[Biological characteristics of rifampicin-resistant Mycobacterium tuberculosis].

Eleven rifampicin resistant variants were obtained in vitro from rifampicin sensitive strains of M. tuberculosis. It was shown that the in-vitro development of the resistance to rifampicin was of the one-stage phenomenon type. The study on the morphological, tinctorial and cultural properties, catalase activity, cord factor and toxicity showed their identity in the initial rifampicin sensitive strains and the rifampicin resistant variants. The virulence of the rifampicin resistant variants for albino rats and rabbits did not significantly change either.