Characterization of molecular evolution in multi-drug resistant Mycobacterium tuberculosis in patients with active pulmonary tuberculosis of different regions in Belarus

This is the first genetic biodiversity study of M. tuberculosis in Belarus. Thus, we investigated the genetic patterns of strains isolated in the first survey of anti-tuberculosis drug-resistance realized by rpoB gene as part of the Global Project of Anti-tuberculosis Drug Resistance Surveillance (BRIEM, Belarus). A 411-bp fragment of the rpoB gene, containing the sequence of the 81-bp rpoB fragment, was amplified by PCR and the rpoB gene fragments of tuberculosis strains were sequenced using the Amersham auto sequencer. This method uses the variability of nucleic sequences of genes such as beta subunit RNA-ase (rpoB) internal transcribed spacer and other genes. For analysing tree evolution used method UPGMA and Neighbour-Joining and analyzed by MEGA program. Clinical isolates (44/463) were analyzed by using sequencing gene rpoB and genotyped by program MEGA. The results were compared with the international database. MDR was 35% in never treated patients and 13.5% in previously treated patients. Mutations in rpoB gene and katG genes were detected in 95% and 84% of the MDR strains, respectively. Two clusters were found to be identical by the four different analysis methods, presumably representing cases of recent transmission of MDR tuberculosis. This study gives a first overview of the M. tuberculosis strains circulating in Belarus during the first survey of anti-tuberculosis drug-resistance. It may aid in the creation of a national database that will be a valuable support for further studies.