Pathogenicity and immunogenicity of streptomycin-dependent mutants of Brucella.

Simon, Ellen M. (University of Wisconsin, Madison) and David T. Berman. Pathogenicity and immunogenicity of streptomycin-dependent mutants of Brucella. J. Bacteriol. 83:1347-1355. 1962.-Streptomycin-dependent (Sd) mutants of Brucella suis and B. abortus were avirulent for guinea pigs whether selected in the presence of streptomycin only or streptomycin and normal or immune serum. Administration of large quantities of streptomycin to guinea pigs increased the numbers of organisms which could be recovered, but did not cause the development of progressive infections. Vaccination with Sd mutants of B. abortus diminished the pathological response of guinea pigs infected with a large challenge dose of virulent B. abortus, but equal numbers of organisms were recovered from vaccinated animals and unvaccinated controls. Vaccination with Sd mutants of B. suis protected some guinea pigs from small challenge doses. Immunization by multiple injections or by one injection plus streptomycin was superior to a single inoculation of organisms.