Non-acetylation of sulfanilamide during acquirement of drug resistance in Bacillus subtilis

Abstract

Cells of susceptible and sulfanilamide-resistant strains of Bacillus subtilis were harvested under various cultural conditions and examined for their ability, if any, to acetylate sulfanilamide. The effects of added acetate, citrate and accessory factors such as pantothenic acid and methionine were studied. Experiments were also carried out employing cells enriched with glucose, phosphate and pantothenic acid. The results showed no measurable acetylation of sulfanilamide in all cases. A diazotizable arylamine accumulated in the culture filtrates of 0·5 per cent. sulfanilamide-resistant strain, but not of the susceptible strain, during growth of the organism and even in the absence of added sulfanilamide. It is concluded that detoxification of sulfonamides through acetylation is not the mechanism of drug resistance in B. subtilis. There is also no adaptive enzyme formation for the detoxification or utilization of sulfanilamide during acquisition of drug resistance.