bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitation of the Bioenergetics of a Tuberculosis Infection in Chicks
Authors: Squibb R. L. , Solotorovsky M. , Beisel W. R.
Published: December 2020

Interaction of an avian tuberculosis infection with a known metabolizable energy yield of dietary corn oil in chicks was used to quantitate total host energy expenditure necessitated by the infectious process. Three trials in which two doses of inoculum were used resulted in mild and severe involvements. Trial 1 (mild) indicated that 6% and trials 2 and 3 (severe) that 96 and 93% of the energy supplied by known quantities of corn oil were utilized by the tuberculosis process. In the birds given the low level of inoculum, the degree of tuberculosis involvement, as measured by increased liver size, was correlated with increased total quantities of hepatic ribonucleic acid, monoglycerides, free fatty acids, free cholesterol, and glucose. All of these effects were observed prior to manifestations of clinical symptoms or failure of the chicks to consume all food offered.
Growth Characteristics of a Herpesvirus of Turkeys
Authors: Ash Ronald J. , Ware John D.
Published: December 2020

The herpesvirus of turkeys remains associated with cells attached to the culture vessel throughout its growth cycle. The level of infectious centers is essentially constant between 24 and 48 hr when the culture medium is unchanged. Thereafter, the number of infectious centers decreases. The cessation of virus synthesis is not due to insufficient numbers of uninfected cells or interferon production. Herpesvirus of turkeys does not replicate at 22 C and is similar to other herpesviruses in its sensitivity to interferon. The results define conditions to be considered in the preparation of infected cell suspensions commonly used as a vaccine against Marek's disease virus.
Bacteriological Survey of the Blue Crab Industry
Authors: Phillips Fred A. , Peeler James T.
Published: December 2020

During sanitation inspections of 46 crabmeat processing plants on the Atlantic and Gulf Coasts, 487 samples of whole crabs immediately after cooking, cooked crabs after cooling, backed or washed (or both) crab bodies and whole crab claws, as well as 1,506 retail units of finished product were collected and analyzed bacteriologically. The 1,506 retail units (1-lb [373.24-g] cans) included 518 cans of regular (special) meat, 487 cans of claw meat, and 501 cans of lump meat. Statistical analyses showed that crabmeat from plants in Mississippi, Louisiana, and Texas had higher counts in 19 of 24 cases for the four bacteriological indices than crabmeat from plants located along the Atlantic Coast and the Gulf Coast of Florida. Aerobic plate counts of retail units collected from a previous day's production were significantly higher than those collected on the day of inspection. Regular crabmeat had consistently higher aerobic plate counts than claw or lump meat. When the product was handled expeditiously under good sanitary conditions, the bacteriological results were significantly better than the results from plants operating under poor sanitary conditions. Crabmeat produced in plants operating under good sanitary conditions had the following bacteriological content: (i) coliform organisms average most-probable-number values (geometric) of less than 20 per g; (ii) no
Escherichia coli
; (iii) coagulase-positive staphylococci average most-probable-number values (geometric) of less than 30 per g in 93% of the plants; (iv) aerobic plate count average values (geometric) of less than 100,000 per g in 93% of the plants, with the counts from 85% of these plants below 50,000 per g.
Lipid Content of Antibiotic-Resistant and -Sensitive Strains of
Serratia marcescens
Authors: Chang Chuan-Yi , Molar Roger E. , Tsang Joseph C.
Published: December 2020

The lipid content of antibiotic-resistant, nonpigmented strain (Bizio) and antibiotic-sensitive, pigmented strain (08) of
Serratia marcescens
was studied. The resistant strain contains at least three times more total extractable lipid and phospholipid than the sensitive strain. Lysophosphatidylethanolamine, phosphatidylserine, lecithin, phosphatidylglycerol, phosphatidylethanolamine, and polyglycerolphosphatide were identified in the phospholipid fractions of both strains.
Physiological and Biochemical Changes Associated with Macroconidial Germination in
Microsporum gypseum
Authors: Dill B. C. , Leighton T. J. , Stock J. J.
Published: December 2020

A study was made of the metabolic processes associated with macroconidial germination in
Microsporum gypseum
. The optimum conditions for stimulation of endogenous respiration, changes in chemical composition as germination proceeds, and the uptake and synthetic fates of amino acids, glucose, and uracil were investigated. The assimilation and conversion of
14
C-glucose,
14
C-amino acids, and
14
C-uracil into the cell pool and into trichloroacetic acid-precipitable material were studied during the early stages of germination (i.e., prior to germ-tube emergence). The macroconidia were not metabolically inert for any significant period of time after exposure to germination conditions. Rather, the spores rapidly assimilated all metabolites and slowly converted them into macromolecules. Investigations of the effect of inhibitors of nucleic acid and protein synthesis prior to germ-tube emergence and during early germ-tube elongation suggested significant changes in metabolism and cell permeability may be correlated with the emergence of germ tubes. Radioactivity of incorporated glucose was found to be associated largely with the lipid fractions of the macroconidia early in germination.
Microtitration of
Bacillus cereus
Hemolysin
Authors: Coolbaugh James C. , Wende Reuben D. , Williams Robert P.
Published: December 2020

A microtiter procedure for the quantitation of
Bacillus cereus
hemolysin is described.
Miniature Tissue Culture Technique with a Modified Plastic Microplate
Authors: Hernandez-Baumgarten Eliseo M.
Published: December 2020

Plastic microplates were modified to accommodate four glass microscope slides as surfaces for cell cultivation. Tissue cultures grown on these slides can be utilized for fluorescent-antibody and other cytological staining techniques.
Significance of
Staphylococcus epidermidis
in the Clinical Laboratory
Authors: Marsik Frederic J. , Parisi Joseph T.
Published: December 2020

