bluuebunny/crossref_metadata_2025 huggingface dataset:
Validity of Spinal Cord Examination as a Substitute Procedure for Routine Rabies Diagnosis
Authors: Lee Tsun K. , Becker Maurice E.
Published: December 2020

A significant portion of specimens received by this laboratory for rabies diagnosis is unsatisfactory for testing due to decomposition of the brain, or severe mutilation of the head when the animal was killed. Examination of the spinal cord was therefore explored as a possible alternative method when standard brain examination was not possible. In this study, both brain and spinal cord of 248 rabies-suspect animals were examined to assess the reliability of the spinal cord method. Brain and spinal cord of the 248 animals were examined by fluorescent antibody (FA) method, and mouse inoculation tests were performed on 247 brain specimens and 13 spinal cord specimens. By using both brain and spinal cord, 30 animals representing 8 species were diagnosed as rabid by FA, and 218, representing 11 species, were negative. There was 100% agreement between two procedures with FA as the criterion. This study showed that in cases where the usual examination is precluded due to brain destruction, the spinal cord procedure offers an equally reliable alternate method of diagnosis.
Properties of Thymineless Strains of
Bacillus megaterium
Authors: Maisch W. F. , Wachsman J. T.
Published: December 2020

Both
Bacillus megaterium
KM:T
-
R
1
, a strain partially resistant to thymineless death, and strain KM:T
-
, the parent strain, can satisfy their thymine requirement with either thymidine, 5-methyldeoxycytidine, or 5-methyluridine. Neither strain can use 5-methylcytosine, 5-hydroxymethylcytosine, 5-hydroxymethyluracil, or 5-aminouracil for this purpose. Strain KM:T
-
R
1
requires as little as 0.01 mM thymine for maximum growth, whereas strain KM:T
-
requires 0.10 to 0.20 mM thymine. Lysogenic KM:T
-
R
1
dies more rapidly in the presence of mitomycin C than the corresponding phage-sensitive strain. Unexpectedly, the lysogenic strain was found to be less sensitive to thymineless death than the phage-sensitive strain. Lysogenic KM:T
-
R
1
is induced by exposure to mitomycin C and by thymineless incubation. It is concluded that thymineless death occurs by a mechanism which is unrelated to phage induction and that a major lethal effect of mitomycin C is probably a consequence of phage induction.
Identification of the Predominant Volatile Compounds Produced by
Aspergillus flavus
Authors: Kaminśki E. , Libbey L. M. , Stawicki S. , Wasowicz E.
Published: December 2020

A culture of
Aspergillus flavus
grown on moistened wheat meal was homogenized with a blendor, and the resulting slurry was vacuum-distilled at 5 mm of Hg and 35 C. The aqueous distillate was collected in traps cooled to -10 to -80 C. The culture volatiles were extracted from the distillate with CH
2
Cl
2
, and, after removal of the bulk of the solvent, the concentrated volatiles were examined by packed-column gas chromatography. Nineteen peaks were observed, and coupled gas chromatography-mass spectrometry was employed to identify the larger components. The compounds identified were: 3-methyl-butanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and
cis
-2-octen-1-ol. The two octenols were the predominant compounds, and sufficient sample was trapped from the gas chromatograph for infrared analyses; this confirmed the mass spectral identifications and permitted the assignment of the
cis
designation to 2-octen-1-ol. Both oct-1-en-3-ol and
cis
-2-octen-1-ol are thought to be responsible for the characteristic musty-fungal odor of certain fungi; the latter compound may be a useful chemical index of fungal growth.
Polysaccharide Produced by
Anacystis nidulans:
Its Ecological Implication
Authors: Sangar Vijay K. , Dugan Patrick R.
Published: December 2020

An extracellular polysaccharide from
Anacystis nidulans
was extracted from cell-free medium. Analysis showed that the polysaccharide consisted of glucose, galactose, and mannose in the ratio of 60:14:20. The production of polysaccharide depends on the age of culture, the growth temperature, and the form of nitrogen available.
Interferon Production by Human Cells In Vitro
Authors: Spina Celsa A. , Chang R. Shihman , Mishra L. , Golden H. Dean
Published: December 2020

The relative capacity of several types of human cells and tissue to produce interferon was studied. Types of cells and tissue included were fibroblasts from embryos, foreskins, and biopsied skins; amnion cells; peripheral leukocytes; established lymphoid cell lines; established heteroploid cell lines; and chorioamniotic membrane. When Newcastle disease virus was used as the inducer, fibroblasts and amnion cells produced more interferon per 10
6
cells than leukocytes, lymphoid cells, and heteroploid cells. Only minor variations in interferon-producing capacity were observed among fibroblasts from 36 persons. Culture passage level, cell concentration, and inducer were factors that significantly affected interferon production.
Simplified Radioimmunoassay for Diagnostic Serology
Authors: Hutchinson Harriet D. , Ziegler Donald W.
Published: December 2020

A simplified, indirect radioimmunoassay is described for
Escherichia coli
, vaccinia virus, and herpesvirus. The antigens were affixed to glass cover slips; thus both the primary and secondary reactions take place on the cover slips, and the unbound antiserum is easily separated from the bound antiserum by rinsing. Rabbit or human immune sera were reacted with the antigens, and the primary immune complex was quantitated by a secondary reaction with
125
I-indicator globulin (anti-rabbit or anti-human). A direct relationship between the antiserum concentration and the
125
I absorption was established. Variations in titers were detectable, and the titers were comparable to complement fixation titers. Homologous and heterologous reactions were distinguishable. The method affords an objective, quantitative, and qualitative evaluation of antibody, and results are reproducible.
Degradation of Chlorbromuron and Related Compounds by the Fungus
Rhizoctonia solani
Authors: Weinberger Martin , Bollag Jean-Marc
Published: December 2020

The ability of the soil fungus
Rhizoctonia solani
to degrade phenyl-substituted urea herbicides was investigated. The fungus was able to transform chlorbromuron [3-(3-chloro-4-bromophenyl)-1-methyl-1-methoxyurea] to the demethylated product [3-(3-chloro-4-bromophenyl)-1-methoxyurea], which was isolated and identified. Evidence was obtained that further degradation of chlorbromuron occurred. Several other phenylurea compounds (chloroxuron, diuron, fenuron, fluometuron, linuron, metobromuron, neburon, and siduron) were also metabolized by the fungus, indicating that
R. solani
may possess a generalized ability to attack this group of herbicides.

