ETHYLENE OXIDE STERILZATION OF SALMONELLA SENFTENBERG AND ESCHERICHIA COLI DEATH KINETICS AND MODE OF ACTION

Death of lyophilized Salmonella senftenberg and Escherichia coli when exposed to gaseous ethylene oxide (ETO) followed first order kinetics. S. senftenberg in whole egg powder was about twice as resistant as it was in the clean state. Supplementation of a minimal growth medium with amino acids, organic acids, the base components of DNA and RNA, vitamins and nucleic acid sugars demonstrated that guanine and guanosine triphosphate were the only supplements which would promote reproduction of cells surviving severe ETO treatment. Treatment of guanine and guanosine triphosphate with ETO prior to adding them to the minimal medium caused guanosine triphosphate, but not guanine, to lose he ability to promote reproduction, indicating that under the conditions of this experiment, only the guanosine triphosphate was alkylatable; and that, it was alkylation of this component of DNA that caused the bacterial cells to lose their power of reproduction.