bluuebunny/crossref_metadata_2025 huggingface dataset:
Production of
l
-Proline by
Kurthia catenaforma
Authors: Kato Jyoji , Horie So , Komatsubara Saburo , Kisumi Masahiko , Chibata Ichiro
Published: December 2020

A number of organisms were screened for their ability to produce
l
-proline.
Kurthia catenaforma
, which we recently isolated, was selected. A serine-requiring mutant, strain 45, produced about 1.5 times the amount of this amino acid that the parent strain did. In investigations of various media, it was found that approximately 30 ml of
l
-proline per ml was produced in shaken culture at 30 C in a medium containing glucose, urea, corn steep liquor, casein hydrolysate,
l
-aspartic acid, and inorganic salts. To study the effect of
l
-aspartic acid on the production of
l
-proline, various amino or organic acids were substituted for
l
-aspartic acid, and the changes during fermentation were investigated.
l
-Aspartic acid was not replaced by the compounds tested, and this acid appeared to increase growth during the later stages of fermentation with a concurrent increase in the production of
l
-proline.
Enhancement of Parainfluenza 2 Virus Hemagglutinin
Authors: John T. Jacob , Fulginiti Vincent A.
Published: December 2020

A comparison was made of the three previously described methods of enhancement of parainfluenza 2 virus hemagglutinin (HA): ultrasonic oscillation, adsorption to erythrocytes and elution (AE), and Tween-ether (TE) treatment. TE treatment resulted in the maximal elevation of HA titer, complete loss of infectivity, and the maximal loss of heat stability of HA. Ultrasonic oscillation caused the least elevation of HA titer, minimal loss of infectivity, and the least loss of heat stability of both HA and infectivity. The effect of AE remained intermediate. It is suggested that the changes produced by these three methods are varying degrees of disruption of virus particles. Growth studies on parainfluenza 2 virus are also presented.
Effect of Temperature on the Coproduction of Chlortetracycline and Tetracycline by
Streptomyces aureofaciens
Authors: Petty Milton A.
Published: December 2020

Five strains of
Streptomyces aureofaciens
of diverse origin and ability to incorporate chloride into chlortetracycline (CTC) were grown at five temperatures of incubation ranging from 20 to 31 C in media of high and low chloride content. Maximal accumulation of CTC and tetracycline (TC) occurred in the 23 to 25 C range. Departure from this range affected the different strains to various degrees in total accumulation. Lower temperatures favored a relative increase in the amount of CTC produced by all strains. Higher temperatures were conducive to the almost exclusive production of TC by some strains but at the expense of an 80 to 90% reduction in potential total yield obtained at lower temperatures. The optimal temperature for maximal biochemical chlorination by some strains of
S. aureofaciens
was less than the optimal temperature for maximal accumulation of the tetracycline nucleus.
Enhancing Effect of Alkalinization of the Medium on the Activity of Erythromycin Against Gram-negative Bacteria
Authors: Sabath Leon D. , Lorian Victor , Gerstein Deborah , Loder P. Bronwen , Finland Maxwell
Published: December 2020

The antibacterial activity of erythromycin was markedly enhanced by alkalinization of the culture medium or urine within the clinical range (
p
H 6.0 to 8.2). This effect was demonstrated against recent isolates of
Escherichia coli, Klebsiella pneumoniae, Enterobacter
sp., and
Pseudomonas aeruginosa
, as well as against
Staphylococcus aureus
and
Streptococcus faecalis
. The urine of normal volunteers was made alkaline by ingestion of sodium bicarbonate or acetazolamide (Diamox) during administration of 1.0 g of erythromycin every 8 hr; such urine was capable of inhibiting
E. coli
and
K. pneumoniae
even when diluted up to (in one instance) 128 times with broth of the same
p
H as the urine. Undiluted urine of the same subjects, without alkalinization, was seldom capable of inhibiting these organisms. The range of
p
H (6.6 to 8.6) over which the antibacterial effect was enhanced coincided with that over which there was decreasing ionization of a basic group.
Rhinovirus Plaque Formation in WI-38 Cells with Methylcellulose Overlay
Authors: Dolan Timothy M. , Fenters James D. , Fordyce Patricia A. , Holper Jacob C.
Published: December 2020

A sensitive, reliable plaque assay system is described for five rhinoviruses using freshly prepared methylcellulose overlay and human embryonic diploid cells. Circular plaques with irregular edges, 2 mm in size, were formed by rhinoviruses 1A, 2, 6, and 13 after 6 or 7 days of incubation. A fifth rhinovirus, 17, formed a 1- to 2-mm feather plaque after 14 days of incubation. Plaque counts of rhinoviruses 1A and 13 were not affected by varying the
p
H of the overlay from 6.9 to 7.5. Plaque sizes and plaque-forming unit values of high passage rhinoviruses 1A and 13 were equivalent when tested at 26, 31, or 36 C. The rhinoviruses tested were sensitive to incubation at 40 C or heating at 50 C. Enhancement of plaques was observed when Mg
++
was incorporated into agar overlays, but enhancement did not occur when Mg
++
was added to methylcellulose overlays.
Survey of Microorganisms for the Production of Extracellular Phytase
Authors: Shieh T. R. , Ware J. H.
Published: December 2020

A culture enrichment technique was used to isolate phytase-producing microorganisms. Also, microorganisms from various culture collections were tested for their phytase-producing ability. A number of the
Aspergillus niger
group produced extracellular phytase which dephosphorylated calcium phytate in acidic solution. A soil isolate,
A. ficuum
NRRL 3135, produced the most active phytase in a cornstarch-based medium. Production of phytase was strongly repressed by inorganic phosphates and required a high carbon to phosphorus ratio in the medium.
Sphaerotilus
Growing in a Continuous-Flow Apparatus
Authors: Dias F. F. , Okrend Harold , Dondero N. C.
Published: December 2020

