Phylogenetics, evolution and phylogeography of Bacillus anthracis
Objective. Evolutionary and phylogeographical analysis of the strains of B. anthracis isolated from territories of Russia and some adjacent countries. Materials and methods. The full genomic sequences of 20 strains of B. anthracis sequenced in Stavropol Plague Control Research Institute and of 161 strains from the GenBank database. Multiple alignement of 181 B. anthracis strains' genomes and core genome SNP search were performed using REALPHY 1.10. program. For Baesian MCMC phylogenetic analysis of molecular sequences and General Time Reversible (GTR) model program pack BEAST was used. Estimation of analysis results and statistic reliability were performed using Tracer v1.6. program. Visualization of results by Figtree v1.4 (phylogenetic tree) and Photoshop CC programs was achieved. Results. The high molecular variety of strains isolated in Russia and some adjacent countries is confirmed. In phylogenetic structure of global population of B. anthracis those strains are mainly belonging to the trans-euroasian group and Aust94 subclade of the main clade of A and also forming a small cluster in a main B. The chronology of formation of the main phylogenetic lines of the causative agent of anthrax is established and the assumption of initial origin and distribution of B. anthracis from the territory of an Asian part of Russia is postulated for the first time. Conclusions. It is supposed to define further regional genetic markers which analysis in comparison to the corresponding database will give the chance during epidemiological investigation to establish origin of the strains which have caused the outbreak of anthrax.