[Study of the drug-sensitivity of nontuberculous mycobacteria].

The central bacteriological laboratory of the Moscow Research-and-Practical Center for Tuberculosis Control studied the sensitivity of nontuberculous mycobacteria (NTM) to a number of antituberculous drugs (streptomycin, isoniazid, rifampicin, ethambutol, kanamycin, ethionamide, cycloserine, ofloxacin) by the absolute concentration method (after isolating the cultures on both solid and liquid nutrient media). A total of 160 cultures, including M. chelonae (n = 4), M. flavescense (n = 6), M. fortuitum (n = 34), M. avium complex (MAC) (n = 52), M. xenopi (n = 18), M. kansasii (n = 41), M. marinum (n = 2), M. malmoense (n = 1), M. simiae (n = 1), and M. gastri (n = 1), were explored. MAC was found to be resistant to streptomycin, isoniazid, rifampicin, ethambutol, and ethionamide in most cases, to ofloxacin in a nearly half of cases, to canamycin and cycloserine in a third of cases. In most cases, M. kansasii was sensitive not only to first-, but also second-line chemical drugs. M. xenopi was resistant to rifampicin in two thirds of cases and to streptomycin, isoniazid, ethambutol, and ethionamide in a half of cases. This species of NTM was more sensitive to kanamycin, cycloserine, and oflaxacin. In the majority of cases, M. fortuitum was resistant to streptomycin, isoniazid, rifampicin, ethambutol, ethionamide, kanamycin, and cycloserine and sensitive to ofloxacin.