Sphaerotilus natans
required calcium for the production of sheaths and probably requires calcium for growth as well, though at a lower concentration. Neither strontium nor barium substituted for calcium.
S. natans
grew attached to the culture vessels of the continuous-flow apparatus even when no sheaths were produced. Tentative evidence showed that the requirement for calcium is shared by the manganese-oxidizing species
S. discophorus
.
Electronically Controlled Continuous Culture Device
Authors: Eisler William J. , Webb Robert B.
Published: December 2020

A photocell-controlled continuous culture device, a Nephelostat, is described that maintains a wide variety of cultures of microorganisms in balanced growth. This Nephelostat controls concentrations of bacteria within ±3% over a cell concentration range of 10
6
to 10
9
cells per ml. Growth rates are recorded so that changes in the growth rate are observed over small increments of time. Spontaneous and caffeine-induced mutation rates of two strains of
Escherichia coli
were compared under Nephelostat and chemostat conditions.
Isolation of Shigellae
Authors: Taylor Welton I. , Schelhart Dorothy
Published: December 2020

Many enteric media are more efficient for the detection of salmonellae than of shigellae. Comparisons of three enrichment broths and three plating media were made during analysis of 1,405 stool specimens to choose a combination of media which would enhance detection of shigellae as well. Gram-Negative (GN), Selenite, and Silliker's Broths were streaked to E M B,
Salmonella-Shigella
(SS), and xylose lysine deoxycholate (XLD) Agars. The enrichment broths produced a twofold increase in isolations of both salmonellae and shigellae over direct streaking. All three broths performed equally well for
Salmonella
detection, but GN and Silliker's produced twice as many
Shigella
isolates as did Selenite. Comparison of the plating media showed that XLD was markedly more efficient than either E M B or SS Agar for the recovery of both genera. SS Agar was superior to E M B for isolation of salmonellae after enrichment, whereas E M B was better for isolation of shigellae by direct streaking. Both E M B and SS were more effective when used after GN and Silliker's than after Selenite. GN Broth and XLD Agar were the most efficient combination of media. During these analyses, 158 salmonellae and 49 shigellae isolates were obtained.
Simple Isolation of Antimycin A
1
and Some of Its Toxicological Properties
Authors: Hamilton P. B. , Carroll F. I. , Rutledge J. H. , Mason J. E. , Harris B. S. H. , Fenske C. S. , Wall M. E.
Published: December 2020

An unidentified actinomycete, RTI 246, was found to produce antimycin A
1
in high yield on a high protein cereal medium. The antibiotic compound was extracted from the cells and isolated in pure form by crystallization. It was identified by ultraviolet, infrared, nuclear magnetic resonance, and mass spectroscopy and by alkaline hydrolysis to antimycic acid and a neutral lactone. The intravenous LD
50
was 1.0 mg/kg in white mice, whereas the intraperitoneal LD
50
was 1.50 ± 0.19 mg/kg. Animals receiving an intraperitoneal injection displayed an incoordination of the hind limbs and impaired reflexes before showing signs of respiratory distress. These findings indicated that antimycin A
1
possesses a neurotoxic property separate from its well-documented property as a respiratory poison.
Prevalence of Serotypes of
Salmonella
Authors: Martin William J. , Ewing William H.
Published: December 2020

The distribution of species and serotypes of
Salmonella
among 2,498 cultures which were isolated in the United States and its territories is presented. These isolates were received for examination during the 12-month period between October 1, 1966 and September 30, 1967. These and other data obtained from the Salmonella Surveillance Summaries for the past five years indicate that a relatively small number of species and serotypes of
Salmonella
are regularly isolated from diagnostic specimens. Of approximately 1,300 presently known
Salmonella
species and serotypes, 33 account for almost 90% of the isolates reported from humans and approximately 80% of the isolates from nonhuman sources. The 50 most prevalent species and serotypes account for 97% of the isolates from humans. An abbreviated antigenic schema based on these 50 species and serotypes of
Salmonella
, in conjunction with adequate biochemical tests, permits complete bacteriological characterization of the common
Salmonella
Effect of Nitrofurans and Chlortetracycline on Microorganisms Associated with Shrimp
Authors: Waters Melvin E. , Handy M. K.
Published: December 2020

Nitrofuran AF-2 displayed greater inhibitory effect than did nitrofuran Z when a mixed bacterial culture, including several proteolytic bacteria, isolated from shrimp was subjected to these compounds in vitro. Nitrofuran Z exhibited greater bactericidal properties than did chlortetracycline in all cultures used. Only 10 μg of nitrofuran AF-2 per ml was sufficient to inhibit the growth of mixed bacteria in nutrient broth, whereas 50 μg of nitrofuran Z per ml was necessary to accomplish the same inhibition. A 50-μg amount of chlortetracycline per ml displayed about the same inhibitory effect as either 10 μg of AF-2 per ml or 20 μg of Z per ml. The isolated proteolytic bacteria showed greater suppression of growth when subjected to AF-2 than when subjected to Z; however, both nitrofurans were effective in preventing growth. The addition of either 1 μg of AF-2 per ml or 5 μg of Z per ml to nutrient broth inhibited the growth of
Achromobacter aquarmarinus,
whereas chlortetracycline was less effective, requiring about 20 μg to suppress growth to the same degree.
Acrylamide Gel Electrophoresis of Group A Streptococcal Cell Walls
Authors: Larsen Sandra A. , Webb C. Douglas , Moody Max D.
Published: December 2020

