2020

The dry-heat resistances of 70 bacterial spore isolates recovered from Mariner-Mars 1969 spacecraft were determined and expressed as
D
values (decimal reduction times). Fifty per cent of the spore isolates had
D
values of 60 min or less at 125 C. Of organisms with
D
values greater than 60 min, four were selected for a study of the effect of sporulation medium and suspension menstruum on dry-heat resistance. Both sporulation medium and suspension menstruum were found to affect significantly the dry-heat resistance of the bacterial spores tested.
Relative Frequency Distribution of
D
125 C
Values for Spore Isolates from the Mariner-Mars 1969 Spacecraft
Authors: Bond W. W. , Favero M. S. , Petersen N. J. , Marshall J. H.
Published: December 2020

Bacterial spore crops were prepared from 103 randomly selected aerobic mesophilic isolates collected during a spore assay of Mariner-Mars 1969 spacecraft conducted by the Jet Propulsion Laboratory. D

125
c

values, which were determined by the fractional-replicate-unit-negative-most-probable number assay method using a forced air oven, ranged from less than 5 min to a maximum of 58 min. Subsequent identification of the 103 isolates indicated that there was no relationship between species and dry-heat resistance. A theoretical dry-heat survival curve of the “population” was nonlinear. The slope of this curve was determined almost exclusively by the more resistant organisms, although they represented only a small portion of the “population.”
Production of Substituted
l
-Tryptophans by Fermentation
Authors: Fukuda D. S. , Mabe J. A. , Brannon D. R.
Published: December 2020

Claviceps purpurea
has been shown to produce extracellular
l
-tryptophan from indole in stirred fermentors. The substrate specificity of this conversion was investigated by using substituted indoles, anthranilic acid, and 4-chloro-anthranilic acid. Addition of 2-, 4-, 5-, 6-, and 7-methyl indole or 6-chloroindole to
C. purpurea
C1M produced the corresponding substituted
l
-tryptophan. In contrast, addition of l-methyl, 6-trifluoromethyl, 6-nitro-, or 4-benzyloxy-substituted indoles, or anthranilic and 4-chloroanthranilic acids did not produce detectable amounts of the corresponding tryptophan.
Antibiotic Susceptibility Patterns of Recent Isolates of
Corynebacterium diphtheriae
Authors: McLaughlin Jane V. , Bickham Susan T. , Wiggins Geraldine L. , Larsen Sandra A. , Balows Albert , Jones Wallis L.
Published: December 2020

A variety of factors which might affect zone sizes were studied with strains of
Corynebacterium diphtheriae
; a standard disc method for antimicrobial sensitivity testing was used. Moderate variations in inoculum size, inoculum preparation, and
p
H of Mueller Hinton agar (MHA) did not appreciably affect zone sizes. The addition of blood to MHA was necessary to insure the growth of all
C. diphtheriae
strains on all lots of MHA. Zone diameters on MHA with blood were consistently 4 to 9 mm smaller than on plain MHA; however, zone diameters were within the sensitive range for seven antibiotic discs used on both media. Minimal inhibitory concentration (MIC) values for penicillin, erythromycin, and rifampin were determined by a plate dilution method. The geographical source, toxigenicity, and type of the strains showed no significant correlation with MIC values or zone diameters for eight antibiotic discs. When MIC values were compared to obtainable blood levels, all of the strains appeared to be sensitive with MIC values of ≤ 0.5 μg/ml for penicillin and ≤ 0.01 μg/ml for erythromycin and rifampin. Strains from persons who failed to have
C. diphtheriae
eliminated by one course of treatment with penicillin or erythromycin were examined. The susceptibility of these strains did not vary significantly from that of the other strains studied.
Microbiological Spoilage of Mayonnaise and Salad Dressings
Authors: Kurtzman C. P. , Rogers Ruth , Hesseltine C. W.
Published: December 2020

Saccharomyces bailii
was isolated from two-thirds of the spoiled mayonnaise and salad dressing samples examined. Most of the rest were spoiled by
Lactobacillus fructivorans
. However, one sample contained large numbers of both
S. bailii
and
L. plantarum
. Two of the spoiled samples also contained small numbers of bacilli.
Bacillus subtilis, B. pumilis, B. polymyxa, B. megaterium
, and
B. licheniformis
were found in one sample and
B. subtilis
and
B. pumilis
in another. Small numbers of
B. subtilis
and
B. licheniformis
were also present in one unspoiled sample. Several media were evaluated for the isolation of
L. fructivorans. S. bailii
and
L. fructivorans
vigorously fermented glucose. The concentration of glucose in the spoiled samples ranged from 0 to 38.5 g/kg and from 1.3 to 17.8 g/kg for the unspoiled samples.
Resistance to
d
-Cycloserine in the Tubercle Bacilli: Mutation Rate and Transport of Alanine in Parental Cells and Drug-Resistant Mutants
Authors: David Hugo L.
Published: December 2020