Susceptibility to 11 antibiotics was determined for 63 cultures of
Staphylococcus aureus
and 63 cultures of
Staphylococcus epidermidis
obtained at random from the clinical laboratory. The incidence of resistance to nine of these antibiotics was greater for
S. epidermidis
than for
S. aureus
. Studies of the minimal inhibitory concentration of these cultures to clindamycin showed that 61 cultures of
S. aureus
were susceptible whereas only 46 cultures of
S. epidermidis
were susceptible to this antibiotic. Although cultures of
S. aureus
were more active in the production of seven virulence factors, some cultures of
S. epidermidis
produced virulence factors. By successive cultivation in increasing concentrations of clindamycin, resistant variants were obtained for 10 cultures of
S. aureus
and 3 cultures of
S. epidermidis
. The presence of subinhibitory concentrations of clindamycin inhibited the production of some virulence factors by the resistant variants. In view of the greater resistance of
S. epidermidis
to antibiotics and its ability to produce virulence factors, its isolation in the clinical laboratory should not be regarded lightly.
Isolation and Partial Characterization of a Mycotoxin from
Penicillium roqueforti
Authors: Wei Ru-Dong , Still Paul E. , Smalley E. B. , Schnoes H. K. , Strong F. M.
Published: December 2020

Extracts of pure cultures of
Penicillium roqueforti
isolated from toxic feed samples and of
P. roqueforti
NRRL 849 were lethal to rats by either intraperitoneal or oral administration. Purification studies guided by this test led to the isolation of a major toxin which showed intraperitoneal and oral median lethal dose values in weanling rats of 11 and 115 mg/kg, respectively. Partial characterization of the crystalline compound, C
17
H
20
O
6
, by infrared, ultra violet, PMR, and mass spectroscopy, and by several chemical transformations indicated the presence of three C-methyl substituents plus one acetoxy, one aldehyde, and one α,β-unsaturated ketone group. Two oxygen atoms are present either in epoxide or ether form.
Microbial Toxicity of Isopropyl Myristate Used for Sterility Testing of Petrolatum-Based Ophthalmic Ointments
Authors: Tsuji Kiyoshi , Robertson John H.
Published: December 2020

The toxicity of isopropyl myristate (IPM) to microorganisms varies from lot to lot and between manufacturers. The toxicity is not directly proportional to the number and level of IPM homologues present nor to the small quantities of fatty acids, alcohols, aldehydes, or ketones found in both filter- and heat-sterilized IPM. The toxicity of IPM, both filter- and heat-sterilized, has no correlation with the usual physical and chemical characteristics of IPM but shows excellent correlation (correlation coefficient, r = 0.88) with the
p
H of a water extract of IPM. The toxic compounds can be removed and the toxicity of both filter- and heat-sterilized IPM can be reduced by basic alumina treatment. These findings may indicate that trace amounts of acidic catalysts remaining after production of IPM are responsible for the toxic effect.
Characterization of
Staphylococcus aureus
in a Pediatric Burn Unit
Authors: Smith Rodney F. , Bettge Carol L. , Dayton Sandra L. , Jorgensen James H.
Published: December 2020

A one-year study on an endemic strain of
Staphylococcus aureus
phage type 84/85 in a children's burn unit is described. The endemic strain rapidly colonized the burns and nares of acute patients after admission but was not isolated from a patient on admission. Nonendemic strains of
S. aureus
found on some new patients were mostly non-phage typable and did not prevail in burns. The endemic strain was rarely isolated from the nares and skin of reconstructive patients or from the nares of hospital personnel. The endemic strain did colonize the oral cavity, normal skin, and intestinal tract of some acute patients. Endemic and nonendemic strains of
S. aureus
from the burned children were compared in their biochemical activities and antibiotic sensitivities to two groups of
S. aureus
from one other local and one Danish burns unit. The latter groups of strains represented different combinations of staphylococcal phage group III strains. Each of the four groups of strains differed in production of hemolysins, Tween 80 hydrolysis, egg yolk reaction, and proteolysis of casein and gelatin. All of the strains were uniformly sensitive to gentamicin, oxacillin, and cephalothin. Only 4 of 162 strains tested were methicillin resistant. The endemic
S. aureus
strains of phage type 84/85 were uniformly resistant to eight other antibiotics including lincomycin and clindamycin. The endemic strain was not the known cause of a clinically documented infection in a group of 82 acute patients studied. The possible role of
S. aureus
strains of phage group III in burn grafting problems is discussed.
Isolation of
Serratia marcescens
on Deoxyribonuclease-Toluidine Blue-Cephalothin Agar
Authors: Farmer J. J. , Silva Freda , Williams D. R.
Published: December 2020

Serratia marcescens
was isolated on a new medium—commercial deoxyribonuclease agar with the addition of cephalothin (1,000 μg/ml) and Toluidine Blue (1,000 μg/ml). It was detected in water samples even though it comprised only 0.1 to 0.0001% of the total bacterial population.
Survival of Animal Tissue Cells in Primary Culture in the Absence of Serum
Authors: Orr Henry C. , Baker James , Cheesman Judy O.
Published: December 2020

The ability of cells from tissues of several species of animals to survive in primary culture without serum was tested. Of the species tested, cells from the kidneys of
Macaca mulatta
(rhesus) and
Cercopithecus aethiops
(vervet) monkeys and chicken embryo cells not only survived under these conditions, but indeed developed into confluent monolayer cultures. The addition of either serum or its globulin or albumin fraction enhanced the development of cell monolayers and permitted those cells unable to survive in the absence of serum to do so. Certain specific protein trypsin-inhibitors not of serum origin were unable to provide conditions necessary for cell survival or growth when used in place of serum proteins.
Tuberculin Activity of Mycobacterial Fractions Obtained by Chromatography
Authors: Glenchur Harry , Burge Robert E. , Froman Seymour
Published: December 2020