Patterns obtained by acrylamide gel electrophoresis of group A streptococcal cell walls were characteristic for M types 1, 2, 3, 4, and 5, respectively. Best results were obtained with cell walls which had been solubilized with a phenol-acetic acid-water mixture. The method will make it possible to compare group A streptococci of epidemiological and clinical significance and to separate components for more critical analysis.
Electronic Data Processing System for the Clinical Microbiology Laboratory
Authors: Amsterdam Daniel , Schneierson S. Stanley
Published: December 2020

Owing to the increased volume of laboratory services and the shortage of skilled medical microbiologists who presently spend up to 30% of their time in clerical matters, pragmatic applications of electronic sorting techniques and computers should be considered to alleviate this problem. Moreover, surveillance of the hospital community, with particular reference to changing patterns of microbial resistance and the distribution of potentially infectious pathogens, requires detailed information which can be readily supplied by electronic sorting analysis. Mark-sense and prescored Port-A-Punch IBM cards were used to: (i) analyze antibiotic susceptibility data; (ii) tabulate total test loads according to conditions set down by the American Society for Clinical Pathologists; and (iii) to prepare a bacteriological report on the surveillance of hospital infections. After proper sorting and analysis, the cards also serve as a convenient reference file in the laboratory for pertinent information recorded by either blackening the appropriate areas (mark-sense style) or pushing out the preperforated rectangular holes with a simple inexpensive board and stylus (Port-A-Punch). No one scheme can fulfill the requirements of all laboratories or purposes, but ideas contained herein might serve as starting points for the design of similar systems in other laboratories.
Bacterial Infection of Washed and Unwashed Eggs with Reference to Salmonellae
Authors: March B. E.
Published: December 2020

A survey of eggs in the Fraser Valley area of British Columbia was conducted to determine the level of bacterial contamination on washed and unwashed shell eggs and the incidence of
Salmonella
infection in shell eggs. Samples of eggs were taken from 15 grading stations. Determinations of eggs from 87 shipments showed that a higher proportion of eggs was heavily contaminated (>5-million organisms per egg) after washing than as received at the grading stations. This finding suggests the need for the development of more satisfactory washing procedures. No salmonellae were detected in the 180 samples (3,995 eggs) which were examined. It was concluded that
Salmonella
contamination of intact shell eggs does not constitute a serious health hazard in eggs from this area.
Effects of Polyurethane Foams on Microbial Growth in Fuel-Water Systems
Authors: Cooney J. J.
Published: December 2020

Four, open-cell, ester-base polyurethane foams were examined for their effect on growth of fuel-utilizing organisms in jet fuel-water systems. Three foams contained a potential biocide, tetraethylthiuram E (0.66%), sodium omadine (0.07%), or zinc omadine (0.07%), all w/v. These were compared with a control foam which did not contain an additive. Each foam was examined in fuel-water systems containing JP-4 fuel, JP-4 fuel plus 0.1% anti-icing additive (AIA), or JP-5 fuel. Pure cultures of a fuel-grown bacterium,
Pseudomonas aeruginosa
, and of a fuel-grown fungus,
Hormodendrum (Cladosporium)
sp., served as test organisms. In control cultures without foam and in cultures containing control foam,
P. aeruginosa
achieved maximum stationary-phase populations of approximately 10
8
viable cells per ml, and
Hormodendrum
sp. produced an extensive mycelial mat. In the three fuel systems examined, tetraethylthiuram E- and sodium omadine-containing foams had little effect on growth of the bacterium; foam with zinc omadine decreased the rate of bacterial growth but had little effect on total populations. Tetraethylthiuram E decreased the rate of fungal growth and showed its greatest effect in JP-4 plus AIA. Foam with sodium omadine or zinc omadine markedly decreased fungal growth in all three fuel systems. The data suggest that either sodium omadine or zinc omadine in polyurethane foam may be a useful antifungal agent; and that tetraethylthiuram E and AIA could exert a synergistic effect, particularly at AIA concentrations which have been reported to occur in some field situations.
Microbiological Metabolism of Naphthyridines
Authors: Hamilton P. B. , Rosi D. , Peruzzotti G. P. , Nielson E. D.
Published: December 2020

Penicillium adametzi
and seven other species convert nalidixic acid, 1,4-dihydro-1-ethyl-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylic acid, to 1,4-dihydro-1-ethyl-7-hydroxymethyl-4-oxo-1,8-naphthyridine-3-carboxylic acid. Forty-seven other species from six orders of fungi seem to achieve the same conversion as judged by chromatographic and spectral evidence. Under special conditions,
P. adametzi
also produces a second metabolite which was identified as the corresponding 7-carboxylic acid. The metabolic attack on the ring substituent is identical with the pathway previously established with humans. No evidence was obtained for metabolic attack on the naphthyridine nucleus itself.
Arbovirus Plaquing in a Clonal Line (PS Y-15) of Porcine Kidney
Authors: Stim Thomas B. , Henderson Jack R.
Published: December 2020

Plaque development of 42 arbovirus serotypes, representing 17 serogroups, was studied in a clonal line (PS Y-15) of porcine kidney. The arboviruses plaqued within 3 to 7 days, with plaque diameters ranging from 1 to 5 mm. Mouse mortality and cell infectivity end points were compared with 24 arboviruses. Arbovirus LD
50
end points in mice exceeded the porcine kidney monolayer plaque-forming unitage end point with all 24 viruses compared.
Characterization of Bacteria by Gas Chromatography: Comparison of Trimethylsilyl Derivatives of Whole-Cell Hydrolysates
Authors: Farshtchi Davood , Moss C. Wayne
Published: December 2020