A single transport system was found to accumulate
l
- and
d
-alanine, glycine and
d
-serine in
Mycobacterium tuberculosis.
The results of inhibition experiments suggested that the antibiotics
d
-cycloserine and
O
-carbamyl-
d
-serine were also transported by the alanine-glycine-
d
-serine system. A
d
-cycloserine-resistant permease-competent (
d
-CS
r
/perm
+
) mutant and a
d
-cycloserine-resistant permease-defective (
d
-CS
r
/perm
−
) mutant were isolated. The
d
-CS
r
/perm
−
mutant was not found to be more resistant to the drug than was the
d
-CS
r
/perm
+
mutant. The data were consistent with the conclusion that resistance to
d
-cycloserine in the tubercle bacilli is primarily due to mutations in the gene(s) controlling the enzyme
d
-alanyl-
d
-alanine synthetase. The mutation rate was calculated to be about 10
−10
mutations per bacterium per generation.
Disc-Agar Diffusion Microbiological Assay Procedure for Determining Serum and Urine Levels of Sulfacytine and Other Sulfonamides
Authors: Heifetz Carl L. , Chodubski Josephine A. , DeCarlo Maureen O. , Fisher Myron W.
Published: December 2020

A reasonably precise, reproducible, and sensitive microbiological procedure for directly assaying sulfacytine and other sulfonamides as antibacterially active drugs has been developed by appropriately modifying the standard disc-agar diffusion technique. Blood and urine levels as low as 3 μg/ml may be determined through the use of a strain of
Escherichia coli
and a chemically defined agar medium devoid of sulfonamide antagonists. Results indicate that this assay method should be a useful adjunct to the Bratton-Marshall colorimetric procedure, by permitting the direct measurement of antibacterially active drug in clinical specimens.
Nonspecific Precipitation of Serum Proteins by Sodium Lauryl Sulfate in Agar Diffusion and Immunoelectrophoresis
Authors: Palmer E. L. , Martin M. L. , Hierholzer J. C. , Ziegler D. W.
Published: December 2020

The anionic detergent sodium lauryl sulfate (SLS), in a final concentration of 0.1% and greater, reacted with whole serum in agar diffusion and immunoelectrophoresis to form artifactual precipitin lines. These lines occurred when either Ionagar or agarose was used as the supporting gel and were not affected by the presence of urea and 2-mercaptoethanol. Analytic chemical tests confirmed that the precipitating agent is SLS, and staining techniques showed that the detergent precipitates both protein and lipoprotein components of whole serum. Multiple artifactual precipitin lines occurred with a wide variety of animal sera, and a single line formed with human 7
S
immunoglobulin. Hence, in agar diffusion studies in which SLS is present in the test system, these artifactual lines may be easily misinterpreted as true antigen-antibody precipitin reactions.
Comparison of Media for the Enumeration of
Clostridium perfringens
Authors: Harmon Stanley M. , Kautter Donald A. , Peeler James T.
Published: December 2020

For the enumeration of viable vegetative cells and spores of
Clostridium perfringens
, noncommercial (laboratory prepared) sulfite-polymyxin-sulfadiazine (SPS) agar, tryptone-sulfite-neomycin (TSN) agar, and Shahidi-Ferguson-perfringens (SFP) agar were statistically compared to SPS agar without antibiotics. The selectivities of these four media were also evaluated on the basis of their ability to inhibit the growth of pure cultures of a variety of other organisms. The average recovery of vegetative cells of 10 strains of
C. perfringens
with SFP agar was not significantly higher than with SPS agar with 10
4
organisms per g, but with 10
6
organisms per g it yielded significantly higher recoveries than SPS agar. TSN agar yielded significantly lower recoveries at both inoculum levels. SFP agar gave significantly higher recoveries of spores than SPS and TSN agars. Average plate counts of spores in SFP agar were 75% as high as in SPS agar without antibiotics, but only 45% of the spores grew in SPS agar and 25% in TSN agar. TSN agar was the most selective of the three media, but the selectivity of SPS agar approached that of TSN agar under the test conditions. SFP agar, which was the least selective of the media, allowed growth to some extent of nearly all of the facultative anaerobes tested.
Growth and Metabolism of L Cells in a Chemically Defined Medium in a Controlled Environment Culture System
Authors: Taylor G. W. , Kondig J. P. , Nagle S. C. , Higuchi K.
Published: December 2020