Commercial purified protein derivatives (PPD), old tuberculin (OT), the bacillary extract, and the culture filtrate of
Mycobacterium tuberculosis
H37Ra were submitted to Sephadex G-25 and diethylaminoethyl (DEAE)-cellulose chromatography. The ability of the fractions obtained to elicit delayed dermal hypersensitivity in
M. tuberculosis
H37Ra-infected guinea pigs was studied. Skin tests with Sephadex fractions in
M. tuberculosis
H37Ra-infected guinea pigs showed that the tuberculin activity was localized in the first fraction. All other Sephadex fractions were nonessential and nonspecifically irritating. Fractions from chromatography of Sephadex G-25 fraction 1 on DEAE-cellulose columns showed that all but the first were able to elicit delayed hypersensitivity reactions. There was a variability in the capacity to elicit the tuberculin reaction according to the fraction injected and the stage of tuberculous infection in guinea pigs. Compared to the others, the seven lots of commercial PPD were variable in composition and content. They contained both essential and nonessential materials for the tuberculin reaction. Sephadex fraction 1 would appear to be a better tuberculin as it excludes nonessential nonspecifically irritating elements and contains the complement able to elicit the tuberculin reaction. Its methodological simplicity would be economically advantageous.
Cellulolytic Bacteria Associated with Sloughing Spoilage of California Ripe Olives
Authors: Patel Ishwarlal B. , Vaughn Reese H.
Published: December 2020

Sloughing spoilage of California ripe olives during processing is characterized by severe softening, skin rupture, and flesh sloughing. It was assumed that cellulolytic activity was responsible for skin rupture and sloughing of flesh, and so a deliberate search was made for cellulolytic bacteria from olives undergoing sloughing spoilage. A bacterium identified as
Cellulomonas flavigena
was highly cellulolytic, attacking filter paper, carboxymethyl cellulose (CMC) gel, and olive tissue. Other bacteria attacking CMC, but not filter paper, enhanced the activity of the
Cellulomonas
strain when grown in mixed culture, although they did not, in pure culture, have any effect on filter paper. These latter cultures (all degraded olive tissue) represented the genera
Xanthomonas, Aerobacter
, and
Escherichia
. Other noncellulolytic bacteria belonging to the genera
Alcaligenes, Kurthia
, and
Micrococcus
also were used for study of mixed culture fermentation of cellulose by
C. flavigena
. Cellobiose accumulation at levels of 1.0% (w/v) and above suppressed growth of
C. flavigena
.
Presence of Thermophilic Bacteria in Laundry and Domestic Hot-Water Heaters
Authors: Brock Thomas D. , Boylen Kathryn L.
Published: December 2020

Thermophilic bacteria resembling
Thermus aquaticus
were isolated from hot water taken from domestic and commercial hot-water tanks. Cold water from the same locations never yielded thermophilic bacteria, suggesting that the bacteria were growing in the tanks. In contrast to the
T. aquaticus
isolates from hot springs, the present isolates were rarely pigmented. In general, the hotter sources more frequently yielded bacteria.
Influenza A Neuraminidase Antibody Assay with Sensitized Erythrocytes
Authors: Holston J. L. , Dowdle W. R.
Published: December 2020

Erythrocytes sensitized with purified neuraminidase (Hong Kong) antigens were used for assay of influenza A neuraminidase antibodies. The neuraminidase indirect hemagglutination test was equal to the neuraminidase hemagglutination-inhibition (enhancement) test and appeared to be better than the neuraminidase inhibition test for detection of fourfold or greater antibody rises in paired sera from influenza patients or vaccinees. It was better than both tests for detection of neuraminidase antibody. The neuraminidase indirect hemagglutination test is simple to perform and has the advantage of direct antigen-antibody assay.
Evaluation of the Corneal Test as a Laboratory Method for Rabies Diagnosis
Authors: Larghi O. P. , González L E. , Held J. R.
Published: December 2020

The corneal test (CT) for rabies diagnosis was evaluated in samples from 313 subjects of different species. Some of the subjects were inoculated experimentally and others were naturally infected. When the CT was compared with immunofluorescence staining and mouse inoculation tests on brains of the same subjects, a sensitivity of 41.7% and a specificity of 100% were found. The authors conclude that a positive CT result would confirm the diagnosis of rabies, but a negative one would not exclude the possibility of disease.
Spiral Plate Method for Bacterial Determination
Authors: Gilchrist J. E. , Campbell J. E. , Donnelly C. B. , Peeler J. T. , Delaney J. M.
Published: December 2020

A method is described for determining the number of bacteria in a solution by the use of a machine which deposits a known volume of sample on a rotating agar plate in an ever decreasing amount in the form of an Archimedes spiral. After the sample is incubated, different colony densities are apparent on the surface of the plate. A modified counting grid is described which relates area of the plate of volume of sample. By counting an appropriate area of the plate, the number of bacteria in the sample is estimated. This method was compared to the pour plate procedure with the use of pure and mixed cultures in water and milk. The results did not demonstrate a significant difference in variance between duplicates at the α = 0.01 level when concentrations of 600 to 12 × 10
5
bacteria per ml were used, but the spiral plate method gave counts that were higher than counts obtained by the pour plate method. The time and materials required for this method are substantially less than those required for the conventional aerobic pour plate procedure.
Algicidal Activity of a Surface-Bonded Organosilicon Quaternary Ammonium Chloride
Authors: Walters P. A. , Abbott E. A. , Isquith A. J.
Published: December 2020

