[S and R forms of Mycobacterium tuberculosis as a problem of producing cloned and phenotypically competent strains].

The authors suggest that animals and humans carry M. tuberculosis in S form. These mycobacteria are virulent, do not form conglomerates and represent biologically most potent form. The state of R-form M. tuberculosis results from their culturing on artificial culture media which fail to secure compatible conditions for cells. M. tuberculosis S-form is convenient for microbiological and molecular-genetic research. The authors offer a method of biological production of single M. tuberculosis in S form.