Six water-jacketed 500-ml Bellco spinner flasks were equipped to monitor and control environmental variables to study their effects on the growth and metabolism of mammalian cells. Studies with automated control of
p
O
2
levels of
l
-cell cultures, grown at
p
H 6.9 ± 0.1, showed that dissolved O
2
tensions of ca. 9% were optimal for cell growth. At
p
O
2
values of 5 and 20%, maximum cell yields as well as growth rates were reduced by approximately 20%. Peak yields of L-cell cultures exceeded 5 × 10
6
cells/ml when grown for 4 days without medium renewal from inocula of ca. 10
6
cells/ml in a defined medium sparged with 5% CO
2
and maintained at 9% dissolved O
2
tension. The redox potentials of L-cell cultures reflected the
p
O
2
levels in the medium and ranged from −45 to +160 mv (versus calomel reference) for O
2
values ranging from 2 to 20% dissolved oxygen tension. Increased utilization of glucose per cell occurred in the presence of increased
p
O
2
, whereas minimal accumulation of ammonia occurred with a
p
O
2
value maintained at 9%.
Assay System for Bacteriocins
Authors: Tagg J. R. , McGiven A. R.
Published: December 2020

Bacteriocin activity can be detected and assayed by a modification of the punchhole method.
Preliminary Observations on the Pathogenesis of a Virulent Strain of Newcastle Disease Virus in Chickens
Authors: Singh K. V. , Saad Najla , Zein A. El
Published: December 2020

Development of Newcastle disease, after experimental and natural infection with the virulent strain VLT of Newcastle disease virus, and its growth and distribution in some selected tissues as assayed by the enumeration of plaques are reported.
Adenosine Triphosphate Content of
Selenastrum capricornutum
Authors: Lee C. C. , Harris R. F. , Syers J. K. , Armstrong D. E.
Published: December 2020

The adenosine triphosphate content of
Selenastrum capricornutum
was maintained within 1.4 to 3.4 μg of adenosine triphosphate/mg (dry weight) of living biomass at different growth stages in media of different phosphorus concentrations.
Microbiological Assay and Tissue Distribution of 5-Diazouracil in Mice
Authors: Pittillo Robert F. , Woolley Carolyn
Published: December 2020

A sensitive, precise microbiological assay has been developed for the determination of tissue distribution of 5-diazouracil, a potential antitumor and antimicrobial agent.
Occurrence of
Vibrio parahaemolyticus
in Estuarine Waters and Oysters of New Hampshire
Authors: Bartley Clara H. , Slanetz L. W.
Published: December 2020

Vibrio parahaemolyticus
was isolated from water and oysters collected from seven different sampling stations in the Great Bay and Little Bay estuarine areas of New Hampshire. The morphological and biochemical characteristics of 50 isolates conformed in general to those described for this organism in the literature. All isolates produced hemolysis on blood-agar. To date, there have been no reports of
V. parahaemolyticus
food poisoning outbreaks due to the consumption of fish or shellfish harvested from this estuarine region.
Chemically Defined Medium for Growth of
Clostridium thermocellum
, a Cellulolytic Thermophilic Anaerobe
Authors: Fleming R. W. , Quinn L. Y.
Published: December 2020

Nutritional requirements of
Clostridium thermocellum
were examined, and a defined medium was formulated which supported reproducible growth through 10 serial subcultures.
Kinetics of the Vaccinia Virus Plaque Neutralization Test
Authors: O'Brien Thomas C. , Myers Martin G. , Tauraso Nicola M.
Published: December 2020

Neutralization of vaccinia virus with immune rabbit serum occurred optimally when incubated at 37 C for 16 to 24 hr in the plaque neutralization test employing the MA-104 embryonic rhesus monkey kidney cell line.
Accumulation and Elimination of Coliphage S-13 by the Hard Clam,
Mercenaria mercenaria
Authors: Canzonier Walter J.
Published: December 2020