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Use of a Clonal Line of Porcine Kidney Cell Cultures for Primary Isolation and Vaccine Studies with Adenoviruses
Authors: Mogabgab William J. , Pollock Beatrice
Published: December 2020

The clonal line (Y15) of porcine kidney stable cells provided a recovery system for adenovirus T4 from specimens from adults with respiratory illnesses that was as sensitive as human embryo kidney cultures. Adenoviruses T7 from adults, and T1, 2, 3, and 5 from children could be readily isolated in porcine kidney cell cultures. The latter were useful for adenovirus vaccine studies in that infectivity titers of live virus vaccine and neutralization antibody responses after vaccination were equal to those obtained in human embryo kidney cultures.
Automatic Surface Inoculation of Agar Trays
Authors: Wilkins Judd R. , Mills Stacey M. , Boykin Elizabeth H.
Published: December 2020

A machine is described which automatically inoculates a plastic tray containing agar media with a culture by use of either a conventional inoculating loop or a cotton swab. Isolated colonies were obtained with an inoculating loop when a heavy inoculum (10
9
cells/ml) was used or with a cotton swab when a light inoculum (ca. 10
4
cells/ml) was used. Trays containing combinations of differential or selective media were used to (i) separate mixtures of gram-positive and gram-negative bacteria, (ii) facilitate isolation of organisms from clinical specimens, and (iii) compare colony growth characteristics of pure cultures. The design of the machine is simple, it is easy to use, and it relieves the operator from the manual task of streaking cultures.

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Pseudomonas putrefaciens
Isolates from Clinical Specimens
Authors: Riley P. S. , Tatum H. W. , Weaver R. E.
Published: December 2020

A total of 109 cultures of
Pseudomonas putrefaciens
isolated from clinical specimens were studied. The cultures were separated into two groups. The majority of the group 1 isolates, comprising 31 cultures, were characterized by (i) growth in plain nutrient broth, but no growth in broth supplemented with NaCl at concentrations of 7% and above, (ii) no growth on Salmonella-Shigella (SS) agar, and (iii) production of acid from the carbohydrates, sucrose, maltose, arabinose, and dextrin. Most group 2 isolates, comprising 78 cultures, were (i) unable to grow in plain nutrient broth, but grew well in broth supplemented with NaCl at a concentration of 7 to 10%, (ii) able to grow on SS agar, and (iii) unable to produce detectable amounts of acid from any of the carbohydrates tested except for variable results with glucose and fructose.
Quantitation of
Clostridium perfringens
Type A Enterotoxin by Electroimmunodiffusion
Authors: Duncan Charles L. , Somers Eileen B.
Published: December 2020

Conditions for quantitation of
Clostridium perfringens
type A enterotoxin by electroimmunodiffusion are described. As little as 0.01 μg of enterotoxin could be detected. Electroimmunodiffusion was more sensitive than either single gel diffusion or quantitation based on erythemal activity of the toxin in guinea pig skin.
Survival of Coliform Bacteria in Natural Waters: Field and Laboratory Studies with Membrane-Filter Chambers
Authors: McFeters Gordon A. , Stuart David G.
Published: December 2020

Chambers with membrane-filter side walls were designed for studies of the survival of coliform bacteria in natural and artificial waters. Experiments were carried out in the field and in the laboratory. The initial uptake rate of inorganic ions, total carbon, and glucose into the chamber was greater than twice as fast as the accumulation of each into dialysis tubing. When the survival of a water-isolated fecal coliform bacterium was examined in two adjacent mountain streams, it was found that the organism persisted longer in Bozeman Creek than in Middle Creek. These data may be a reflection of the water chemistry because the concentration of inorganic constituents of the former was greater. Laboratory studies of the survival of a fecal coliform bacterium in artificial and natural water with continuous flow were used to determine the effect of chemical composition, temperature, and
p
H. The relation of this type of data to the use of fecal coliform bacteria as indicators of health hazard in water is discussed.
Production of Diagnostic Pigment by Phenoloxidase Activity of
Cryptococcus neoformans
Authors: Shaw C. E. , Kapica L.
Published: December 2020

Cryptococcus neoformans
produces brown pigmented colonies when grown on agar media made from an extract of potatoes and carrots, broad beans (
Vicia faba
), or
Guizotia abyssinica
seeds. Since other yeasts do not produce the pigment, these media are useful as differential isolation media for
C. neoformans
. Similar specific pigment was produced by
C. neoformans
on chemically defined agar media which contained six different substrates of phenoloxidase (
o
-diphenol: oxygen oxidoreductase EC 1.10.3.1) an enzyme which catalyses the oxidation of
o
-diphenols to melanin. Substrates were incorporated singly into the media and included L-3, 4-dihydroxyphenylalanine (L-DOPA), chlorogenic acid, protocatechuic acid, catechol, norepinephrine, and 3-hydroxytyramine hydrochloride (dopamine). No pigment was produced on media without substrate. Phenoloxidase activity in (NH
4
)
2
SO
4
precipitates of
C. neoformans
cell-free extract was assayed by measuring increases in absorbance at 480 nm produced in solutions of L-DOPA. This reaction showed oxygen uptake and was effectively inhibited by copper chelators, but not by catalase. The enzyme also oxidized the five other substrates which induced pigment formation. Electron micrographs of cells incubated in L-DOPA showed deposition of the pigment in the cell wall.
pH-Dependent Polyol Production in Moniliella tomentosa
Authors: Hanssens L. , Van Regenmortel A. , Verachtert H.
Published: December 2020

