Phylogeorgaphy of Mycobacterium tuberculosis in central and border Mongolia

Abstract

The distribution of Mycobacterium tuberculosis and scope of tuberculosis morbidity in the world are extremely considerable. Among regions with high burden of tuberculosis (according to the World Health Organization data for 2015) Mongolia is one of the most disadvantaged countries. This research was continuation of studying of phylogenetic structure of M. tuberculosis for the determination of evolutionary and migration processes in pathogen's northeastern population and was devoted to the study of the spatial distribution of epidemically significant genotypes and subtypes, circulating in central and border (northern and southern) Mongolia. The DNAs of 309 clinical isolates of the pathogen were genotyped by the 24-locus MIRU-VNTR and LSP methods. Strains of the Beijing lineage were additionally analyzed for the presence of specific SNPs and its 24-MIRU-VNTR profiles were compared with reference database of M. Merker et al. (2015). The study indicated significant predominance of strains of the Beijing lineage (subtype CC4). This genotype is characterized by high frequency of clustering, which indicates its epidemic danger and the relatively recent introduction of «successful» strains into the territory of Mongolia. Also, a relatively homogeneous distribution structure of genotypes and subtypes of the pathogen was revealed within the studied region, which differs from the structure of the Russian population of M. tuberculosis by its subtypical composition. Thus, we assuming that CC4-strains of the Beijing lineage spread into Mongolia from neighboring East Asian regions, most likely from the Northern provinces of China (Inner Mongolia) or nearest neighboring countries of Southeast Asia.

Keywords

• mycobacterium tuberculosis
• miru-vntr
• mycobacterium tuberculosis
• miru-vntr
• beijing lineage
• phylogeography
• genetic diversity
• tuberculosis in mongolia