Accumulation and elimination of viral particles by hard clams,
Mercenaria mercenaria
, were studied with the coliphage S-13 as a working model.
Escherichia coli
uptake and elimination were simultaneously monitored. Clams were exposed to low levels of S-13 (7 particles/ml) in running seawater for several days, achieving titers in tissues from 2 to more than 1,000 times the levels to which they had been exposed. Bacterial accumulation (previously established by other workers) was comparable. Upon exposure to virus-free running water, clams polluted to relatively low levels (100 plaque-forming units/ml) eliminated most of their bacterial contaminants in 24 to 48 hr. Viral contaminants, however, persisted for several days to weeks even under ideal conditions for clam activity, provided that the temperature remained below the inactivation threshold for the virus. Most of the accumulated virus appeared to be sequestered in the digestive gland. These sequestered particles are refractory to those mechanisms responsible for elimination of bacterial contaminants. This discrepancy points out the need for caution in evaluating the efficiency of shellfish depuration processes, especially if only a bacterial criterion is used as a monitoring system.
Resistance of
Pseudomonas
to Quaternary Ammonium Compounds
Authors: Adair Frank W. , Geftic Sam G. , Gelzer Justus
Published: December 2020

Tube dilution experiments showed that benzalkonium chloride (BC)-resistant mutants of
Pseudomonas aeruginosa
grown in the presence of 1,000 μg of BC per ml were at least 20 times more sensitive to polymyxin B and colistin sulfate than the BC-sensitive (BCS) parent strain. BCS cells selected for resistance to 500 μg of polymyxin B per ml remained sensitive to BC. There was little difference in the amount of carbenicillin, gentamicin sulfate, or rifampin needed to prevent growth of either the BCS or BC-resistant (BCR) strains. Growth of BCR cells was inhibited by ethylenediaminetetraacetate at a concentration of 400 μg/ml or less, whereas the BCS strain grew at ethylenediaminetetraacetate levels of 10,000 μg/ml. Phenylmercuric acetate and thimerosal inhibited growth of BCR and BCS cells at concentrations of 10 μg/ml or less. BCR cells were cross-resistant to >1,000 μg/ml concentrations of five other quaternary ammonium compounds, including three with C
16
alkyls and two with alkyl groups of shorter length. The BCS strain was also resistant to >1,000 μg/ml concentrations of the three quaternary ammonium compounds with C
16
alkyl groups but, in addition to BC, was inhibited by 200 μg/ml levels or less of the two quaternary ammonium compounds containing alkyl groups of less than 16 carbon atoms.
Effect of Toxin Concentration on the Heat Inactivation of Staphylococcal Enterotoxin A in Beef Bouillon and in Phosphate Buffer
Authors: Denny Cleve B. , Humber John Y. , Bohrer C. Wallace
Published: December 2020

The slope of the thermal inactivation curve of enterotoxin A in beef bouillon (initial
p
H 6.2) was found to be approximately 27.8 C (50 F) with three different concentrations of toxin. Inactivation by heat was dependent on the concentration of enterotoxin A heated. Enterotoxin A was inactivated by less heat in a
p
H 7.2 phosphate buffer than in beef bouillon as detected by serology. Results indicate that natural (usually low) levels of toxin rather than concentrated enterotoxin A should be used in heat inactivation studies.
Production of Anticapsin by
Streptomyces griseoplanus
Authors: Boeck L. D. , Christy K. L. , Shah R.
Published: December 2020

Anticapsin is a new fermentation product which inhibits formation of the hyaluronic acid capsule of
Streptococcus pyogenes
. Production of this metabolite in a complex medium by
S. griseoplanus
is enhanced by high levels of carbohydrate. A number of carbon sources support biosynthesis but sucrose is most effective, the optimum level being 150 g/liter. Neither glucose nor fructose, alone or in combination, serves as an equivalent substitute for sucrose. The addition of dibasic potassium phosphate to the medium further increases anticapsin production. Dissolved oxygen levels are important for synthesis and stability of the metabolite. Anticapsular activity diminishes rapidly in previously aerated broths which are held under static conditions. This decrease does not occur in pasteurized broths or unpasteurized filtrates.
Selective Mycobacteriophage Isolation with Membrane Filters
Authors: Grant J.
Published: December 2020

A simple technique is described whereby mycobacteriophages are selectively isolated by adsorption on mycobacteria layered within membrane filter sandwiches before standard enrichment procedures.
Modification of the Microtiter Reading Mirror for Use in the Standardized Micro Complement Fixation Test
Authors: Hui Gabriel W. K.
Published: December 2020

