[Improvement of the microbiological diagnosis of tuberculosis with an account of the detection of L forms and ultrasmall mycobacteria].

Possible addition of various drugs to the Dorozhkova nutrient medium for isolation of L-forms of M. tuberculosis was studied with a purpose of preventing microbial contamination of the cultures. It was shown that the use of malachite green as 1% sterile aqueous solution in an amount of 11 ml per 1 liter of the medium lowered the number of the sprouts from 35 to 4.5 per cent. Various microscopic methods were tested to choose the most suitable one for isolating L-forms of M. tuberculosis. Different nutrient media for additional cultivation and isolation of revertants from ultrasmall mycobacteria were compared. The Dorozhkova medium provided reversion of the ultrasmall mycobacterial L-forms in 12 per cent of the cases. The respective index on the routine Sauton and Shkolnikova media amounted to 5 per cent.