Production of polyols by the yeastlike fungus
Moniliella tomentosa
could be increased by growing the organism at constant low
p
H. Up to 54% increase in yield was obtained. Growth at low
p
H also results in the production of D-arabitol which is not found in normal media.
Isolation of a New Soluble Antigen from the Yeast Phase of
Histoplasma capsulatum
Authors: Reeves Michael W. , Pine Leo , Kaufman Leo , McLaughlin David
Published: December 2020

A method is described by which a soluble antigen was prepared from the yeast phase of
Histoplasma capsulatum
. This soluble preparation had a specificity greater than that of whole-cell yeast-phase antigens. In complement fixation tests with sera from human cases of histoplasmosis, blastomycosis, and coccidioidomycosis, the soluble antigen reacted in 12.1% of 141 tests with heterologous sera, whereas conventional whole-cell yeast antigens reacted in 47.3% of 91 tests with heterologous sera. The reactivities of the two types of antigens with homologous sera were essentially the same.
Reliable Procedure for Silica Gel Preparation
Authors: Roslycky E. B.
Published: December 2020

A simple and reliable method is described for preparation of silica gel media for
Nitrosomonas
and
Nitrobacter
species.
Procedure and Analysis of a Useful Method in Determining Mycelial Dry Weights from Agar Plates
Authors: Sutton Lewis M. , Starzyk Marvin J.
Published: December 2020

The evaluation of growth by dry weight determination of fungus mycelium for agar plates was examined. The data obtained were statistically analyzed. This method was shown to be sufficiently accurate to be used as an investigative tool.
Effect of Extracts of the Bark of
Saccoglottis gabonensis
on the Microflora of Palm Wine
Authors: Faparusi S. I. , Bassir O.
Published: December 2020

Direct addition of the bark of
Saccoglottis gabonensis
to fresh palm juice followed by microbial enumeration every 6 hr showed that the bark inhibited bacterial growth appreciably. The effect of various extracts of the bark on two bacterial species isolated from palm wine (
Leuconostoc mesenteroides
and
Lactobacillus plantarum
) was studied by using the paper disc method. It was observed that three of the five constituents of the bark showed inhibitory effect on the bacteria.
Membrane Filter Technique for Enumeration of
Pseudomonas aeruginosa
Authors: Levin M. A. , Cabelli V. J.
Published: December 2020

A membrane filter procedure for the quantitation of
Pseudomonas aeruginosa
(mPA procedure) has been developed. Through the use of inhibitors and an elevated incubation temperature, the level of background microbial flora was decreased approximately 10,000-fold. Using
P. aeruginosa
cells suspended in sea water and held for 24 hr, between 70 and 100% of the “viable” cells could be recovered by the mPA procedure. Assay variability was found to be insignificant. The recoveries of
P. aeruginosa
from surface (fresh and salt) waters, potable waters, and sewage by the mPA procedure exceeded those obtainable by current methods. Subsequent to its development and evaluation, the mPA procedure was used at three other laboratories for the enumeration of
P. aeruginosa
in potable and recreational waters and in sewage samples. It was found amenable to routine use, and confirmation of typical colonies approached 100%.
Biodegradation of Ethylene Glycol by a Salt-Requiring Bacterium
Authors: Gonzalez Carlos F. , Taber Willard A. , Zeitoun M. A.
Published: December 2020

A gram-negative nonmotile rod which was capable of using
1,2
-
14
C
-ethylene glycol as a sole carbon source for growth was isolated from a brine pond, Great Salt Lake, Utah. The bacterium (ATCC 27042) required at least 0.85% NaCl for growth and, although the chloride ion was replaceable by sulfate ion, the sodium ion was not replaceable by potassium ion. The maximal concentration of salt tolerated for growth was approximately 12%. The bacterium was oxidase-negative when
N,N
-dimethyl-
p
-phenylenediamine was used and weakly positive when
N,N,N′,N′
-tetramethyl-
p
-phenylenediamine was used. It grows on many sugars but does not ferment them, it does not have an exogenous vitamin requirement, and it possesses a guanine plus cytosine ratio of 64.3%. Incorporation of ethylene glycol carbon into cell and respired CO
2
was quantitated by use of radioactive ethylene glycol and a force-aerated fermentor. Glucose suppressed ethylene glycol metabolism. Cells grown on ethylene and propylene glycol respired ethylene glycol in a Warburg respirometer more rapidly than cells grown on glucose. Spectrophotometric evidence was obtained for oxidation of glycolate to glyoxylate by a dialyzed cell extract.
Klebsiella
Biotypes Among Coliforms Isolated from Forest Environments and Farm Produce
Authors: Duncan D. W. , Razzell W. E.
Published: December 2020

