HYLOGEOGRAPHY OF THE BEIJING LINEAGE IN MONGOLIA

Abstract

Background. Mongolia is one of the seven countries in Western Pacific regions with high burden of tuberculosis. The earlier research indicates that there is a difference in the distribution of some epidemiologically important subtypes of the Beijing lineage in Mongolia and adjacent Russian regions. Aim of the research: assessment of genotypic structure of M. tuberculosis (MBT) on the border of Russia and central regions of Mongolia. Materials and methods: The DNAs of 143 clinical isolates of MBT from Russian border (46.2 %) and central (53.8 %) regions of Mongolia have been genotyped by the 24-locus MIRU-VNTR and RD105/RD207. Strains of the Beijing lineage have been analyzed additionally according to the classification by Merker et al. (2015). Results. The study of MBT in Mongolia indicates significant predominance of strains of the Beijing lineage (79.0 %) and Beijing MIT 17 subtype (72.6 %). However, the strains of the Beijing subtype W148, widespread in Irkutsk Oblast and Buryatia, have not been noted in Mongolia. According to the classification by M. Merker et al., the majority of studied strains of the Beijing lineage (85.8 %) relate to the clonal complexe CC4, infrequently detected in Russian border regions. Statistically significant differences between distribution of clonal complexes among border with Russia and central regions of Mongolia have not been detected. Conclusions. Strains of the clonal complex CC4 of Beijing lineage dominate in central and border to Russia regions of Mongolia, this allows assuming that the different geographical regions were sources of MBT strains, prevalent in Mongolia and adjacent Russian regions.