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J B WILSON

Publications and source records attributed to J B WILSON.

At least 19 recordsLinked to original sources
PubMed1965

EGG YOLK FACTOR OF STAPHYLOCOCCUS AUREUS. II. CHARACTERIZATION OF THE LIPASE ACTIVITY.

Shah, D. B. (University of Wisconsin, Madison), and J. B. Wilson. Egg yolk factor of Staphylococcus aureus. II. Characterization of the lipase activity. J. Bacteriol. 89:949-953. 1965.-The staphylococcal egg yolk factor was characterized as a lipase. The enzyme had an optimal pH of 7.8, but the optimal pH of stability was 7. Substrate specificity data showed that the relative rate of hydrolysis was lowest with triacetin as substrate, was maximal with tributyrin, and decreased as the chain length of the acyl moieties increased. The enzyme showed an absolute requirement for a fatty acid acceptor like calcium, when the acyl moiety of triglyceride was water-insoluble. Magnesium, strontium, and barium functioned equally well as fatty acid acceptors. The enzyme was able to hydrolyze coconut oil, peanut oil, olive oil, and egg yolk oil.

Calcium↗
PubMed1964

CULTIVATION OF LEPTOSPIRAE. I. NUTRITION OF LEPTOSPIRA CANICOLA.

Stalheim, O. H. V. (University of Wisconsin, Madison), and J. B. Wilson. Cultivation of leptospirae. I. Nutrition of Leptospira canicola. J. Bacteriol. 88:48-54. 1964.-The nutrition of Leptospira canicola was investigated by use of synthetic media of suitable ionic strength. At an incubation temperature of 30 C, the minimal components were calcium, iron, magnesium, and ammonium ions, thiamine, and a fatty acid source; barium and strontium replaced calcium. Aspartic acid, glutamic acid, or methionine stimulated the rate and amount of growth; the best growth occurred in medium containing additional amino acids. Additions of cyanocobalamin or biotin permitted growth at 37 C. The stimulatory effects of added cyanocobalamin, biotin, pyridoxine, pantothenate, lipoic acid, or nicotinic acid were additive at 37 C, but not at 30 C. Fatty acids containing 14, 16, 17, or 18 carbon atoms supported growth; linoleic and linolenic acids were toxic. Glyceryl monooleate or trioleate, or Tween 40, 60, or 80 supported moderate to good growth; a mixture of monoolein and Tween 60, or Tweens 60 and 80 supported the best growth. Ten strains of L. canicola cultivated in a synthetic medium containing Tweens 60 and 80 attained cellular densities per ml of 10(7) to 4.0 x 10(7) organisms. L. canicola cells, resuspended in medium containing oleic-1-C(14) acid, incorporated label primarily into cellular lipids; a lesser amount was located in the protein fraction, and only trace amounts were found in the nucleic acid fraction. The rate of incorporation was not affected by added sodium acetate. L. canicola was found to have fatty acid decarboxylase activity.

Biotin↗
PubMed1964

CULTIVATION OF LEPTOSPIRAE. II. GROWTH AND LYSIS IN SYNTHETIC MEDIUM.

Stalheim, O. H. V. (University of Wisconsin, Madison), and J. B. Wilson. Cultivation of leptospirae. II. Growth and lysis in synthetic medium. J. Bacteriol. 88:55-59. 1964.-Differences were found in the ability of leptospirae to grow in a synthetic medium; 43 strains, consisting of 16 serotypes, were tested and designated as either type I or type II. Type I leptospirae did not grow; type II grew and could be subcultured. The lytic effect of several lipids was measured with Leptospira pomona and L. canicola as representatives of type I and II leptospirae, respectively. L. pomona organisms were rapidly lysed by the monoolein of the synthetic medium and by other lipids as well; L. canicola cells were consistently more resistant. Although both organisms incorporated similar amounts of label when incubated in the presence of oleic-1-C(14) acid, only L. canicola grew in a modified, nonlytic synthetic medium. No differences were found in susceptibility to lysis between virulent and avirulent L. canicola organisms. Mutant type I leptospirae grown in synthetic medium had increased resistance to lysis by surface-active agents; they were poorly agglutinated by antiserum. The role of protein in the growth and antigenicity of type I leptospirae is discussed.

Bacteriolysis↗
PubMed1963

Preservation by freezedrying and the stability of virulence of Salmonella typhimurium.

Differences in the ability to withstand freeze-drying were demonstrated among strains of Salmonella typhimurium. On the average, the number of viable cells in freeze-dried cultures stored at 5 C for 12 to 18 months was approximately one half as large as that found 24 hr after freeze-drying. The viability in samples stored at higher temperatures declined rapidly and was correlated with the dryness of the sample. The virulence for mice of three strains of S. typhimurium did not change appreciably when samples were kept for 1 or 2 years as freeze-dried samples stored at 5 C, or as agar cultures stored at 5 C or at room temperature.

Animals↗
PubMed1963

EGG YOLK FACTOR OF STAPHYLOCOCCUS AUREUS. I. NATURE OF THE SUBSTRATE AND ENZYME INVOLVED IN THE EGG YOLK OPACITY REACTION.