Samples of water, soil, needles, and bark were collected from three different forest environments and from a pulp and paper mill. In addition, samples of fresh produce were obtained from a local supermarket. All samples were examined for total and fecal coliforms. The counts obtained from the forestrelated samples did not correlate with sample type or location. When 123 isolates were identified biochemically, 71% were
Klebsiella
, 19%
Enterobacter
, 8%
Citrobacter
, and 2%
Escherichia
. All the
Citrobacter
, 75% of the
Enterobacter
, and 65% of the
Klebsiella
were negative for growth in elevated coliform (EC) broth. All the
Escherichia
were EC positive. The counts obtained from the fresh produce were generally higher than the forest counts, but the distribution of biotypes was similar. Of the 146 isolates examined 64% were
Klebsiella
, 14% were
Escherichia
, 14% were
Enterobacter
, and 8% were
Citrobacter
. All the
Enterobacter
and
Citrobacter
were EC negative, whereas 25% of the
Klebesiella
and 80% of the
Escherichia
were EC positive.
Agar Medium for Differential Enumeration of Lactic Streptococci
Authors: Reddy M. S. , Vedamuthu E. R. , Washam C. J. , Reinbold G. W.
Published: December 2020

An agar medium containing arginine and calcium citrate as specific substrates, diffusible (K
2
HPO
4
) and undiffusible (CaCO
3
) buffer systems, and bromocresol purple as the
p
H indicator was developed to differentiate among lactic streptococci in pure and mixed cultures. Milk was added as the sole source of carbohydrate (lactose) and to provide growth-stimulating factors. Production of acid from lactose caused developing bacterial colonies to seem yellow. Subsequent arginine utilization by
Streptococcus lactis
and
S. diacetilactis
liberated ammonia, resulting in a localized
p
H shift back toward neutrality and a return of the original purple indicator hue. The effects of production of acid from lactose and ammonia were fixed around individual colonies by the buffering capacity of CaCO
3
. After 36 hr at 32 C in a candle oats jar, colonies of
S. cremoris
were yellow, whereas colonies of
S. lactis
and
S. diacetilactis
were white.
S. diacetilactis
, on further incubation, utilized suspended calcium citrate, and, after 6 days, the citrate-degrading colonies exhibited clear zoning against a turbid background, making them easily distinguishable from the colonies of the other two species. The medium proved suitable for quantitative differential enumeration when compared with another widely used general agar medium for lactic streptococci.
Associative Growth Studies in Three-Strain Mixtures of Lactic Streptococci
Authors: Reddy M. S. , Vedamuthu E. R. , Washam C. J. , Reinbold G. W.
Published: December 2020

A recently developed differential agar medium was used to study associative growth patterns in 17 different heterologous, three-strain mixtures of
Streptococcus lactis, S. cremoris
, and
S. diacetilactis
grown in milk. Mixtures were made by combining equal volumes of 18-hr milk cultures of the three species. Relative populations of component species were followed through three successive transfers in milk after the initial mixed propagation. Direct evidence for strain dominance and compatibility was obtained. A procedure also was developed to estimate the extent of suppression of
S. lactis
and
S. diacetilactis
in a mixture containing a dominant
S. cremoris
strain. The technique described could be successfully applied in quality-control work in the dairy-starter manufacturing industry.
Thermostable Acid Protease Produced by
Penicillium duponti
K1014, a True Thermophilic Fungus Newly Isolated from Compost
Authors: Hashimoto Hikotaka , Iwaasa Takashi , Yokotsuka Tamotsu
Published: December 2020

A thermophilic fungus, K1014, newly derived from a compost was selected on the basis of protease productivity as the only one of 81 isolates to produce high levels of acid protease. The fungus was named
Penicillium duponti
K1014 based on taxonomical studies. It grew in the temperature range of 28 to 58 C, and the optimum was 45 to 50 C. These temperature characteristics showed that the fungus was the most strongly thermophilic of all the fungi next to
Humicola lanuginosa
. When
P. duponti
K1014 was grown on moistened wheat bran, maximal accumulation of acid protease occurred after 2 days at 45 to 50 C. The addition of ammonium salts, but not nitrate, was effective for the production of the acid protease. The acid protease of
P. duponti
K1014 was stable at 60 C for 1 hr and retained more than 65% of original activity after the treatment for 1 hr at 70 C at
p
H 4.7. This thermal property was different from those of the ordinary acid proteases, indicating that the enzyme is a thermostable protein.
Induction of Protoplasts of
Schizosaccharomyces octosporus
in a Defined Medium
Authors: MacDonald Christine E. , Berliner Martha D.
Published: December 2020

Protoplasts of
Schizosaccharomyces octosporus
were formed in a defined medium consisting of yeast nitrogen base, adenine, glucose, MgSO
4
, and 2-deoxy-D-glucose.
Competitive Inhibition for Amino Acid Uptake by the Indigenous Microflora of Upper Klamath Lake
Authors: Burnison B. Kent , Morita Richard Y.
Published: December 2020

The uptake of a specific
14
C-amino acid by the heterotrophic microorganisms in the epilimnion of an eutrophic lake was influenced by the presence of other amino acids. The effect of unlabeled serine on
14
C-glycine uptake was shown to be caused by competitive inhibition, which changed the interpretation of the kinetic parameters, the turnover time,

T
t

, and the sum of a transport constant, (

K
t

+ (

S
n

), and the natural substrate concentration. The maximum velocity of uptake,
V
max
, is unaffected by the competitive inhibition.
A Rapid, Presumptive Procedure for the Detection of
Salmonella
in Foods and Food Ingredients
Authors: Hoben D. A. , Ashton D. H. , Peterson A. C.
Published: December 2020