Modification of the Microtiter reading mirror used in the standardized diagnostic complement fixation method permits convenient estimation of the results in per cent hemolysis by direct visual comparison with the hemolytic standards.
Tremorgenic Toxins from Penicillia
Authors: Hou C. T. , Ciegler A. , Hesseltine C. W.
Published: December 2020

A low temperature (4 C) favors the accumulation of the mycotoxin tremortin when tremortin-producing molds are grown on various agricultural commodities. However, the rate of toxin formation is more rapid at a high temperature (20 C).
Practical Substitution for the Indole, Methyl Red, Voges-Proskauer, Citrate System
Authors: Von Graevenitz Alexander
Published: December 2020

A substitution for the indole, methyl red, Voges-Proskauer, citrate system is proposed. The scheme employs indole and ampicillin susceptibility tests routinely and uses selectively three other media for six reactions.
Failure of Urinary Beta-Glucuronidase Activity to Localize the Site of Urinary Tract Infection
Authors: Ronald Allan R. , Silverblatt Frederic , Clark Hugh , Cutler Ralph E. , Turck Marvin
Published: December 2020

The differentiation of renal from bladder bacteriuria is difficult on clinical grounds alone. To evaluate the correlation between site of infection and urinary beta-glucuronidase activity, 46 patients with well documented recurrent bacteriuria were studied by bilateral ureteral catheterization. Urinary beta-glucuronidase activity was also determined in 46 control subjects. In general, asymptomatic patients with renal bacteriuria, either unilateral or bilateral, had levels of enzyme activity in their urine comparable to patients with infection confined to the bladder and to normals. Only 4 of 25 patients with renal bacteriuria had significant elevations of urinary beta-glucuronidase. After localization of infection, 9 of 10 patients treated with kanamycin, a potentially nephrotoxic drug, developed significant elevations of urinary beta-glucuronidase. The results of these studies indicate that determination of beta-glucuronidase activity in urine is not useful in predicting the site of infection in patients with bacteriuria but may find a role in screening for early nephrotoxicity.
Effects of Citrate on the Composition and Metabolism of
Lactobacillus casei
Authors: Branen A. L. , Keenan T. W.
Published: December 2020

Lactobacillus casei
ATCC 393 converted small amounts of citrate to diacetyl, other volatile compounds, and lipids. Citrate was accumulated passively by the organism. The presence of citrate in the growth medium decreased the uptake of acetate and its conversion to cellular lipids. Cells grown in citrate media contained more protein per cell than did controls. This increased protein content was reflected mainly in the soluble fraction when cells were subjected to sonic lysis. Soluble fractions from cells cultured in the presence of citrate contained more total protein as well as more individual proteins than these fractions from control cells. The presence of citrate caused extensive flocculation and increased the susceptibility of cells to lysis.
“Upper Limits of Normal” Antistreptolysin O and Antideoxyribonuclease B Titers
Authors: Klein George C. , Baker Carolyn N. , Jones Wallis L.
Published: December 2020

“Upper limits of normal” antistreptolysin O (ASO) and antideoxyribonuclease (ADN) B titers were determined on serum specimens from various age groups of pediatric patients with no history of a recent streptococcal infection and on healthy adult hospital employees. The upper limit of normal value is that level of antibody titer exceeded by no more than 15% of the total subjects in each age group. This value varies with the age of the subject, and the most pronounced differences are between the values of preschool age children, school age children, and adults. The upper limit of normal values for these groups were as follows: preschool age, ASO = 85(100); ADN B = 60(50); school age, ASO = 170(166); ADN B=1 70(166); and adult, ASO = 85(100); ADN B = 85(100).
Improved Microscopy of
Mycoplasma
In Vitro
Authors: Hubbard John C. , Kite Joseph H.
Published: December 2020

Techniques were developed for continuous microscopic observation of mycoplasmata growing in vitro in Rose chambers by using an inverted phase microscope. The methods permitted direct microscopic observation of undisturbed growth of mycoplasmata in liquid medium. Inocula of mycoplasmata were passed through 0.22-μm filters before culture to provide a suspension of discrete particles. The sequential growth of
Mycoplasma pneumoniae
was followed from points or single straight lines, with development of branching, a net-like confluence of filaments, large bodies occurring in the center of developing colonies, and finally coccoid forms. Other species of
Mycoplasma
which did not attach as readily to glass could be observed also by inverted phase microscopy. Umbonation of colonies (a “friedegg” appearance) occurred in liquid medium, indicating that this appearance was not due simply to interaction with the agar medium, but may reflect a qualitative difference in growth patterns between center and periphery. For growth on solid medium, direct observation of colonies in uncovered plates of agar medium was made by using inverted phase microscopy. This was found helpful in detecting small colonies and in observing relationships between colonies.
Comparison of Two Plating Media for the Isolation of
Erysipelothrix rhusiopathiae
from Enrichment Broth Culture
Authors: Harrington Rube , Hulse D. C.
Published: December 2020

