Induced Resistance to Streptomycin

Abstract
Summary: Some chromogenic bacteria and a group of salmonella strains were “trained” to high streptomycin resistance in vitro. A few equally resistant strains were recovered from streptomycin treated patients. Acquired resistance is accompanied by marked alteration of metabolic activities of the bacteria. Decreased rate of growth and of reducing intensity, changed fermentation of carbohydrates and protein derivatives (H2S production), loss of pigment formation of B. pyocyaneus, loss of animal pathogenicity in salmonellae are the main indications of a damaged enzymatic system. No streptomycin destroying qualities develop in resistant strains. It is suggested that induced resistance to streptomycin is not so much the result of a selective process but rather the physiological response of the bacterial cell against the damaging drug. The mode of drug action and clinical implications are discussed.