A rapid detection procedure was developed in which a lysine-iron-cystine-neutral red (LICNR) broth medium, originally described by Hargrove et al. in 1971, was modified and used to detect the presence of viable
Salmonella
organisms in a variety of foods, food ingredients, and feed materials by using a two-step enrichment technique. Tetrathionate broth was used to enrich samples with incubation at 41 C for 20 hr, followed by transfer to LICNR broth and incubation at 37 C for 24 hr for further enrichment and for the detection of
Salmonella
organisms by color change. One hundred ten samples representing 18 different sample types were evaluated for the presence of viable
Salmonella
. Ninety-four percent of the samples found to be presumptive positive by this method were confirmed as positive by a culture method. Fluorescent-antibody results also compared closely. A second study was conducted under quality-control laboratory conditions by using procedures currently employed for
Salmonella
detection. One hundred forty-three samples representing 19 different sample types were evaluated for the presence of viable
Salmonella
. No false negatives were observed with the rapid-detection method. The usefulness of the LICNR broth procedure as a screening technique to eliminate negative samples rapidly and to identify presumptive positive samples for the presence of viable
Salmonella
organisms was established in this laboratory.
Effects of Homologous Bacteriophage on Growth of
Pseudomonas fragi
WY in Milk
Authors: Ellis D. E. , Whitman P. A. , Marshall R. T.
Published: December 2020

Pseudomonas fragi
strain WY and its homologous bacteriophage were added in varying concentrations to sterile skim milk which was stored at 7 C for 72 hr. When the initial concentration of the bacterial host was 100,000/ml, addition of as few as 10 plaque-forming units per ml of bacteriophage resulted in significantly lower counts in treated skim milk than in the controls which contained no phage. There was no significant effect, however, when the phage input was 1 in 10 ml and the bacterial count was 1,000 or 100,00/ml. No differences in bacterial counts occurred even when the phage concentration was 1,000/ml if the initial bacterial concentration was only 1,000/ml.
Determination of the Optimal Ammonium Sulfate Concentration for the Fractionation of Rabbit, Sheep, Horse, and Goat Antisera
Authors: Hebert G. Ann , Pelham Patricia L. , Pittman Bertie
Published: December 2020

Various ammonium sulfate concentrations and reaction conditions were employed in the fractionation of sera from rabbits, sheep, horses, and goats. Precipitates and supernatant fluids were analyzed by electrophoresis to study the effects of the controlled variables. At room temperature, the third precipitate in 35% saturated (NH
4
)
2
SO
4
was the best fraction from both rabbit and sheep sera; 80 to 90% of the gamma globulins were recovered. The second and third precipitates of horse sera proteins in 30% saturated (NH
4
)
2
SO
4
were both satisfactory, but only 44% of the gamma globulin was recovered after three precipitations. Goat sera yielded a very satisfactory fraction; 80% of the gamma globulin was recovered after two precipitations—the first in 30% and the second in 45% saturated (NH
4
)
2
SO
4
. The composition of these fractions was not influenced by the
p
H of the sulfate solutions (
p
H 5.8 and 7.2), by a range of normal room temperatures (20 to 30 C), or by diluting the sera before fractionation. Crude globulins and fluorescein isothiocyanate-labeled globulins were successfully refractionated by one precipitation in the optimal sulfate concentration for the appropriate animal species. The refractionated products contained considerably less beta and alpha globulins than did the original crude fractions and little or no albumin.
Three-Day Assay for Human Cytomegalovirus Applicable to Serum Neutralization Tests
Authors: Waner Joseph L. , Budnick Joan E.
Published: December 2020

A fluorescing cell assay (FCA) technique utilizing the indirect fluorescent-antibody method to measure human cytomegalovirus (CMV)-infected cells has been applied to the rapid determination of CMV-neutralizing antibody. Human sera with complement fixation titers to CMV of 1/32 or greater and fluorescein-conjugated rabbit anti-human globulin are the primary and secondary reagents in the fluorescent-antibody test. FCA measured in 3 days the same number of infectious units measured by plaque assay in 2 weeks. FCA and plaque assay yielded identical neutralizing antibody titers to CMV in 20 human sera.
Comparison of Methods for Isolation of Anaerobic Bacteria from Clinical Specimens
Authors: Rosenblatt Jon E. , Fallon Ann , Finegold Sydney M.
Published: December 2020

Five different anaerobic culture methods and several different media were compared for their ability to recover anaerobes from clinical specimens. Specimens were obtained from patients with documented infections, avoiding contamination with normal flora, and immediately placed in an anaerobic transporter. Each specimen was cultured by all methods and on all the various media. The comparative data indicate that anaerobic jars (GasPak and evacuation-replacement types) are just as effective in the recovery of clinically significant anaerobes as the more complex roll-tube and chamber methods employing prereduced media. Liquid media were disappointing as a “back-up” system but chopped-meat glucose was superior to two thioglycolate formulations. Growth of all anaerobes was poorer on selective media, but these media were very helpful in the workup of specimens containing mixed growth of anaerobic and facultative organisms. A variety of different anaerobes was isolated, but no very fastidious or extremely oxygen-sensitive organisms were recovered. This suggests that such organisms may not play a significant role in causing clinical infections.
Survival of Airborne Bacteria in a High Urban Concentration of Carbon Monoxide
Authors: Lighthart Bruce
Published: December 2020

Vegetative cells of
Serratia marcescens
8UK,
Sarcina lutea
, and spores of
Bacillus subtilus
var.
niger
were held in aerosols, with and without an urban concentration of CO (85 μliters per liter or ppm), for up to 6 hr at 15 C and a relative humidity (RH) of approximately 0, 25, 50, 75, and 95%. It was found that CO enhanced the death rate of
S. marcescens
8UK at least four- to sevenfold at low RH (ca. 1 to 25%), but protected the cells at high RH (ca. 90%). Death rates of
S. lutea
, with or without added CO, were comparatively low over the entire RH range. However, in the first hour, airborne
S. lutea
held in CO-containing air were more stable than those in air without added CO (i.e., CO protection). A marked increase in the death rate (up to 70-fold) occurred in the subsequent 5 hr within the RH range of approximately 0 to 75%. Statistical analysis indicated that aerosol decay rates of
B. subtilus
var.
niger
spores decreased significantly, when held in a CO-containing as compared to a non-CO-containing atmosphere, in the 0 to 85% RH range. Thus, the data presented indicate that CO in the urban environment may have a protective or lethal effect on airborne bacteria, dependent upon at least the microbial species, aerosol age, and relative humidity. A mechanism for CO death enhancement and protection of airborne
S. marcescens
8UK is suggested to involve CO uncoupling of an energy-requiring death mechanism and an energy-requiring maintenance mechanism at high and low RH, respectively.
Fermentation Kinetics and Continuous Process of L-Asparaginase Production
Authors: Liu F. S. , Zajic J. E.
Published: December 2020