Sodium azide-crystal violet-agar and a modified blood-azide (MBA)-agar were used to isolate
Erysipelothrix rhusiopathiae
from swine tissues. There was no significant difference in the number of isolations. However, 78% of the isolants from modified blood-azide medium required only 24 hr of incubation, whereas all of the isolants obtained on sodium azide-crystal violet medium required 48 hr.
Growth of Human Lymphoid Cells (Raji Strain) in a Five-Liter Fermentor
Authors: Klein Frederick , Mahlandt Bill G. , Lincoln Ralph E.
Published: December 2020

Procedures used to produce an established line of mammalian cells (L cell) in a New Brunswick fermentor were adapted to propagate human lymphoid cells in suspended culture. Control of
p
H within defined limits was more effective for regulation of cell metabolism than control of oxidation-reduction potential. An unusually high rate of agitation was required.
Microtiter Tests for Detecting Antibody in Bovine Serum to Parainfluenza 3 Virus, Infectious Bovine Rhinotracheitis Virus, and Bovine Virus Diarrhea Virus
Authors: Rossi C. R. , Kiesel G. K.
Published: December 2020

Microneutralization tests for detection of antibody in bovine serum to three bovine viruses are described. The Madin-Darby bovine kidney cell line was used with parainfluenza 3 virus (PI 3), whereas serially cultivated bovine embryonic kidney cells were used for infectious bovine rhinotracheitis virus and bovine virus diarrhea virus. Comparison of micro-hemagglutination-inhibition (HI) with micro-serum-neutralization (SN) tests for PI 3 showed the SN test to be more sensitive, more specific, and therefore more useful than the HI test for detecting antibody. Although the effect of trypsin-periodate treatment of serum was to reduce the HI titer of numerous sera by a twofold dilution, sufficient evidence could not be found to indicate that nonspecific HI inhibitors to PI 3 are present in bovine sera.
Detection of Foot-and-Mouth Disease Virus Antibodies
Authors: Warrington R. E. , Kawakami Y.
Published: December 2020

Because 7
S
immunoglobulin (Ig) G antibodies of low type specificity were present in mixtures with highly specific 19
S
IgM antibodies, many bovine antisera to foot-and-mouth disease virus (FMDV) type A
12
, strain 119 cross-reacted with type O of FMDV and to some degree with type C in the passive hemagglutination (HA) test. After 19
S
IgM antibodies were separated by density gradient centrifugation or precipitated with 4% (w/v) polyethylene glycol, the antigen could be determined with “block” HA tests. Such tests used several antigen concentrations in the titration of each antiserum. Adding 4% (w/v) polyethylene glycol to the serum was especially convenient for rapid precipitation of 19
S
IgM antibodies for the test. Similar results were obtained with bovine 19
S
IgM antibodies to FMDV type O, subtype 1, strain Caseros and type C strain Rezende.
Inactivation of Thirty Viruses by Gamma Radiation
Authors: Sullivan Robert , Fassolitis Alexander C. , Larkin Edward P. , Read Ralston B. , Peeler James T.
Published: December 2020

Decimal reduction values (
D
value) for 30 viruses were determined. The weighted
D
values of the viruses suspended in Eagle's minimum essential medium ranged from 0.39 to 0.53 Mrads. It was necessary to increase the radiation dose by a factor of >3 to inactivate virus suspended in Eagle's minimum essential medium as compared to the same virus suspended in distilled water. The destruction rate curves were of a first-order reaction.
Quick Counting Method for Estimating the Number of Viable Microbes on Food and Food Processing Equipment
Authors: Winter F. H. , York G. K. , El-Nakhal Hamza
Published: December 2020

A rapid method for estimating the extent of microbial contamination on food and on food processing equipment is described. Microbial cells are rinsed from food or swab samples with sterile diluent and concentrated on the surface of membrane filters. The filters are incubated on a suitable bacteriological medium for 4 hr at 30 C, heated at 105 C for 5 min, and stained. The membranes are then dried at 60 C for 15 min, rendered transparent with immersion oil, and examined microscopically. Data obtained by the rapid method were compared with counts of the same samples determined by the standard plate count method. Over 60 comparisons resulted in a correlation coefficient of 0.906. Because the rapid technique can provide reliable microbiological count information in extremely short times, it can be a most useful tool in the routine evaluation of microbial contamination of food processing facilities and for some foods.
Cellulase Production by
Thermomonospora curvata
Isolated from Municipal Solid Waste Compost
Authors: Stutzenberger Fred J.
Published: December 2020