A method for the formation of the trimethylsilyl (TMS) derivatives of the whole-cell hydrolysate of bacteria was developed. The TMS derivatives were examined by gas-liquid chromatography. TMS profiles of various bacteria at the genus and species level were compared. Differences in TMS profiles of
Listeria, Neisseria
, and
Clostridium
were significant as were differences between the TMS profiles of
C. perfringens
and
C. sporogenes
. Two types of
C. perfringens
, two serotypes of
L. monocytogenes
, and one culture of
C. sporogenes
and
N. meningitidis
were studied. The possible application of TMS profiles as an aid in differentiating closely related organisms which are troublesome to separate by conventional means is discussed.
Factors Affecting the Persistence of
Staphylococcus aureus
on Fabrics
Authors: Wilkoff Lee J. , Westbrook Louise , Dixon Glen J.
Published: December 2020

The persistence of
Staphylococcus aureus
(Smith) on wool blanket, wool gabardine, cotton sheeting, cotton knit jersey, cotton terry cloth, and cotton wash-and-wear fabrics was studied. The fabrics were exposed to bacterial populations by three methods: direct contact, aerosol, and a lyophilized mixture of bacteria and dust having a high content of textile fibers. The contaminated fabrics were held in 35 or 78% relative humidities at 25 C. In general, the persistence time of
S. aureus
populations on fabrics held in 35% relative humidity was substantially longer when the fabrics were contaminated by exposure to aerosolized cultures or to dust containing bacteria than when contaminated by direct contact. In a 78% relative humidity, bacterial populations on the fabrics persisted for substantially shorter periods of time regardless of the mode of contamination or fabric type. Cotton wash-and-wear fabric (treated with a modified triazone resin) was the material on which populations of
S. aureus
persisted for the shortest time. This organism retained its virulence for Swiss mice after being recovered from wool gabardine swatches held 4 weeks in 35% relative humidity and 6 weeks in 78% relative humidity.
Elimination of Salmonellae from Animal Glandular Products
Authors: De Fiebre Conrad W. , Burck Kenneth T. , Feldman David
Published: December 2020

Methods for the elimination of salmonellae from selected powdered pharmaceuticals of animal glandular origin were studied. Terminal heat treatment under carefully controlled conditions was effective for pancreatin—a powder containing proteolytic, amylolytic, and lipolytic enzymes prepared from hog pancreas glands. Use of this method resulted in a significant reduction in the number of salmonella-positive batches and also reduced the testing procedures required to confirm the absence of viable salmonellae among the majority of samples tested. Powders such as stomach substance and thyroid, in which the biological activity is not enzyme in nature, were treated successfully with acidified organic solvents. Other methods were investigated but were not suitable because of a deleterious effect on the biological activity or physical properties of the product or an inability to effect salmonella elimination.
Fungi Isolated from Flue-cured Tobacco at Time of Sale and After Storage
Authors: Welty R. E. , Lucas G. B.
Published: December 2020

The fungi isolated from 100 samples of flue-cured tobacco from 12 markets in 2 tobacco belts comprised 11 genera, including 10 species of
Aspergillus
. The mean percentage per sample isolated from 62 samples of tobacco from Middle Belt markets was
Alternaria
, 40.6%;
Aspergillus niger
, 47.8%;
Aspergillus repens
, 38.0%; and
Penicillium
, 25.8%. The mean percentage per sample isolated from 38 samples of tobacco from Old Belt markets was
Alternaria
, 74.0%;
Penicillium
, 52.5%;
Aspergillus repens
, 38.0%; and
Aspergillus ruber
, 36.2%. Damaged (74 samples) and nondamaged (26 samples) stored tobacco yielded species of six genera of fungi, including eight species of
Aspergillus
. Species of
Aspergillus
and
Penicillium
were commonly isolated from both damaged and nondamaged tobacco, whereas species of
Alternaria, Cladosporium, Fusarium
, and
Rhizopus
were isoalted more frequently from nondamaged tobacco. The fungi that occurred in the highest population in damaged tobacco were
Aspergillus repens, A. niger, A. ruber
, and
Penicillium
species.
Membrane Filter-Fluorescent-Antibody Method for Detection and Enumeration of Bacteria in Water
Authors: Guthrie Rufus K. , Reeder Dennis J.
Published: December 2020

A technique which employs nonfluorescing membrane filters and specific fluoresceinisothiocynate—labeled antiserum has been successfully used in the identification and enumeration of known species of
Escherichia coli
which have been added to natural populations of bacteria found in water. The quantitative results compared favorably with those of standard tests. The use of a dissecting microscope with an external lighting arrangement provided a simple requirement for equipment. This method may be useful in monitoring specific bacterial types from waters which were being monitored for specific pollution.
Significance of Hemolytic Colonies in Throat Cultures
Authors: Quinn Robert W. , Lowry P. Nye
Published: December 2020

These studies indicate that a single strain of hemolytic streptococci almost exclusively predominates the bacterial flora in patients with streptococcal infections and in the carrier state. One can proceed with confidence that, in isolating streptococci from throat swabs cultured on blood-agar plates, only a single hemolytic colony need be picked for serological grouping and typing.
Pseudomonas aeruginosa
for the Evaluation of Swimming Pool Chlorination and Algicides
Authors: Fitzgerald G. P. , DerVartanian M. E.
Published: December 2020