For the purpose of obtaining L-asparaginase in quantities from
Erwinia aroideae
, cell growth and enzyme formation were investigated in both batch and continuous fermentation. Using yeast extract as a growth-limiting substrate, the relationship between specific growth rate and substrate concentration was found to fit the Monod equation. The optimum temperature for enzyme production was 24 C, although cell growth was higher at 28 C. The enzyme yield reached its maximum of 4 IU/ml during the negative acceleration growth phase which occurs just prior to stationary growth. Compared to batch fermentations, the continuous fermentation process gave a lower enzyme yield except when the fermentation was conducted at a dilution rate of 0.1 hr
-1
. The graphical method frequently used for prediction of continuous fermentation does not apply to L-asparaginase production by
E. aroideae
. The optimum temperature for enzyme production in continuous process was 24 C, which was the same as in batch process. Increasing the temperature from 24 to 28 C resulted in a 20% loss of enzyme yield.
Growth of
Hansenula holstii
on Cadavers
Authors: Kurtzman C. P. , Gentles J. C. , Evans E. G. V. , Slodki M. E. , Ward R. M.
Published: December 2020

Growth of a yeast was observed on prosected cadavers used for demonstration purposes in a medical school. An asporogenous yeast was isolated and identified as an atypical form of
Hansenula holstii
by analysis of the extracellular polysaccharide. The isolate showed resistance to embalming fluid but was eventually eradicated by addition of picloxidine digluconate to the fluid.
Applications of a Synthetic Neuraminidase Substrate
Authors: Palese P. , Bucher D. , Kilbourne E. D.
Published: December 2020

A rapid and precise assay for neuraminidase using 2-(3′-methoxyphenyl)-
N
-acetyl-α-neuraminic acid (MPN) is described. It is proposed that this substrate be used for the standardization of activity of neuraminidases from viral, bacterial, and mammalian sources. MPN is also used as a chromogenic substrate to localize influenza and parainfluenza virus foci in tissue culture. This technique permits the recovery of infective virus from these stained “plaques.” It has also been demonstrated that immunoprecipitin lines containing neuraminidase complexes with antibody in the Ouchterlony test can be observed by a similar staining procedure. No enzyme inhibition occurs in the presence of anti-neuraminidase antibodies or concanavalin A when MPN is used as a substrate in contrast to the results with high-molecular-weight substrates such as fetuin.
Halophilic Bacteria Susceptibility to Peracetic Acid Vapor and Ethylene Oxide
Authors: Tasch Paul , Todd Barbara
Published: December 2020

Extremely to slightly halophilic bacteria were tested for susceptibility to two sterilizing agents, peracetic acid (PAA) and ethylene oxide (ETO). PAA susceptibility was explored by two methods: an agar plate (constant
p
H of 7.2) and a filter strip (constant incubation period of 37 days); 100% susceptibility was obtained by both methods. The dosage (0.5 ml/min) was applied to a filter pad in a petri dish cover. Glove box experiments with ETO (input 1.5 lb. [ca. 680.4 g]/24 hr, the only constant) yielded 100% susceptibility for all halophiles tested. These experiments demonstrated the efficacy of two lethal agents for extreme halophiles, PAA and ETO. Variation in
p
H did not affect susceptibility.
Survivor Curves for
Leptospira autumnalis
Akiyami A Based on Most-Probable-Number Values
Authors: Schiemann D. A.
Published: December 2020

The validity of survivor curves for
Leptospira autumnalis
Akiyami A based on most-probable-number values is supported by the following observations: (i) linear regression lines fell within most of the 95% confidence intervals; (ii) linear correlation coefficients (
r
) were consistently high (i.e., near -1); and (iii) statistical tests for goodness of fit usually accepted the linear model. These tests are consistent with an exponential death rate for the test organism in defined solutions. The influence of temperature and
p
H on survival was demonstrated by showing a statistically significant difference in survivor curve slopes.
Volatile Compounds Produced in Sterile Fish Muscle (
Sebastes melanops
) by
Pseudomonas perolens
Authors: Miller A. , Scanlan R. A. , Lee J. S. , Libbey L. M. , Morgan M. E.
Published: December 2020

Volatile compounds produced by
Pseudomonas perolens
ATCC 10757 in sterile fish muscle (
Sebastes melanops
) were identified by combined gas-liquid chromatography and mass spectrometry. Compounds positively identified included methyl mercaptan, dimethyl disulfide, dimethyl trisulfide, 3-methyl-1-butanol, butanone, and 2-methoxy-3-isopropylpyrazine. Compounds tentatively identified included 1-penten-3-ol and 2-methoxy-3-sec-butylpyrazine. The substituted pyrazine derivative 2-methoxy-3-isopropylpyrazine was primarily responsible for the musty, potato-like odor produced by
P. perolens.
Rapid Method to Determine Labeling Specificity of Radioactive Enteroviruses
Authors: Herrmann John E. , Cliver D. O.
Published: December 2020

The specificity of labeling enteroviruses with
32
P-labeled NaH
2
PO
4
or
14
C-leucine can be determined by comparing the percent adsorption of infective particles and radioactivity to membrane (Millipore) filters.
Evaluation of Two Types of Infectious Mononucleosis Antigen Slides by the Indirect Fluorescent-Antibody Technique
Authors: Dye Leota A. , Feorino Paul M.
Published: December 2020

