[Characteristics of Mycobacterium tuberculosis strains circulating in Pskov region].

AIM: Characteristics of drug resistance (DR) and population structure of Mycobacterium tuberculosis in Pskov region. MATERIALS AND METHODS: In 90 strains of M. tuberculosis drug resistance was studied by culture method and by using "TB-BIOCHIP"; genotyping was determined by spoligotyping method. RESULTS: 55 (61.1%) of 90 M.tuberculosis strains had drug resistance, with 40 (44.4%) being multi-resistant. M. tuberculosis population was presented by SIT1 spoligotype strains of genetic families Beijing--44.4%, LAM--21.1%, T--14.4%, Haarlem--11.1% and Ural--5.6%, according to SpolDB4. Among M. tuberculosis strains circulating in Pskov region the most widespread (44.4%) was SIT1 spoligotype (p < 0.0001). DR and multi-resistant DR (MDR) in Beijing strains occurred more frequently than in "non-Beijing" strains (p < 0.001 and p = 0.03 respectively) and were determined by rpoB mutations Ser531-->Ley and katG Ser315-->Thr. All the SIT252 spoligotype strains were multi-resistant, and their resistance to rifampicin was determined by rpoB Asp516-->Ser substitution, to isoniazid --katG Ser315-->Thr and inhA_T15 substitutions. CONCLUSION: The data obtained gives evidence on tuberculosis epidemiological unfavorability and wide circulation of MDR M. tuberculosis strains in Pskov region.