Concentrations of ammonia and the chlorine stabilizer, cyanuric acid, which could be expected in swimming pools decreased the rate of kill by chlorine of the potential pathogen,
Pseudomonas aeruginosa
. The effect of cyanuric acid increased as the concentration of chlorine decreased, a fact of significance from a public health view. Quaternary ammonium algcides had little effect on the kill rate of chlorine, but an organic mercury algicide had a synergistic effect with chlorine when the chlorine activity was stressed by the addition of ammonia or the use of 100 times the normal concentration of bacteria. The effect of natural waters, rain, beaches, and swimming pools on the kill rate by 0.5 mg of chlorine per liter indicated that a treatment time of 1 hr or more was required to kill 99.9% of 10
6
Pseudomonas
cells per ml. The synergism of chlorine and the organic mercury algicide was also demonstrated with these waters and with sewage treatment plant effluents. The necessity of developing and using laboratory tests which simulate conditions in swimming pools with heavy loads of swimmers, as opposed to tests in chlorine demand-free conditions, is discussed. Samples taken from well-supervised swimming pools when the swimmer load had been especially high required treatment times of 1 to 3 hr to obtain 99.9% kills of the potential pathogen,
P. aeruginosa
, with 0.5 mg of chlorine per liter.
Immunofluorescence Identification of
Thermopolyspora polyspora
, the Causative Agent of Farmer's Lung
Authors: Gray Robert L. , Wenzel Frederick J. , Emanuel Dean A.
Published: December 2020

Farmer's lung is a serious disabling pulmonary disease found in agricultural workers. The disease is believed to be a hypersensitivity to the thermophilic actinomycetes, principally
Thermopolyspora polyspora
. This organism is difficult to stain with the usual bacteriological stains and thus far has not been demonstrated in the lung tissue by microscopic methods. In this paper, it is demonstrated that the fluorescent-antibody technique is a simple method for the positive identification of
T. polyspora
. The technique can also be used as a rapid screening test for the detection of antibodies to
T. polyspora
in the patient's serum. In addition, it opens up the possibility of the identification of
T. polyspora
in the lung tissue of patients with farmer's lung and makes available a means for the study of the immunological reaction in the lung parenchyma. No false positive or cross-reactions with
Thermoactinomyces vulgaris
or
Streptomyces griseus
could be demonstrated.
Biosynthesis of the Fungal Estrogen F-2 and a Naturally Occuring Derivative (F-3) by
Fusarium moniliforme
Authors: Mirocha C. J. , Christensen C. M. , Nelson G. H.
Published: December 2020

The fungal metabolites, F-2 and F-3, associated with estrogenism in swine, are produced by some races of
Fusarium moniliforme
isolated from toxic feeds.
Fluorescence Staining for the Determination of Cell Viability
Authors: Graham R. K. , Caiger P.
Published: December 2020

Primuline was shown to differentiate between viable and nonviable yeast cells taken from certain environments; the technique may be applicable to higher cells.
Microbial Hydrocarbon Co-oxidation. II. Use of Ion-Exchange Resins
Authors: Raymond R. L. , Jamison V. W. , Hudson J. O.
Published: December 2020

Anion-exchange resins, a weakly basic polystyrene-polyamine type and a macro-reticular type, IR-45 and IRA-93, respectively, were shown to significantly increase yields of acidic products in co-oxidation systems.
p
-Toluic, 2,3-dihydroxy-
p
-toluic, and α,α-cis,cis dimethylmuconic acids, resulting from the oxidation of
p
-xylene by three cultures of
Nocardia
, accumulated on the resin in shaken flasks or agar plates during the cultivation. Final product concentration increased with increasing resin concentration. Mineral balances were not affected if the resin was properly conditioned before use.
Interaction of Salt,
p
H, and Temperature on the Growth and Survival of Salmonellae in Ground Pork
Authors: Alford John A. , Palumbo Samuel A.
Published: December 2020

The interaction of temperature,
p
H, and NaCl concentration on the growth and survival of several strains of salmonellae has been determined in broth and ground pork. Growth of 23 strains occurred in broth at 30 C over a wide range of
p
H-NaCl combinations; at 10 C, growth was limited to only a few combinations. Cultures which would not grow at 10 C because of the
p
H-NaCl effect survived for long periods, however. In contrast, cultures which would not grow at 30 C remained viable for only a short time. Results in fresh ground pork were in close agreement with the broth studies. Salmonellae would not grow in ground pork stored at 4 C but would grow in pork containing 3.5% salt stored at 10 C. Salmonellae grew competitively with the natural background flora at 10 C even when the salmonellae constituted less than 5% of the initial flora, and the background flora would grow at a lower temperature than the salmonellae. The data show that, whereas decreasing temperatures increase the inhibitory effects of
p
H and NaCl, they decrease the lethal effects.
Populations of Dalapon-decomposing Bacteria in Soil as Influenced by Additions of Dalapon or Other Carbon Sources
Authors: Burge Wylie D.
Published: December 2020

The numbers of bacteria capable of decomposing the herbicide dalapon were determined for five soils by the most-probable-number method. Before treatment of the soils with dalapon, the numbers varied from 1,000 to 10,000 cells per g of soil. Incubation of the soils with dalapon resulted in large increases (100-fold) in two of three soils in which dalapon was decomposed rapidly. Lack of increase in numbers in spite of rapid decomposition in the other soil probably indicated breakdown by a chemical process or decomposition by fungi. In the remaining two soils, in which decomposition was slow in one and did not occur in the other, the initial numbers were at the low end of the range and the increase was small on incubation with dalapon. Addition of ground alfalfa or ground corn plant material to a soil did not result in significant increases in the numbers of dalapon-decomposing bacteria, either during or after decomposition of the plant material. Glucose depressed the rate of breakdown of dalapon in the soil and increased dalapon-decomposing
Bacillus
species rather than
Arthrobacter
and
Agrobacterium
species, which were found to increase on incubation with dalapon itself. The most-probable-number method appears to be a valuable tool for pesticide-ecology studies.
Direct Cord Reading Agar in Routine Mycobacteriology
Authors: Lorian Victor
Published: December 2020