The efficiency of two types of antigen slides was compared by using the indirect fluorescent-antibody technique. Fifty sera from infectious mononucleosis patients were tested concurrently on the two sets of slides for antibody to Epstein-Barr virus. The indirect fluorescent-antibody serum titer readings from the epoxy slides were either equal to or twofold higher than those from the cover slip slides.
Bacterial Cleavage of an Arylglycerol-β-Aryl Ether Bond
Authors: Crawford R. L. , Kirk T. K. , Harkin J. M. , McCoy Elizabeth
Published: December 2020

The first known cleavage by a bacterium of an arylglycerol-β-aryl ether linkage, the most common intermonomer linkage in lignin, is described.
Production and Heat Stability of Staphylococcal Nuclease
Authors: Erickson Allan , Deibel R. H.
Published: December 2020

No correlation existed between numbers of organisms and nuclease activity in laboratory-grown cultures of
Staphylococcus aureus
. Nuclease production was inhibited by anaerobic incubation and stimulated by aeration. Strains of
S. aureus
varied in the production of nuclease. The optimum pH for enzyme production was 8.3 and employment of a tris(hydroxymethyl)aminomethane buffer system resulted in increased production of the enzyme as compared with a phosphate buffer. The nuclease was extremely heat-stable and had a D value of 16.6 min at 130 C.
Turbidimetric Assay of Staphylococcal Nuclease
Authors: Erickson Alan , Deibel R. H.
Published: December 2020

A simplified turbidimetric procedure was developed to assay staphylococcal nuclease activity. The ease of performance and sensitivity to nanogram quantities enhance the utilization of the method for the quantitative or qualitative estimation of the enzyme. Unlike plating methods, the turbidimetric procedure affords the differentiation between heat-stable and heat-labile nuclease activity.
Subcutaneous Bacteria in Turkey Carcasses
Authors: Avens John S. , Miller Byron F.
Published: December 2020

Two methods were employed to quantitate the subcutaneous bacteria in fresh, refrigerated, and frozen turkey carcasses. Relatively few bacteria were detected in the skin-flesh interface and in the flesh as compared with the number of bacteria on the skin surface and in the skin layer. No subcutaneous bacteria were detected in 49% of the skin-flesh interface and flesh samples. The number of bacteria detected in skin samples from carcasses chemically disinfected to kill skin surface bacteria was smaller than that in nondisinfected skin samples. These results indicate that the skin blending method used to quantify microorganisms on poultry carcass skin measures the skin layer flora and that the number of subcutaneous membrane or flesh bacteria measured is not normally large enough to have a significant influence on the results.
Delayed-Incubation Membrane-Filter Test for Fecal Coliforms
Authors: Taylor Raymond H. , Bordner Robert H. , Scarpino Pasquale V.
Published: December 2020

A delayed-incubation membrane-filter technique for fecal coliforms was developed and compared with the immediate fecal coliform test described in
Standard Methods for the Examination of Water and Wastewater
(13th ed., 1971). Laboratory and field evaluations demonstrated that the delayed-incubation test, with the use of the proposed vitamin-free Casitone holding medium, produces fecal coliform counts which very closely approximate those from the immediate test, regardless of the source or type of fresh-water sample. Limited testing indicated that the method is not as effective when used with saline waters. The delayed-incubation membrane-filter test will be especially useful in survey monitoring or emergency situations when the standard immediate fecal coliform test cannot be performed at or near the sample site or when time and temperature limitations for water sample storage cannot be met. The procedure can also be used for analyzing the bacterial quality of water or waste discharges by a standardized procedure in a central examining laboratory remote from the sample source.
Survival of Airborne
Pasteurella tularensis
at Different Atmospheric Temperatures
Authors: Ehrlich Richard , Miller Sol
Published: December 2020

The aerosol survival, recovery, and death rate of
Pasteurella tularensis
SCHU S5 disseminated in particle sizes of 1 to 5 μm were significantly affected by air temperature. The highest aerosol recovery of viable
P. tularensis
was observed within -7 and 3 C; the recovery decreased significantly below and above this temperature range. The death rate of airborne
P. tularensis
was not significantly influenced by an increase in temperature from -40 to 24 C. However, a progressive increase in atmospheric temperature from 24 to 35 C resulted in increased death rates; thus, a linear relationship appeared to be present between the temperature and death rates. At 49 C, the recoveries of viable airborne
P. tularensis
were significantly lower and the death rates were higher than at the other temperatures.
Biosynthesis of Prodigiosin, a Secondary Metabolite of
Serratia marcescens
Authors: Williams Robert P.
Published: December 2020

Prodigiosenes (prodigiosin and prodigiosin-like pigments) are known to be synthesized by only one genus of
Eubacteriales
and by two genera of
Actinomycetales
. Biosynthesis by
Serratia marcescens
occurs over a relatively narrow range of temperatures, although the bacteria grow over a broad range. When cultures of
S. marcescens
were incubated at 27 C in 1.0% casein hydrolysate, viable count and protein attained maximal values within 24 to 48 h, whereas prodigiosin did not reach a maximum until 96 h. The greatest amount of pigment was synthesized when cultures were in the senescent phase of growth. Suspensions of nonproliferating bacteria incubated at 27 C in only L-alanine also synthesized prodigiosin, although at a slower rate than growing cultures. Kinetics of growth for the wild-type, red
S. marcescens
and a white mutant were identical when incubated at 27 C, but the wild type produced abundant pigment. These results plus other data obtained from the literature suggest that prodigiosin is a secondary metabolite. The importance of this proposal to understanding the function of prodigiosin in
S. marcescens
is discussed.
Quantitative Detection of Type A Staphylococcal Enterotoxin by Laurell Electroimmunodiffusion
Authors: Gasper E. , Heimsch R. C. , Anderson A. W.
Published: December 2020