The hydrolysis product of a quaternary amine-containing organosilicon salt, 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride, was found to exhibit algicidal activity while chemically bonded to a variety of substrates. Six representative species of
Chlorophyta, Cyanophyta
, and
Chrysophyta
were used to evaluate the algicidal activity. Substrate-bonded
14
C-labeled organosilicon quaternary ammonium salt when attached to nonwoven fibers was durable to repeated washings, and algicidal activity could not be attributed to slow release of the chemical.
Tissue Explants Used for Enhancement of Herpesvirus Isolations
Authors: Kalter S. S. , Eichberg J. , Heberling R. L. , Felsburg P. J.
Published: December 2020

Herpesvirus recovery from normal and experimentally infected simian tissues prepared into 10 to 20% homogenates was compared with that obtained by explanting these same tissues. The explant procedure was by far the more sensitive of the two methods. As a result, 8 herpesvirus isolations were obtained by conventional virus isolation procedures in contrast to 74 isolates when explants were made from these same tissue sources. There is also evidence to suggest that the explant method is more sensitive than the use of tissue homogenates for recovery of other viruses as well.
Isotopic Labeling of Embryo, Yolk Sac, and Intracellular Parasites of the Embryonated Hen's Egg by Yolk Replacement
Authors: Hurd Richard A. , Winkler Herbert H.
Published: December 2020

A technique is described which allows the replacement of 50% of the yolk of the embryonated hen's egg with large volumes of diverse but chemically defined solutions. By using an electrosurgical unit and a polyethylene tunnel, the procedure was performed on eggs from days 3 through 7 with greater than 90% surgical success and viability for the short term. More than 50% of the eggs replaced showed viability for 2 weeks, and a significant proportion went full term.
32
PO
4
and amino acids (
3
H and
14
C) added to the replaced eggs were incorporated into the macromolecules of the embryo and yolk sac as well as into parasitic rickettsiae cultivated in the replaced eggs. The incorporated
32
PO
4
was shown to be assimilated into a variety of biochemical species.
Pneumococcal Beta Hemolysin Produced Under the Effect of Antibiotics
Authors: Lorian Victor , Waluschka Alexandra , Popoola Bodun
Published: December 2020

The relationship between exposure of pneumococci to antibiotics and appearance of beta hemolysis (rather than the usual alpha hemolysis) was studied in 100 isolates. All strains were capable of producing beta hemolysis. This occurred at the edge of inhibition zones produced by methicillin and other antibiotics, but only if grown anaerobically and subsequently exposed to air at reduced temperatures. Autolysis of the pneumococci was necessary for the beta hemolysis to be produced. Beta hemolysis was optimal at
p
H 6.8; none occurred at
p
H 7.4. The concentration of red cells influenced the reaction: at 4% the extent of beta hemolysis was drastically reduced, which suggests that the lysin is not an enzyme.
Immune Response in Primates Vaccinated with Duck Embryo Cell Culture Rabies Vaccine
Authors: Lavender John F.
Published: December 2020

Adult rhesus monkeys (
Macaca mulata
) were vaccinated with four inactivated rabies vaccines, including two cell culture vaccines, one zonal purified cell culture vaccine, and a 10% extracted duck embryo vaccine. The vaccines were potency tested by both National Institutes of Health (NIH) and Habel methods and passed one or both tests. However, a vaccine having acceptable potency by one method frequently failed or was marginal by the other procedure. Groups of three monkeys were inoculated with each vaccine by one of two schedules. The first consisted of four weekly 1-ml doses followed by a 1-ml booster dose at 6 months, and the second consisted of seven daily 1-ml doses of vaccine with no booster. Both zonal purified and extracted duck embryo vaccines induced detectable neutralizing antibody by day 7 with either schedule, and antibody titers elicited by the cell culture vaccine remained high through 210 days. However, antibody titers produced by the 10% duck embryo vaccine dropped sharply after their 28-day peak. Duck embryo cell culture vaccines with low or marginal potency as measured by Habel or NIH tests still produced rapid, high levels of serum-neutralizing antibody in primates. LD
50
or NIH and Habel tests as measured in mice were not necessarily good indices of antibody response in the primate host. The need for a cell culture potency test that will yield a more predictable correlation with the definitive host's antibody response is discussed.
Production and Purification of Large Amounts of Rous Sarcoma Virus
Authors: Smith Ralph E. , Bernstein Eugene H.
Published: December 2020

Procedures are described for production and purification of large amounts of Rous sarcoma virus. The virus was produced by Rous sarcoma virus-transformed chicken embryo fibroblasts in roller culture which produced up to 6 mg of virus per day per liter of supernatant fluid. Various methods of concentrating virus were evaluated; pelleting yielded the best results in terms of recovery of infectious virus. Purification was achieved by means of successive velocity and equilibrium density centrifugation by using sucrose solutions made in low-salt buffer. A rapid method for the optical density measurement of virus concentration was also developed.
β-D-Phosphogalactoside Galactohydrolase of Lactic Streptococci
Authors: Molskness T. A. , Lee D. R. , Sandine W. E. , Elliker P. R.
Published: December 2020