A group of 2,081 sputum specimens were planted on Direct Cord Reading Agar. A total of 330 (16%) of these specimens produced positive cultures, 312 strains of
Mycobacterium tuberculosis
and 18 strains of atypical mycobacteria. The strains of
M. tuberculosis
showed visible cords on plates in 283 (90.8%) of the isolates and no atypical mycobacteria showed cording. The specimens from the newly admitted patients yielded, in 12 days, 59% of their total positives; 97.6% of these strains, identified as
M. tuberculosis
with the standard methods recommended by the National Communicable Diseases Center, exhibited cording visible directly on the agar. It is suggested that, for practical purposes, a colony exhibiting cording could be tentatively reported as “
M. tuberculosis
to be confirmed.”
Isolation of Anaerobic Bacteria from Human Gingiva and Mouse Cecum by Means of a Simplified Glove Box Procedure
Authors: Aranki Alexander , Syed Salam A. , Kenney Ernest B. , Freter Rolf
Published: December 2020

An anaerobic glove box constructed of clear flexible vinyl plastic is described. It is sufficiently inexpensive and simple in operation to be used not only in research but also in a clinical laboratory by technicians without special training. Conventional bacteriological techniques may be used inside the glove box for culturing and transferring anaerobic bacteria. The box may be heated to 37 C and thus serve as an anaerobic incubator as well, permitting inspection of cultures at any time. Media may be prepared and agar plates may be poured on the laboratory bench in the conventional manner. An overlay of trace amounts of palladium black catalyst over plated agar media reduces the medium to an oxidation-reduction (O-R) potential of - 300 mv within 2 days after introduction into the glove box. In spite of its greater simplicity, the system matched or excelled the roll tube method with respect to all parameters tested, including O-R potential obtainable in the media, O
2
concentration in the gas phase, and efficiency in isolating anaerobic bacteria from the mouse cecum. Comparative studies indicate that the conventional anaerobic jar method was inadequate for the isolation of strict anaerobes from human gingival specimens and from the mouse cecum. This was due to the exposure of specimens and media to air during plating on the open laboratory bench. Anaerobic jars were adequate for maintaining the proper conditions for growth of anaerobic bacteria once these had been established in the glove box.

Images
Motility Tracks: Technique for Quantitative Study of Bacterial Movement
Authors: Vaituzis Z. , Doetsch R. N.
Published: December 2020

A method for recording movements of bacteria in time and space on a single photograph is described. Quantitative information on the behavior of various motile organisms may easily be obtained for comparative studies. The method possesses certain advantages over cinematography, and illustrations of applications of the technique are presented.
Glutaraldehyde Inactivation of Virus in Tissue
Authors: Sabel Fred L. , Hellman Alfred , McDade Joseph J.
Published: December 2020

High concentrations of influenza virus and T3 coliphage were inoculated into mouse tissue blocks. Exposure of the inoculated tissue blocks to 5% alkaline glutaraldehyde resulted in rapid inactivation of both viral agents.
Transferable Drug Resistance Among
Enterobacteriaceae
Isolated from Human Urinary Tract Infections
Authors: Sieckmann Donna G. , Reed Norman D. , Georgi Carl E.
Published: December 2020

Fifteen sulfonamide-resistant cultures isolated from urinary tract infections in eastern Nebraska were screened for transferable drug resistance by three methods. Seven of the 15 resistant cultures could transfer resistance of varying levels to two or more chemotherapeutic agents. Transfer of drug resistance occurred without accompanying transfer of chromosomal traits and required cell to cell contact. In mixed culture, the number of drug-resistant recipients increased exponentially, reaching a plateau 2 hr after mixing. Spontaneous or artificial elimination of resistance was found to be a rare event. In addition, several drug-sensitive isolates from urinary tract infections were shown to be competent recipients of drug resistance determinants. From these data, it appears that the transferable drug resistance observed was mediated by R factors.
Influence of Pasteurization and Lye Treatment on the Fermentation of Spanish-Style Manzanilla Olives
Authors: Y Alcaĺa Jośe M Rodŕiguez De La Borbolla , Ferńandez-Díez Matías J. , Gonźalez-Cancho Fernando
Published: December 2020

The effect of lye concentration and pasteurization on the fermentation of Spanish-style Manzanilla green olives was investigated. Results showed that a rapid, normal fermentation always occurred when the proper lye was used, and only in the case of an inappropriate alkaline treatment could pasteurization help the growth of lactobacilli. Although pasteurization does not seem to affect color of processed olives, texture tests gave lower values for pasteurized samples than for those obtained from nonpasteurized olives.
Production of Antibody Against Conjugated Dipicolinic Acid (2,6 Pyridine Dicarboxylic Acid)
Authors: Disque Donald T. , Vincent William F.
Published: December 2020

An immunological precipitation system, with rabbit dipicolinyl antibody, was developed for the purpose of evaluating the role of spore dipicolinic acid as a specific haptenic determinant.
Intracellular Survival of Viral and Rickettsial Agents in Acetone at -60 C
Authors: Hahon Nicholas , Zimmerman W. Douglas
Published: December 2020

Viral and rickettsial agents, located intracellularly in cell monolayers, varied in their ability to survive exposure to acetone at -60 C.
Ester Production by
Pseudomonas fragi.
II. Factors Influencing Ester Levels in Milk Cultures
Authors: Reddy M. C. , Bills D. D. , Lindsay R. C.
Published: December 2020