A cellulolytic, thermophilic actinomycete (previously isolated from municipal refuse compost samples) was identified as
Thermomonospora curvata.
A determination was made of the optimal conditions for cellulase production by
T. curvata
when grown at 55 C in a medium containing mineral salts, cellulose, and yeast extract. The
p
H and temperature optima (
p
H 6.0 and 65 C) for the cellulase produced by
T. curvata
were identical to those previously observed for the cellulase extracted from crude compost samples. Such similarities, together with the prevalence of
T. curvata
in compost samples and its ability to grow at composting temperatures, indicate that this actinomycete could possibly be considered as a major cellulose decomposer in the municipal refuse composting process.
Streptomyces torulosus
sp. n., an Unusual Knobby-Spored Taxon
Authors: Lyons A. J. , Pridham T. G.
Published: December 2020

Several strains of a streptomycete with unusual spore wall ornamentation were isolated from Iowa soils. They are further characterized by coiled chains of spores, gray aerial mycelium, melanin-like pigments, and the production of antibacterial and antifungal antibiotics. Spore wall ornamentations, as seen with the transmission electron microscope, do not correspond with any of the four generally recognized categories of spore wall ornamentation—smooth, warty, spiny, or hairy—but seem to represent an intermediate position between warty and spiny. This unusual ornamentation consists of blunt projections rising out of an otherwise smooth surface and is termed “knobby.” To obtain further information on the nature of the knoblike projections and their possible status in representing a defined spore wall ornamentation category, scanning electron micrographs and transmission electron micrographs representing all sporewall ornamentation categories were compared. Differentiation between the several categories was more difficult with the scanning electron microscope than with the transmission electron microscope.
Improved Solid Medium for the Detection and Enumeration of Pectolytic Bacteria
Authors: Hankin L. , Zucker M. , Sands D. C.
Published: December 2020

An improved solid agar medium (MP medium) has been developed which allows detection of pectolytic activity in bacteria. Organisms tested exhibited a variety of regulatory controls governing pectate lyase synthesis. The medium contains mineral salts, pectin, and yeast extract. After growth of the organisms, the agar plate is flooded with a polysaccharide precipitant, and pectolytic activity is shown by clear zones around active colonies. High concentrations of phosphate are shown to be necessary for pectic enzyme formation on solid media. The medium has successfully been used to detect pectolytic organisms in soil, forest litter, and rotting vegetable samples.
Analysis of Staphylococcal Enterotoxin B by the Polyacrylamide Electrophoresis Technique
Authors: Baier Harold L.
Published: December 2020

The electrophoretic mobility of enterotoxin B was investigated through the use of the disc electrophoresis technique. Ideal patterns were developed with a 7.5% acrylamide gel system (
p
H 4.3). The toxin can be separated and identified from other complex proteins such as serum or suspect samples of foods by this technique. The technique can be used as an assay method for the toxin as well as to elucidate physical changes in the toxin due to temperature. The method should not be considered exclusive for enterotoxin B.
Isolation of Psychrophilic Bacteriophage-Host Systems from Refrigerated Food Products
Authors: Whitman P. A. , Marshall R. T.
Published: December 2020

Thirty-eight bacteriophage-host systems were isolated from 22 of 45 refrigerated food products examined under psychrophilic conditions. Isolates were obtained from ground beef, pork sausage, chicken, raw skim milk, and oysters, whereas no isolations were made from liquid egg whites and processed meat products. Thirty of the 38 psychrophilic bacterial hosts were gram-negative rods, and 27 of these were classified within the genus
Pseudomonas
; three were members of the family
Enterobacteriaceae.
The remaining eight were gram-positive cocci, which were tentatively classified as
Leuconostoc.
Plate counts of psychrophilic bacteria were greater than 2.2 × 10
5
/ml (g) in all but one sample which contained phage, whereas phage titers ranged from less than 100 to 6.3 × 10
6
plaque-forming units/ml (g). Phage isolates showed limited host ranges usually attacking only those hosts upon which they were isolated. Of eight phages tested against 13 cultures of known identity, one showed lytic action, and this was against strains of
P. fragi.
Changes in
Escherichia coli
Associated with Acquired Tolerance for Quaternary Ammonium Compounds
Authors: Maxcy R. B. , Tiwari N. P. , Soprey P. R.
Published: December 2020