β-D-Phosphogalactoside galactohydrolase (β-Pgal) was examined in a number of lactic streptococci by use of the chromogenic substrate
o
-nitrophenyl-β-D-galactopyranoside-6-phosphate. Specific activity of β-Pgal ranged from 0.563 units/mg of protein in
Streptococcus lactis
UN, to 0.120 in
S. diacetilactics
18-16. Essentially no β-D-galactoside galactohydrolase (β-gal) was found in these organisms when
o
-nitrophenyl-β-D-galactopyranoside served as the chromogenic substrate.
S. lactis
7962 was the one exception found. This organism contained rather high levels of β-gal, and very little β-Pgal could be detected. β-Pgal activity was examined in streptococci that differed widely in both their proteolytic ability and rates of lactic acid production during growth in milk. Differences in proteolytic ability did not influence β-Pgal synthesis; also, the rate of lactic acid production was independent of the level of β-Pgal present in the cell, since the rate of lactic acid production could be increased approximately fourfold without changing the amount of β-Pgal present in the cell. Various carbohydrates were tested as potential inducers of the enzyme. Although galactose, either as the free sugar or combined with glucose in lactose, was the only inducer, noninducing sugars such as mannose or glucose showed some ability to cause fluctuations in the basal level of β-Pgal. Cells growing in mannose or glucose exhibited about 30% of the maximal enzyme levels found in cells growing in lactose or galactose. No gratuitous inducers were found.
Location and Consequences of 1,1,1-Trichloro-2,2-bis(
p
-Chlorophenyl) Ethane Uptake by
Bacillus megaterium
Authors: Hicks G. F. , Corner T. R.
Published: December 2020

No detrimental effects of 1,1,1-trichloro-2,2-bis(
p
-chlorophenyl)ethane (DDT) were observed when cells of
Bacillus megaterium
were grown from small inocula in nutrient media containing up to 100 μg of DDT/ml. However, when the ratio of DDT to biomass of resting cells was held constant, levels of DDT as low as 1 μg/ml (0.5 μg/mg of cell dry weight) enhanced the rate of death in the population. The lethal action of DDT was both time- and dose-dependent so that higher doses required less time to effect the same killing than did lower doses. Intact cells bound a maximum of about 1.7 μg of DDT/mg of cell dry weight, of which about 75% was localized in the protoplast membrane. Much of the bound DDT was subsequently lost to the suspending medium and the aqueous stability of the returned DDT was enhanced, possibly by association with solubilized cell materials. A small quantity of bound DDT was converted to 1,1-dichloro-2,2-bis(
p
-chlorophenyl)ethane, which was released from cells somewhat faster than DDT. Apparently the lethal action of DDT was related to its binding in the membrane, but respiration was not inhibited. The atypical macroscopic appearance of membranes isolated from treated cells suggested that cell death may result from altered membrane chemistry.
Effect of Phosphate and Other Anions on Trimethylarsine Formation by
Candida humicola
Authors: Cox Donald P. , Alexander Martin
Published: December 2020

Phosphate inhibited the formation of trimethylarsine from arsenite, arsenate, and monomethylarsonate, but not from dimethylarsinate, by growing cultures of
Candida humicola
. Phosphite suppressed trimethylarsine production by growing cultures from monomethylarsonate but not from arsenate and dimethylarsinate, and hypophosphite caused a temporary inhibition of both proliferation and the conversion of these three arsenic sources to trimethylarsine. Resting cells of
C. humicola
derived from cultures grown in arsenic-free media generated the volatile arsenical only after a lag phase. High antimonate concentrations reduced the rate of conversion of arsenate to trimethylarsine by resting cells, but nitrate was without effect.
Nursery Outbreak of
Pseudomonas aeruginosa
: Epidemiological Conclusions from Five Different Typing Methods
Authors: Bobo R. A. , Newton E. J. , Jones Lois Faye , Farmer L. H. , Farmer J. J.
Published: December 2020

In April 1971, nine cases of
Pseudomonas aeruginosa
septicemia occurred in a high-risk nursery. The epidemiology of the outbreak was studied by pyocin production, pyocin sensitivity, serological typing, antibiotic susceptibility, and phenotypic properties such as colonial morphology, pigment, and hemolysis. Ten isolates of
P. aeruginosa
were recovered from 9 newborn infants and from 13 environmental sources. Twenty-one of the 23 isolates had identical pyocin production patterns against 60 different indicator strains and were of the same serotype. These 21 isolates were designated as the “outbreak strain”; the other 2 isolates had no epidemiological significance. The results of pyocin sensitivity, antibiotic susceptibility tests, and phenotypic properties were dissimilar. They would yield incorrect epidemiological conclusions if used alone. The outbreak strain dissociated in vitro and these phenotypic changes accounted for the variable results by the latter three typing methods. Although the precise mode of introduction of the organism into the nursery could not be determined in retrospect, the epidemiological data strongly suggested that one infant contracted a
P. aeruginosa
infection, and this strain spread throughout the nursery by means of contaminated resuscitation equipment.
Cytological and Deoxyribonucleic Acid-Deoxyribonucleic Acid Hybridization Studies on
Lactobacillus
Isolates from San Francisco Sourdough
Authors: Sriranganathan N. , Seidler Ramon J. , Sandine W. E. , Elliker P. R.
Published: December 2020

Molecular taxonomic and electron microscopy studies were performed on four bacterial isolates obtained from different sources of San Francisco sourdough (SD). These bacteria were first isolated by Kline and Sugihara who tentatively described them as a previously unreported species of heterofermentative
Lactobacillus
; they suggested the name
Lactobacillus sanfrancisco
. The guanine plus cytosine base composition (%GC) of the deoxyribonucleic acid (DNA) ranged from 38 to 40%. The possible genetic relatedness of these SD isolates to five known species of
Lactobacillus
with comparable GC contents was assessed in the present work by means of DNA-DNA hybridization competition experiments. Little or no DNA homology was observed between the SD bacteria and the known species. The SD bacteria exhibited a high degree of homology (>88%) among themselves, suggesting that the four isolates were identical taxonomically. Also, the electron photomicrographs revealed structures similar to those of gram-positive bacilli. Accordingly, since these SD isolates have the characteristic phenotypic and morphological properties of the genus
Lactobacillus
and are not related genetically to any known species, the tentative characterization by the above workers of these isolates as a new species is substantiated.
Technique for Differentiating Particles That Are Cell-Associated or Ingested by Macrophages
Authors: Gardner Donald E. , Graham Judith A. , Miller Frederick J. , Illing Joseph W. , Coffin David L.
Published: December 2020

