Mutations to Triple-Drug-Resistance in Double-Drug-Resistant Mycobacterium Tuberculosis

Abstract

The occurrence of double-drug-resistant Mycobacterium tuberculosis as strains simultaneously resistant to streptomycin and PAS or to isoniazid and PAS can be never or rare occurrence in patients who have received combined chemotherapy for pulmonary tuberculosis. The problem of triple-drug-resistance appears now very important in these patients having double- drug-resistant organisms. The present paper concerns this problem, i. e., the appearance rate of tirple-drug-resistant mutants in strains of M. tuberculosis simultaneously resistant to streptomycin and PAS or to isoniazid and PAS.

Mutation to triple-drug-resistance in strains simultaneously resistant to streptomycin and isoniazid has been previously studied by one of us¹⁾.