Acquired tolerance for a quaternary ammonium compound produced a tolerance for a similar compound. Tolerance was associated with the structure and the extent of adsorption of the compound. Morphological changes and resistance to disruption by pressure and by sonic treatment accompanied the development of tolerance. An otherwise weakened culture evolved with the acquisition of tolerance. The maximum obtainable viable population density of tolerant cells in growth medium was approximately 5% of that obtained in the parent culture. Tolerant cultures died off more rapidly in the original growth medium as well as when washed cell suspensions were stored at 5 C. Since acquired tolerance was associated with an otherwise weakened culture, the occurrence of the tolerant cells to limit the efficacy of quaternary ammonium compounds in sanitation operations is highly unlikely.
Regulation of Staphylococcal Enterotoxin B: Effect of Thiamine Starvation
Authors: Morse Stephen A. , Baldwin Jack N.
Published: December 2020

During the transition between the exponential and stationary phases of growth, there was a rapid accumulation of both cell-associated and extracellular enterotoxin B. Extracellular enterotoxin was synthesized until the cells entered the stationary phase during which cell-bound toxin was not detected. The differential rate of toxin synthesis relative to that of total protein synthesis was greater at
p
H 7.7 than at 6.0. Addition of glucose decreased the differential rate of toxin synthesis. This decrease was greater at
p
H 7.7 than at 6.0. Addition of pyruvate decreased the differential rate at
p
H 7.7 but not at 6.0. Analysis of the nongaseous end products of glucose and pyruvate metabolism showed that conditions which favor the oxidative decarboxylation of pyruvate also favor the repression of toxin synthesis. Elimination of thiamine from the medium prevented the oxidative decarboxylation of pyruvate by
Staphylococcus aureus
S-6 and partially or completely reversed the repression of toxin synthesis by glucose and pyruvate. In the absence of an added energy source, thiamine starvation caused a decrease in protein synthesis but an increased differential rate of toxin synthesis which was greater at
p
H 7.7 than at 6.0. In the absence of thiamine, pyruvate was not metabolized but caused a decrease in the rate of protein synthesis. This resulted in a twofold increase in the differential rate of toxin synthesis. Thus, conditions which altered the oxidative decarboxylation of pyruvate or decreased the rate of protein synthesis increased the rate of enterotoxin B synthesis.
Chemical Nature of Malty Flavor and Aroma Produced by
Streptococcus lactis
var.
maltigenes
Authors: Sheldon R. M. , Lindsay R. C. , Libbey L. M. , Morgan M. E.
Published: December 2020

Mature skim milk cultures of
Streptococcus lactis
var.
maltigenes
were steam distilled at low temperature under reduced pressure. Ethyl ether extracts were prepared from the distillates and analyzed by gas-liquid chromatography and mass spectrometry. Twenty of 31 components detected in the culture distillates were identified positively and 11 tentatively, whereas 10 of 19 components detected in the heated skim milk control were identified positively and 9 tentatively. Among components detected in the culture distillate, but not detected in the heated skim milk distillate, and which have not been previously identified in milk cultures of the organism were phenylacetaldehyde and phenethanol. Quantitative analyses of the volatiles entrained from milk cultures of several strains of
S. lactis
var.
maltigenes
revealed a probable relationship between variation in the character of the aroma of the cultures and the alcohol/aldehyde ratio.
Evaluation of Accuracy of Multitest Micromethod System for Identification of
Enterobacteriaceae
Authors: Washington John A. , Yu Pauline K. W. , Martin William Jeffery
Published: December 2020

The Analytab system of 20 biochemical tests for identification of
Enterobacteriaceae
was evaluated in parallel with conventional tests on 128
Enterobacteriaceae
, 5
Aeromonas
, and 1
Yersinia enterocolitica.
The results of tests for H
2
S and indole production, citrate utilization, lysine and ornithine decarboxylase, arginine dihydrolase, nitrate reduction, β-galactosidase, and fermentation of arabinose, rhamnose, mannitol, and glucose showed almost complete agreement between the two systems. Eighty-eight per cent of
Enterobacteriaceae
were correctly speciated with the Analytab system; on repeat testing with heavier inocula of organisms failing to ferment glucose initially, the proportion of
Enterobacteriaceae
correctly speciated became 93%.