Phagocytosis is a two-step process involving attachment and ingestion of particulate material. It is often difficult to determine under a light microscope whether the particles are actually ingested or are merely attached to the cell. A more accurate, easy to perform technique with the use of xylene has been developed for determining the difference between the attachment and ingestion of polystyrene latex spheres. The xylene treatment dissolves the extracellular spheres, leaving only the intracellular spheres to be counted by the experimenter to obtain a more accurate phagocytic index. This technique also allows an investigator to get an ingestion index, an attachment index, or both.
Autograft Rejection in Acutely Burned Patients: Relation to Colonization by
Streptococcus agalactiae
Authors: Smith Rodney F. , Dayton Sandra L. , Chipps Donna D.
Published: December 2020

The abrupt emergence of
Streptococcus agalactiae
in a population of acutely burned children is described in relationship to autograft rejection and the use of antibiotics to eradicate the organism from the patients.
Demonstration of a Deoxycytidine Kinase Activity in Extracts of
Bacillus megaterium
KM
Authors: Wachsman J. T. , Morgan D. D.
Published: December 2020

Extracts of
Bacillus megaterium
KM have been shown to possess a deoxycytidine kinase activity which functions optimally with guanosine triphosphate as the phosphoryl donor.
Resistance to Coliphage Infection Induced in
Escherichia coli
by Growth in the Presence of a Surfactant
Authors: Koransky Irwin H. , Anderson D. A.
Published: December 2020

Heavy slime exudates surrounding
Escherichia coli
cells grown in media containing 1% sodium dodecybenzene sulfonate apparently block adsorption of coliphages to susceptible strains.
Enumeration of
Escherichia coli
in Frozen Samples After Recovery from Injury
Authors: Ray B. , Speck M. L.
Published: December 2020

More than 90% of the surviving cells of
Escherichia coli
NCSM were injured after freezing in water at -78 C. Injury was determined by the ability of cells to form colonies on Trypticase soy agar with yeast extract but not on violet red-bile agar and deoxycholate-lactose agar. Exposure of the injured cells to Brilliant Green-bile broth and lauryl sulfate broth prevented subsequent colony formation on Trypticase soy agar with yeast extract. The freeze-injury could be repaired rapidly in a medium such as Trypticase soy broth with yeast extract (TSYB). The repaired cells formed colonies on violet red-bile agar and deoxycholate-lactose agar and were not inhibited by Brilliant Green-bile broth and lauryl sulfate broth. At least 90% of the cells repaired in TSYB within 30 min at 20 to 45 C and began multiplication within 2 h at 25 C. When the cells were frozen in different foods, 60 to 90% of the survivors were injured. Repair of the injured cells occurred in foods during 1 h at 25 C, but generally repair was greater and more reproducible when the foods were incubated in TSYB. The study indicated that the repair of freeze-injured coliform bacteria should be accomplished before such cells are exposed to selective media for their enumeration.
Microbial Phospholipid Synthesis as a Marker for Microbial Protein Synthesis in the Rumen
Authors: Bucholtz H. F. , Bergen W. G.
Published: December 2020

Phosphate uptake into intracellular inorganic phosphorus and cellular phospholipids and the relationship between cell growth and phospholipid synthesis were studied with suspensions of washed ruminal bacteria in vitro with
33
P-phosphorus. It was shown that ruminal bacteria accumulated inorganic phosphate at a low rate when incubated without substrate. Upon the addition of substrate, the rate of inorganic phosphorus uptake into the cells increased markedly, and phospholipid synthesis and cell growth commenced. There was a highly significant relationship (r = 0.98;
P
< 0.01) between phospholipid synthesis and cell growth. The specific activity of the intracellular inorganic phosphorus did not equilibrate with phosphorus medium. When ruminal contents from sheep fed a high or low protein diet were incubated in vitro, the rate of
33
P incorporation into microbial phospholipids was higher for the high protein diet. Since there was a high relationship between phospholipid synthesis and growth, rumen contents were collected before and various times after feeding and incubated with
33
P-phosphorus in vitro. The short-term, zero time approach was used to measure the rate of microbial phospholipid synthesis in whole rumen contents. In these studies the average specific activity of the intracellular inorganic phosphorus was used to represent the precursor pool specific activity. Microbial phospholipid synthesis was then related to protein (N × 6.25) synthesis with appropriate nitrogen-to-phospholipid phosphorus ratios. Daily true protein synthesis in a 4-liter rumen was 185 g. This represents a rate of 22 g of protein synthesized per 100 g of organic matter digested. These data were also corrected for ruminal turnover. On this basis the rate of true protein synthesis in a 4-liter rumen was 16.1 g of protein per 100 g of organic matter digested. This value represents a 30-g digestible protein-to-Mcal digestible energy ratio which is adequate for growing calves and lambs.
Yellow Fever Vaccine: Direct Challenge of Monkeys Given Graded Doses of 17D Vaccine
Authors: Mason Richard A. , Tauraso Nicola M. , Spertzel Richard O. , Ginn Robert K.
Published: December 2020

