STREPTOMYCIN RESISTANT TUBERCLE BACILLI - THEIR DEVELOPMENT DURING STREPTOMYCIN THERAPY OF PULMONARY TUBERCULOSIS

Abstract

Streptomycin sensitivity tests were performed on tubercle bacilli isolated from 20 streptomycin-treated patients. In 25% of the patients, tubercle bacilli were sensitive to streptomycin through 11 wks. of therapy, but throughout the remainder of the 120 days of therapy they developed varying degrees of streptomycin-resistance. These tests were performed in the Dubos-Davis tween-albumin medium. At the end of therapy, of 20 strains tested, in the Youmans median 55% were streptomycin-resistant; in the Dubos-Davis medium only 25% were resistant. Resistance to streptomycin was unchanged in 5 strains after 6 mos., suggesting that streptomycin resistance of tubercle bacilli is a perman. ently acquired characteristic.