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.