In rhesus monkeys a wide dosage range of 17D yellow fever (YF) vaccine extending to a level even below that recommended for vaccination of man elicited an immune response providing solid protection to challenge with virulent YF virus. Forty-three of 45 monkeys vaccinated with 10
2.3
or greater weanling mouse mean lethal doses of 17D vaccine were resistant to challenge 20 weeks later with virulent Asibi strain YF virus. Monkeys given graded doses of lesser amounts of vaccine were progressively more susceptible to challenge. With a vaccine dose ≥ 10
2.3
weanling mouse mean lethal doses, plaque neutralization (PN) seroconversion rates were 90% or greater, whereas hemagglutination-inhibiting (HI) and complement-fixing (CF) seroconversion rates were unrelated to vaccine dosage and were generally in the range of 20 to 80%. Ninety-six percent (51 of 54) of immune monkeys had PN titers ≥0.7 log
10
(fivefold) neutralization index as compared to approximately 55 to 65% who showed HI or CF titers ≥2 log
2
(fourfold) neutralization index. After challenge with Asibi strain YF virus, antibody titers of all three tests increaed equally. In rhesus monkeys PN antibody titers were well correlated with YF immunity, whereas HI and CF antibody titers were not.
Regulation of Staphylococcal Enterotoxin B: Effect of Anaerobic Shock
Authors: Morse Stephen A. , Mah Robert A.
Published: December 2020

The metabolism of glucose during enterotoxin B synthesis in
Staphylococcus aureus
S-6 was examined under anaerobic conditions in the presence and absence of nitrate. The repression of enterotoxin synthesis which occurs during the oxidative metabolism of glucose was relieved after a shift to anaerobic conditions; glucose was then converted primarily to lactic acid and was metabolized more rapidly, presumably to obtain the equivalent amount of energy available aerobically. A greater proportion of oxidized end products and evidently more energy per glucose molecule was produced in the presence of oxygen. Thus, available energy as judged by a change in the type and proportion of end products appears to be related to the degree of toxin repression. As expected, the addition of nitrate during anaerobic glucose metabolism prevented derepression of toxin synthesis.
Effects of Patulin and Method of Application on Growth Stages of Wheat
Authors: Ellis J. R. , McCalla T. M.
Published: December 2020

When a single, 100-μg/ml application of patulin, produced by
Penicillium urticae
Bainier, was applied to growth stages 7, 9, 10, and 10.1 (Feekes scale) of Lee spring wheat (
Triticum aestivum
L.), decreases in internodal elongation, floret number, seed weight, and seed number were observed. Yields were reduced according to the proximity of application prior to heading. Application of patulin to the soil in crystalline form and dissolved in aqueous solution were also investigated, and the solution method of application was found to be the treatment of choice. A single exposure of growing wheat plants to patulin can produce yield reductions similar to those observed in stubble-mulch farming.
Comparison of Direct and Indirect Solid-Phase Microradioimmunoassays for the Detection of Viral Antigens and Antiviral Antibody
Authors: Rosenthal Joel D. , Hayashi Kozaburo , Notkins Abner L.
Published: December 2020

Viral antigens were fixed to the surface of microtiter wells, and serial dilutions of antiviral antibody were added. The amount of antiviral antibody bound to viral antigens was determined by measuring the extent to which the antiviral antibody either inhibited the specific binding of
125
I-labeled antiviral immunoglobulin G (IgG) (direct technique) or enhanced the specific binding of
125
I-labeled anti-IgG (indirect technique). Immune complexes composed of viral antigens and antiviral antibody (human) could be detected by the binding of
125
I-labeled rheumatoid factor. Specific binding was influenced by the concentration of protein in the diluents used during the different steps of the procedure. A high concentration of protein in the diluent used with the viral antigens decreased specific binding, whereas a high concentration of protein in the diluent used with
125
I-labeled anti-IgG increased specific binding by decreasing nonspecific attachment of the labeled anti-IgG. Under the conditions employed, the titer of a given antiviral serum was several hundredfold greater by the indirect than by the direct technique.
Octene Epoxidation by a Cold-Stable Alkane-Oxidizing Isolate of
Pseudomonas oleovorans
Authors: Schwartz Robert D.
Published: December 2020

The isolation of an alkane-oxidizing strain of
Pseudomonas oleovorans
which maintains its viability at 5 C is described. This strain epoxidates 1-octene at a rate five times that of the parent strain. The most efficient substrates for induction of the epoxidase are C
7
, C
8
, and C
9
, although C
5
to C
12
also serve as growth substrates and inducers. The greater rate may be attributed to an enhanced general stability of the cells as opposed to a modification of the enzyme system involved.
Effect of Osmotic Stabilizers on
14
CO
2
Production by Bacteria and Blood
Authors: Zwarun A. A.
Published: December 2020

Evolution of
14
CO
2
by whole blood as well as by
Diplococcus pneumoniae, Haemophilus
sp.,
Pseudomonas aeruginosa, Pseudomonas diminuta
, and
Streptococcus pyogenes
was examined by using the BACTEC system. The control medium was JLI no. 6A culture vial containing 30 ml of enriched tryptic soy broth and 1.5 μCi of
14
C-substrate. Hypertonic media consisted of control medium with either 1 or 3% NaCl, 10% sucrose, and 5%, 10%, or 15% dextran. The most deleterious treatment to bacteria was 3% NaCl since it not only retarded
14
CO
2
production, but also prevented growth of
D. pneumoniae, Haemophilus
, and
P. diminuta
. The 10% sucrose treatment diminished
14
CO
2
output, although it did not retard growth of test organisms. This effect was probably due to
14
C-substrate dilution rather than to osmotic effects. Dextran had slight effect on
14
CO
2
production and slightly acidified the medium. Of the treatments tested, only 10% sucrose reduced normal output of
14
CO
2
by whole blood. This also is probably due to
14
C-substrate dilution. It appears that 10% sucrose is potentially the most useful osmotic agent for radiometric techniques since, although bacterial
14
CO
2
production is lowered, blood
14
CO
2
is lowered also.
Quantitative Assessment of Hemadsorption by Myxoviruses: Virus Hemadsorption Assay
Authors: Hahon Nicholas , Booth James A. , Eckert Herbert L.
Published: December 2020

