Further Studies on the Testing of Sterility of Concentrated Streptomycin Solutions

Abstract

1. Further studies with semi-carbazide and hydroxylamine confirm earlier findings that for most of the bacterial species tested the former substance mol for mol is less bacteriostatic than the latter. 2. The use of either carbonyl reagent in sterility tests of concentrated streptomycin solutions, however, may lead to false negative findings. 3. Three strains of microörganisms have been isolated from streptomycin solutions which failed to grow out from similar material inactivated with either carbonyl reagent. 4. These organisms isolated from the streptomycin solutions grow poorly in thioglycolate broth, and one species was found to die out in this broth on incubation prolonged beyond 6 days. 5. The demonstration of psychrophilic organisms in streptomycin solutions suggests the need for incubating such sterility tests at more than one temperature.