The detection of staphylococcal enterotoxin A by the quantitative technique of electroimmunodiffusion is described. High dilutions of type-specific rabbit antiserum were used in 1% agarose gels, 1 mm thick, and prepared in 0.05-μg barbital buffer, pH 8.6. Volumes of 10 μliters containing 1.5 to 10 ng of toxin were electrophoresed out of 4-mm diameter wells at 5 mA/cm width of gel. The precipitin cones formed were made visible by first immersing the agarose gels in 0.2 M NaCl and then overlaying the surface with the purified globulin fraction of sheep serum against rabbit globulin, followed by soaking of the gels in 1% aqueous cadmium acetate and staining with 0.1% thiazine red in 1% glacial acetic acid. Fully extended cones, 4 to 23 mm in length depending on toxin concentration and antiserum dilution, were developed in 2 to 5 h of electrophoresis, and visualization was achieved within 2 to 3 h. Because the method is qualitative, quantitative, simple, rapid, and sensitive, it offers a practical tool for the detection of small amounts of bacterial toxins in contaminated foods. The method should also qualify as a sensitive detection device in biochemical procedures which attempt to trace, detect, and identify biological substances in nanogram quantities, provided these substances are antigenic and capable of forming a precipitate with their specific antibodies.
Survival of Microorganisms in Laundered Polyester-Cotton Sheeting
Authors: Wiksell Joanne Clarquist , Pickett Mary S. , Hartman Paul A.
Published: December 2020

The effects of wash-water temperature, cold-water or regular detergent, wash-cycle design, drying, and drying temperature on survival of four microorganisms on polyester-cotton sheeting were examined.
Escherichia coli
T3 bacteriophage survived washing at 24, 35, 46, and 57 C, but not at 68 C.
Serratia marcescens
survived only the lowest three wash temperatures. Levels of residual
Staphylococcus aureus
were diminished at the highest two wash temperatures, but survival was substantial even at 68 C. Counts of
Bacillus stearothermophilus
spores were not altered appreciably by wash temperature. Type of detergent had no practical effect on observed counts. The regular wash cycle was significantly more efficient in removal of microorganisms than the permanent-press cycle. Counts, especially of the bacteriophage and the gramnegative bacterium, were decreased by drying; after drying, the effects of wash-water temperature on
S. aureus
and
B. stearothermophilus
were not significantly different. Microorganisms were transferred from inoculated to sterilized sheeting during laundering. The public health significance of these observations is discussed.
Factors Affecting the Growth of
Pseudomonas fluorescens
in Liquid Egg White
Authors: Nath K. R. , Baker R. C.
Published: December 2020

Pseudomonas fluorescens
grew rapidly in fresh egg albumen diluted with water. Growth of the bacteria in egg albumen was stimulated by the addition of carbohydrate and ovomucoid-rich egg exudate. Polyacrylamide-gel electrophoresis for residual egg albumen revealed extensive proteolysis of albumen inoculated with the organism. A fluorescent compound with absorption maximum at 408 nm was isolated from a defined salt medium inoculated with
P. fluorescens
. It shortened the lag phase and increased the final cell yield of the organism when added to the salt medium (100 μg/ml).
Synthesis of Glycols by Microbial Transformation of Some Monocyclic Terpenes
Authors: Mukherjee Barid B. , Kraidman Gary , Hill Ira D.
Published: December 2020

The transformation of three monocyclic terpenes by three soil microorganisms have been studied. The organisms were isolated on, and grew rapidly in, mineral salts medium containing the appropriate terpene substrates as sole carbon sources. These organisms belong to the class Fungi Imperfecti, and two of them have been tentatively identified as
Cladosporium
species. A
Cladosporium
species designated T
1
was isolated from terpene-soaked soil, using 1-menthene as the sole source of carbon. The major catabolic product isolated from the growth medium of this organism was found to be a cyclic 1,2-diol identified as
trans-p
-methane-1,2-diol. A similar but biochemically distinct
Cladosporium
sp. designated T
7
was isolated on D-limonene. After growth, the medium of this organism contained 1.5 g/liter of the analogous product,
trans
-limonene-1,2-diol. Minor quantities of the corresponding
cis
-1,2-diol were also isolated. The third organism, designated as laboratory culture T
8
, was isolated on 3-menthene and yielded a diol identified as
trans-p
-menthane-3,4-diol. From these results it is concluded that the formation of diols is a common intermediate in the fungal metabolism of monocyclic terpenes.
Simple Parabiotic Chamber for the Study of Microorganisms in Organ Culture
Authors: Powell Keith R. , Huth Harry J. , Cherry James D.
Published: December 2020

A simple parabiotic chamber which is easy to manipulate, does not leak, allows microscopic examination of organ cultures, and is easy to sterilize is described.
Optimum Temperature for Enterotoxin Production by
Staphylococcus aureus
S-6 and 137 in Liquid Medium
Authors: Vandenbosch Linda L. , Fung Daniel Y. C. , Widomski Matthew
Published: December 2020

The temperature for maximum toxin yield by
Staphylococcus aureus
S-6 and 137 in liquid medium cultured under aerobic conditions was determined to be 40 C.
Production of Yeast Invertase from Sauerkraut Waste
Authors: Hang Y. D. , Splittstoesser D. F. , Landschoot R. L.
Published: December 2020

Sauerkraut waste was found to be a favorable medium for the production of invertase (β-D-fructofuranoside fructohydrolase, EC 3.2.1.26) by
Candida utilis
.