Cultures of
Pseudomonas fragi
were grown at 21 C in sterile homogenized milk and reconstituted skim milk media supplemented with ethyl alcohol. Quantitative determinations of ethyl butyrate and ethyl hexanoate by gas-liquid chromatography showed definite increases in the concentrations of the two esters produced in these media in comparison to media not supplemented with ethyl alcohol. Supplementation with butyric acid in addition to ethyl alcohol generally elevated the ethyl butyrate concentration and usually depressed the cell count slightly. Aeration of any of the media during growth tended to reduce the cell population slightly. A relationship between increase in cell number and increase in concentration of esters during the growth of the culture was observed. Media containing high concentrations of ethyl alcohol plus milk fat or low-molecular-weight fatty acids were conducive to the production of a fruity aroma by
P. fragi.
Propagation of MM Virus in L Cells
Authors: Giron D. J. , Pindak F. F.
Published: December 2020

MM virus (mouse-brain stock) replicated to a limited extent in L cells without cytopathic effects; the average yield was less than 1 plaque-forming unit/cell. Passage in BHK-21 cells resulted in MM virus [MM(BHK)] which replicated to high titers (200 to 300 plaque-forming units/cell) in L cells with complete cytopathic effects. Appearance of mature MM(BHK) virus in L-cell cultures begins 4 hr after infection and is completed by 8 hr. Release of mature virus was slow (less than 1% at 8 hr) but was completed by 24 hr.
Propagation of MM Virus in Continuous Cell Lines
Authors: Pindak Frank F. , Schmidt Jerome P.
Published: December 2020

Baby hamster kidney (BHK), McCoy, and L cell lines were found to be suitable for isolation of MM virus from infected mouse brain tissue. The virus was recovered in high titer in the first passage in BHK and McCoy cells, with concomitant cytopathic effect (CPE). In L cells, virus yield was lower than in the other two cell lines and CPE was incomplete. Adaptation of the virus to BHK and McCoy cells by serial passages was evidenced by accelerated development of the CPE and increase in the virus titer. Plaques were obtained in all three cell lines when inoculated with infected mouse brain or with the tissue culture-propagated virus. In the BHK cells, the virus release preceded the appearance of CPE and maximal yield of virus was obtained after 1 to 3 days of incubation, depending on the size of inoculum. The BHK-propagated virus had the same lethality for mice as did the mouse brain-propagated stock, and there was no difference in the course of the disease caused by the two preparations.
Yellow Fever Vaccine. II. Antigenicity and Neurovirulence of a Vaccine Seed Free from Avian Leukosis Virus
Authors: Tauraso Nicola M. , Spector Sheldon L. , Kirschstein Ruth L. , Seligmann Edward B. , Farber Jane F.
Published: December 2020

Avian leukosis virus (ALV)-free candidate primary and secondary seed lots were indistinguishable from corresponding ALV-contaminated lots with respect to (i) potency as measured by titration in newborn and weanling mice and in the MA-104 plaque system, (ii) degree of viscerotropism as measured by viremia in monkeys, (iii) neurotropism as determined by the monkey neurovirulence test, and (iv) potency as determined by antibody response in monkeys inoculated by the intracerebral route.
Effect of Incubation Temperature on T-Agglutination Typing of
Streptococcus pyogenes
Authors: Padula Joseph F. , Facklam Richard R. , Moody Max D.
Published: December 2020

The temperature of incubation affected the typability of beta-hemolytic group A streptococci by T-agglutination tests. When strains could not be typed after routine incubation at 30 C, they were incubated at 22 to 25 C, and nearly a 10% increase in typability was achieved. The clinical source of the strains was related to their typability. Incubation at the lower temperature was required for successful typing of higher percentages of strains from the skin and other clinical sources than from the throat. Sixty per cent of the skin strains were represented by six serotypes. Of these, 53% of the strains required incubation at 22 to 25 C before they could be typed.
Combined Action of Carbenicillin and Gentamicin on
Pseudomonas aeruginosa
In Vitro
Authors: Sonne Minetta , Jawetz Ernest
Published: December 2020

The minimal inhibitory and minimal bactericidal concentrations of carbenicillin and gentamicin were determined for 10 strains of
Pseudomonas aeruginosa
isolated from the urinary tract. Combinations of the two drugs were tested for possible enhanced activity. Such enhancement was demonstrated in the inhibitory activity of combinations for eight strains. Striking bactericidal activity against five strains was achieved by the combination, whereas neither drug alone in low dosage was capable of bactericidal action. The possible mode of action and the possible merit of pursuing these preliminary findings are discussed.
Evaluation of a Washing Procedure in the Examination of Almonds for
Escherichia coli
Authors: Kokal Daniel
Published: December 2020

Almond samples were examined for
Escherichia coli
by the EC method employing two sample preparation procedures: direct inoculation and washing. The washing procedure was conducted under specified conditions with an eluent containing surfactant; results averaged only 60% of the incidence shown by the direct inoculation procedure.
Death of
Salmonella typhimurium
and
Escherichia coli
in the Presence of Freshly Reconstituted Dehydrated Garlic and Onion
Authors: Johnson Michael G. , Vaughn Reese H.
Published: December 2020

The kinetics of the decline of populations of
Salmonella typhimurium
inoculated into freshly reconstituted dehydrated onion and garlic powders was studied. Measurable bactericidal activity was observed for onion and garlic concentrations of 1 and 5% (w/v), respectively, with maximal death rates occurring for concentrations of 5 and 10%. At these concentrations, the decimal reduction times were 1.1 and 1.2 hr, respectively, for resting cell cultures and 1.8 and 2.1 hr, respectively, for growing cultures. Of the major volatile aliphatic disulfide compounds of onions,
n
-propyl allyl and di-
n
-propyl, at concentrations of 0.1%, showed a comparable activity against resting cells but only a bacteriostatic effect toward actively growing cultures, which overcame this effect in 2 to 6 hr. At comparable concentrations, growing cultures of
Escherichia coli
were as susceptible to garlic, but apparently more resistant to onion, than were those of
S. typhimurium.
Use of Hamsters for Potency Assay of Eastern and Western Equine Encephalitis Vaccines
Authors: Cole Francis E. , McKinney Robert W.
Published: December 2020