The standardization and quantitative evaluation of an assay for myxoviruses, based on the enumeration of individual infected clone 1-5C-4 cells manifesting hemadsorption within 24 h of infection, are described. Hemadsorption was detectable earlier than immunofluorescence in infected cells or hemagglutinins in culture medium. The relationship between virus concentration and cells exhibiting hemadsorption was linear. The assay was highly precise, sensitive, and reproducible.
Microbial Hydroxylation of 5-Anilino-1,2,3,4-Thiatriazole
Authors: Theriault Robert J. , Longfield Thomas H.
Published: December 2020

Two hundred eighty-five fungi, including 100 basidiomycetes and 35 yeasts, 75 actinomycetes, and 40 bacteria were screened for their ability to convert 5-anilino-1,2,3,4-thiatriazole (AT) to 5-(
p
-hydroxyanilino)-1,2,3,4-thiatriazole (
p
-HT). Eleven cultures were found that formed
p
-HT, which was isolated and whose structure was determined.
Aspergillus tamarii
NRRL 3280 formed 8.6 g of
p
-HT/liter from 10 g of AT/liter (78.9% conversion) in shaken flasks and 4.57 g of
p
-HT/liter from 6 g of AT/liter (69.8% conversion) in 30-liter fermentors. Washed cells of
A. tamarii
NRRL 3280 also carried out this conversion. 5-(
o
-hydroxyanilino)-1,2,3,4-thiatriazole (
o
-HT) was identified as a second product formed by
Aspergillus terreus
NRRL 1960.
An Anaerobic Chemostat That Permits the Collection and Measurement of Fermentation Gases
Authors: Kafkewitz D. , Iannotti E. L. , Wolin M. J. , Bryant M. P.
Published: December 2020

A chemostat was designed to allow anaerobic growth in the culture vessel in the absence of a continuous stream of O
2
-free gas. Produced gases were collected within the culture and collection vessels, and pressure build-up was prevented by allowing gases to expand into a collapsed football bladder. The culture overflow was collected in a flask, held at 0 C, that was emptied by applying a positive CO
2
pressure to the system.
Ruminococcus albus
, a H
2
and CO
2
-producing anaerobe, was used to test the operation of the apparatus. H
2
production was measured by sampling the various gas spaces of known volume and measuring H
2
concentration by gas chromatography. Measurement of accumulated fermentation gases and the effects of the accumulation on fermentations can be studied with the apparatus.
Flocculant and Chemical Properties of a Polysaccharide from
Pullularia pullulans
Authors: Zajic J. E. , LeDuy A.
Published: December 2020

An extracellular polysaccharide, PP-floc, was synthesized from glucose by
Pullularia pullulans
(or
Aureobasidium pullulans
) in a pilot plant batch fermentor containing 175 liters of culture medium. At 58 h of fermentation, the concentration of PP-floc was 1.03 g/100 ml, giving a 25.8% conversion of initial glucose to polysaccharide. The flocculant activity of the culture medium increased during the fermentation process and reached its maximum at 50 h of culture age. Less PP-floc (0.33 lb/ton of slimes [approximately 149.7 g/0.907 t]) was required to give the same flocculant activity as a synthetic polymer of acrylamide, Separan NP-10 (0.5 lb/ton of slimes [approximately 226.8 g/0.907 t]), at all temperatures from 25 to 100 C. The degree of inactivation of PP-floc and Separan NP-10 at elevated temperatures was almost identical, and they were completely inactivated at about the same temperature (80 C). PP-floc also gave better compaction of slimes than Separan NP-10 at all temperatures tested. PP-floc was soluble in water and its specific optical rotation was [α]
D
25
+ 194° in water (c, 0.4). PP-floc contained 83.3% carbohydrate, 3.2% protein, and 8.1% water. Glucose was found to be the principal sugar monomer with traces (>5%) of galactose and mannose present. Structural studies on the fractions of purified polysaccharide by methylation and by periodate oxidation techniques prove that PP-floc is linear and composed of α-(1 → 4) and α-(1 → 6) glucopyranosyl units in the approximate ratio of 2:1. The action of pullulanase on crude PP-floc suggested the ordered arrangement of two consecutive α-(1 → 4)-linked glucopyranosyl units flanked by α-(1 → 6)-linked glucopyranose residues.
Experience with an Image-Analyzing Computer in Virus Plaque Measurements
Authors: Scheirer Winfried
Published: December 2020

Due to the extremely fast and reliable plaque-number determinations, the image-analyzing computer is most useful for large screening programs involving plaque-reduction tests.
Tube-Shaking Attachment for Rotary Shakers
Authors: Manning Herbert L.
Published: December 2020

An inexpensive tube-shaking device has been developed that attaches to rotary shakers without interfering with the flask holders already present.
Singh’s
Aedes albopictus
Cell Cultures as Helper Cells for the Adaptation of Obodhiang and Kotonkan Viruses of the Rabies Serogroup to Some Vertebrate Cell Cultures
Authors: Buckley Sonja M.
Published: December 2020

Multiplication of rabies serogroup viruses, Obodhiang and kotonkan, was induced in vertebrate cell cultures by using Singh’s
Aedes albopictus
cell cultures as “helper cells.”