The Beijing genotype dominates the multidrug-resistant Mycobacterium tuberculosis population in North-West Russia

The occurrence of multidrug-resistant tuberculosis (MDR-TB) in a new TB patient reflects the MDR-TB spreading in a community. We aimed to perform molecular characterization of M. tuberculosis MDR strains from newly diagnosed TB patients in North-West Russia regions. A total of 586 M. tuberculosis isolates were studied. Beijing genotype and its main subtypes B0/W148 and Central-Asian/Russian were determined by PCR testing of specific markers and 24 MIRU-VNTR loci typing. Non-Beijing isolates were spoligotyped and compared to the SITVIT2 database. MDR was detected in 32.6% (191/586) isolates. The majority of MDR strains belonged to the Beijing genotype (83.8%; 160/191). The Beijing genotype was significantly associated with MDR (49.2%; 160/325) compared to the non-Beijing genotypes (11.9%; 31/261) (P < 0.0001). Of the 160 MDR Beijing strains, 152 (95.0%) belonged to its modern sublineage. The main Beijing clusters were B0/W148 – 43.1% (69/160) and Central-Asian/Russian – 46.3% (74/160). The largest Beijing Mlva clusters were 100-32 (50) and 94-32 (35). The 31 MDR non-Beijing isolates represented LAM (12), T (5), Ural (7), Haarlem (3), and “unknown” (4) families. The most common spoligotypes were SIT262/Ural (6), SIT42/LAM (5), and SIT266/LAM (3). In conclusion, the expansion of the M. tuberculosis MDR population in North-West Russia is dominated by the Beijing genotype family (83.8%), with B0/W148 and Central-Asian/Russian clusters presented in comparable proportions. This study was supported by Russian Science Foundation (grant 19-15-00028). We thank colleagues from regional TB dispensaries for providing bacterial strains.