Bactericidal Action of Streptomycin

Abstract

Summary

Streptomycin was bactericidal for both multiplying and non—multiplying cultures of K. pneumoniae, but not for washed spores of Bacillus sp. No. 290. Organisms surviving the bactericidal effect of 0.25 unit of streptomycin per ml after 6 hours incubation were more resistant to its action. This resis—tance persisted through 4 subcultures in the ab-sence of streptomycin and could be increased 5-fold by serial transfers in broth containing streptomycin. Washed organisms surviving after 5 hours incubation with 7.5 units of streptomycin per ml were not more resistant.