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L M JONES

Publications and source records attributed to L M JONES.

At least 19 recordsLinked to original sources
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↗
PubMed1958

A recommended method for the preparation of monospecific Brucella sera.

A method is described in detail for the preparation of monospecific sera for typing brucella cultures. The importance of using entirely smooth cultures throughout the procedure is emphasized. A single intravenous injection of living brucellae in rabbits caused an active infection and the early appearance of high-titre antibodies. Sera obtained five to seven days after inoculation contained a higher proportion of specific antibodies than serum obtained ten days after inoculation. Trial absorptions of each serum sample were performed to determine the relative content of homologous and heterologous antibodies, so that the optimum proportions of absorbing cells to serum could be employed for the final absorption. In this manner sera were obtained which at a 1/160 dilution agglutinated the homologous antigen and at a 1/10 dilution did not agglutinate the heterologous antigen.Monospecific sera were used in typing 180 brucella strains isolated in Great Britain and other countries, and over 3000 cultures recovered from experimental infections. With the exception of two strains of Br. melitensis, all cultures were agglutinated to titre with only one of the monospecific sera.

Animals↗
PubMed1958

The use of gel diffusion precipitin plates in the study of Brucella.

The use of gel diffusion precipitin plates in the study of brucella is described.Cultures of Brucella melitensis yielded a diffusible precipitin antigen which produced lines with sera of rabbits, goats, and cattle that had been infected with either Br. abortus or Br. melitensis. The precipitin lines varied in number from one to three.A diffusible precipitin antigen could not be prepared from Br. abortus and Br. suis cultures by the methods which were effective in producing such an antigen from Br. melitensis.No precipitin reactions occurred with sera from cattle in brucella-free herds which had been inoculated with Strain 19 vaccine, although some of these sera were positive to the agglutination test.

Animals↗