RESUMO
AIM: Determination of critical concentration for chemotherapy drugs, widely used for tuberculosis treatment, for use in Mycobacterium tuberculosis drug sensitivity results evaluation by Sensititre MycoTB test-system. MATERIALS AND METHODS: Minimal inhibiting concentration (MIC) of isoniazid, rifampicin, streptomycin, ethambutol, amikacin, kanamycin, ofloxacin and moxifloxacin against conditionally sensitive and conditionally resistant strains of tuberculosis mycobacteria (TBM), isolated from various diagnostic material, obtained from patients with various forms of lung tuberculosis being treated in MCSPCTC hospital and dispensaries for tuberculosis control of Moscow, were studied in Sensititre MycoTB test system. RESULTS: Critical concentration of chemotherapy drugs for MycoTB test system was determined as a result of the obtained MIC values analysis as the minimal concentration that suppressed growth of 95% of sensitive strains and does not obstruct growth of 95% of resistant. The following MIC values were established: streptomycin--1.0, isoniazid--0.25, rifampicin--1.0, ethambutol--4.0, ofloxacin--2.0, moxifloxacin--0.25, kanamycin--2.5 and amikacin- 1.0 µg/ml. CONCLUSION: The developed critical concentration of the mentioned preparations is currently used for evaluation of sensitivity/ resistance of TBM clinical isolates from MCSPCTC.