Shah, D. B. (University of Wisconsin, Madison) and J. B. Wilson. Egg yolk factor of Staphylococcus aureus. I. Nature of the substrate and enzyme involved in the egg yolk opacity reaction. J. Bacteriol. 85:516-521. 1963.-Some pathogenic staphylococci produce an opacity reaction when grown in media containing egg yolk. The egg yolk factor is a lipase with a requirement for a fatty acid acceptor, rather than any of the three lecithinases. Highest amounts of egg yolk factor were obtained in Heart Infusion broth rather than nutrient broth or Casman's synthetic medium. The lowest density lipo-protein (lipovitellenin) isolated by ultracentrifugation of egg yolk has been identified as the opacity-producing substrate. The lipase acts on the lipid moiety, resulting in alterations in the solubility of lipovitellenin. Lipolysis is optimal at pH 8. The optimal pH for the opacity reaction is at pH 5.5 and 8. The protein (vitellenin) in lipovitellenin has an isoelectric point at pH 5.5. It is proposed that slight alterations in the stabilizing lipid due to lipolysis and the very low solubility of vitellenin may drastically alter the solubility of lipovitellenin at pH 5.5.

Culture Media↗
PubMed1963

LEPTOSPIRAL COLONIAL MORPHOLOGY.

Stalheim, O. H. V. (University of Wisconsin, Madison) and J. B. Wilson. Leptospiral colonial morphology. J. Bacteriol. 86:482-489. 1963.-A sequence of apparent colonial types was observed with colonies of Leptospira pomona, L. canicola, L. icterohaemorrhagiae, and L. grippotyphosa in agar medium. Although some colonies of these serotypes had a different appearance initially, they eventually developed the mature or final appearance characteristic of the serotype. Colonies of freshly isolated, virulent cultures of L. pomona, L. canicola, and L. icterohaemorrhagiae were similar in appearance to colonies of avirulent strains of the same serotype. Additional studies of three stable and distinct colonial types of a laboratory strain of L. autumnalis revealed no differences in antigenicity, catalase activity, or mouse infectivity; however, differences in susceptibility to lysis by oleic acid were found. Although the colonial variants were stable during several in vitro variations, including growth in the presence of homologous antiserum and mutation to growth in a chemically characterized medium, rapid dissociation in vivo was found.

Animals↗
PubMed1962

Phenotypic alterations in the colonial morphology of Brucella abortus due to a bacteriophage carrier state.

Jones, Lois M. (University of Wisconsin, Madison), C. R. McDuff, and J. B. Wilson. Phenotypic alterations in the colonial morphology of Brucella abortus due to a bacteriophage carrier state. J. Bacteriol. 83:860-866. 1962.-In the course of examining a number of Brucella cultures with a brucellaphage, it was observed that B. abortus cultures of intermediate colonial morphology, which had a blue-gray colonial appearance, were not lysed within 24 hr; in 48 hr they had developed sticky white growth in the area of the phage drop. When this growth was streaked on agar plates, both white and blue-gray colonies developed. White colonies which were sticky always carried phage and upon restreaking always gave rise to both white and blue-gray colonies. White colonies which were not sticky were rough and phage resistant. Blue-gray colonies produced only blue-gray colonies, did not carry phage, and were similar to the parent in their response to phage. When sticky white colonies were incubated for 6 hr or more in phage antiserum, all phage was eliminated and only blue-gray colonies developed. It was believed that the sticky white colonies were carrier clones in which lysis was delayed until after cell division, thus resulting in the establishment of a colony containing some phage-free progeny. With the accumulation of phage, the colony became sticky. This effect may be caused by the action of bacteriophage enzymes on the cell walls. Brucellaphage had an extremely slow rate of adsorption on a culture of intermediate colonial morphology. A phage mutant which was more strongly lytic for cultures of intermediate colonial morphology was selected from the original phage. The adsorption rate of this phage was more rapid and the latent period shorter. A serological difference between phages could not be demonstrated.

Adsorption↗
PubMed1962

Glutamate metabolism in Brucella abortus strains of low and high virulence.

Dasinger, B. L. (University of Wisconsin, Madison) and J. B. Wilson. Glutamate metabolism in Brucella abortus strains of low and high virulence. J. Bacteriol. 84:911-915. 1962.-Brucella abortus strains of low virulence oxidize glutamate at a high rate, whereas strains of high virulence oxidize glutamate at a relatively low rate. Results indicated that this observation was not related to differences in pathway of glutamate oxidation or to differences in total enzyme activity. Permeability studies showed that the maximal rates of glutamate accumulation were 2.8 mumoles per 2 min per g (wet wt) for a strain of high virulence and 6.2 mumoles per 2 min per g for a strain of low virulence, but equal intracellular steady-state concentrations were attained by both types of strains. Evidence is presented which suggests that the site of glutamate oxidation is separate from the pool of glutamate being measured. Unequal rates of permeability at these sites could be the reason for the differences in rate of glutamate oxidation.

Brucella abortus↗