An antigen extinction test in hamsters is described. Comparative potency assays with guinea pigs and hamsters showed the latter to be a suitable, advantageous replacement animal in these assays.
L-Asparaginase Production by Various Bacteria
Authors: Peterson R. E. , Ciegler A.
Published: December 2020

Of 123 species of bacteria surveyed for L-asparaginase synthesis,
Erwinia aroideae
NRRL B-138 provided the highest yields.
Methods for Storing Oxidase Test Reagents
Authors: Barry A. L. , Bernsohn K. L.
Published: December 2020

Oxidase test reagents are notoriously unstable, but they can be held ready for use if frozen or if reagent-impregnated filter paper is kept dry.
Induction of Spheroplasts of
Pseudomonas aeruginosa
by Carbenicillin
Authors: Watanakunakorn Chatrchai , Hamburger Morton
Published: December 2020

Speroplasts of
Pseudomonas aeruginosa
were induced with carbenicillin. Morphological changes were observed as early as 1.5 hr after the initial exposure to carbenicillin.
Use of a Rapid Fluorescent-Antibody Staining Technique with Group A Streptococci
Authors: Freeburg Pat W.
Published: December 2020

A pilot study concerning a rapid fluorescent-antibody staining technique for identification of group A streptococci is described. Results indicate the method merits further study.
Lipase from
Pseudomonas fragi
. II. Properties of the Enzyme
Authors: Lu J. Y. , Liska B. J.
Published: December 2020

The optimal
p
H value of a lipase from
Pseudomonas fragi
was between 7.5 and 8.9, and a high reaction rate was observed at 54 C. Heating the enzyme solution at 63 C for 30 min inactivated only 27.6% of its activity; however, total inactivation was observed at 66 C after 1 hr and at 71 C after 10 min. The lipase was inhibited strongly by Fe
+++
and Fe
++
ions, and to a lesser extent by Co
++
, Cu
++
, Zn
++
. No inhibition was observed with Ca
++
or NaF. Ethylenediaminetetraacetate was effective in removing the toxicity of Fe
+++
. The activity of the enzyme was inhibited markedly by
p
-chloromercurobenzoate, but the effects of
N
-ethylmaleimide and iodoacetate were moderate. The enzyme was able to hydrolyze natural fats, synthetic triglycerides, and alcohol esters. The order of the rate of hydrolysis of some triglycerides under experimental conditions was, from the fastest to the lowest, trilaurin, tricaprin, tricaprylin, tripalmitin, tributyrin, tricaproin, and tristearin. The enzyme was capable of hydrolyzing methyl butyrate, but the rate of hydrolysis was about one-fifth that for triolein and one-thirteenth that for coconut oil. The enzyme lost its activity rapidly when held frozen, at 20 C, and at the extremes in pH. Glutathione, cysteine, and mercaptoethanol did not preserve the activity of the enzyme.
Relationships Among Coagulase, Enterotoxin, and Heat-stable Deoxyribonuclease Production by
Staphylococcus aureus
Authors: Victor R. , Lachica F. , Weiss Karl F. , Deibel R. H.
Published: December 2020

The relationship between heat-stable deoxyribonuclease and coagulase production was investigated in the interest of developing more rapid diagnostic and quantitative procedures for distinguishing toxigenic and pathogenic staphylococci from closely related saprophytic organisms.
Tremorgenic Toxin from
Penicillium palitans
Authors: Ciegler Alex
Published: December 2020

A strain of
Penicillium palitans
, implicated in the deaths of dairy cows, produces an intracellular tremorgenic mycotoxin.
Determination of Antibiotic Susceptibility of
Rickettsia
by the Plaque Assay Technique
Authors: McDade Joseph E.
Published: December 2020

Plaque formation by various rickettsiae was completely inhibited by commercial antibiotic discs impregnated with tetracycline, chloramphenicol, nitrofurantoin, and erythromycin; partial inhibition was observed around discs containing nalidixic acid and sulfisoxazole, but no inhibition was seen around discs containing cephalothin, ampicillin, oxacillin, kanamycin, polymyxin B, streptomycin, or penicillin.
In Vitro Susceptibility of
Neisseria gonorrhoeae
to Nine Antimicrobial Agents
Authors: Martin John E. , Lester Arzell , Kellogg Douglas S. , Thayer James D.
Published: December 2020

The in vitro action of nine antibiotics was tested by the agar streak method against 45 gonococcal strains isolated from penicillin-therapy failures. The penicillin susceptibility range of these strains was 0.003 to 1.32 μg/ml, and the tetracycline susceptibility range was 0.125 to 2.0 μg/ml. Minimal inhibitory concentrations of minocycline and doxycycline paralleled the activity of tetracycline and ranged from 0.125 to 1.0 μg/ml and 0.125 to 2.0 μg/ml, respectively. Rifampicin, with a narrow range of 0.5 to 1.0 μg/ml, inhibited 75% of the strains at 0.5 μg/ml. The range for cephaloridine and cephaloglycine was 0.5 to 20.0 μg/ml, but another cephalosporium derivative, cephalexin, exhibited greater activity in its range of 0.25 to 20.0 μg/ml. A semisynthetic penicillin, carbenicillin, with a range of 0.025 to 0.75 μg/ml, displayed more activity against the lower susceptible penicillin G gonococcal strains.