Phylogenetic analysis of Bacillus anthracis strains from Western Siberia reveals a new genetic cluster in the global population of the species

Abstract

Background Anthrax is a zoonotic disease caused by the gram-positive bacterium Bacillus anthracis . The most anthrax-endemic regions of Russia are Siberia and North Caucasus. Previously, genotyping of Russian B.anthracis isolates was carried out using canSNP and MLVA data; these methods yield lower resolution results compared to whole genome SNP analysis (wgSNP). In this research, we have used wgSNP method for genotyping of 10 B.anthracis isolates, obtained during 1961–2016 in Russia on territory of Western Siberia. Results We have analyzed 185 B.anthracis genomes available in GenBank database and genomes of 10 isolates obtained in this study to determine the place of Russian isolates in the global phylogeny of B.anthracis . For the studied genomes we have detected 7203 SNPs, which were used for building a phylogenetic reconstruction with Maximum Likelihood Method. Results of the phylogenetic analysis indicate that Russian strains belong to three different genetic groups. Three strains belong to genetic group “Ames”, two strains – to “STI” group. Five strains belong to the main genetic line B, and four of them form a subcluster, described for the first time, which we have named “Siberia”. Conclusions In this study, the data on genetic diversity of B.anthracis strains on the territory of Western Siberia is presented for the first time. As a result of complex phylogenetic analysis, the place of these isolates was determined in the global phylogenetic structure of the B.anthracis population. We describe a new cluster in the main genetic line B for the first time. Electronic supplementary material The online version of this article (10.1186/s12864-019-6060-z) contains supplementary material, which is available to authorized users.

Sequence Variability of pXO1-Located Pathogenicity Genes of Bacillus anthracis Natural Strains of Different Geographic Origin

“…Moreover, we would like to focus on lineage B strains. Previously it was shown that B. anthracis strains of the B.Br.001/002 group circulating in Siberia form a separate phylogenetic cluster, named «Siberia» [38]. However, in our work two Siberian B.Br.001/002 strains were combined into one GT5 with the B.Br.CNEVA group, but not with other B.Br.001/002 strains, including not with the strain I-364 isolated in Siberia.…”

Variability of the Bacillus anthracis tryptophan operon

“…According to our data, the subclade B.Br.002 contains, along with the isolate from Korea, strains isolated in Western Siberia (a separate cluster "Siberia") and Finland [13], although in an earlier work the strain from Finland was described as constituting a separate clade line B.Br.002 with the nearest strains HYU01 from South Korea and BF1 from Germany [14]. Based on the data described, it can be assumed that clade C, the oldest, with a minimum number of isolates, has become a blind branch of the evolution, which has not received further distribution outside the United States.…”

Screening of possibly anthrax-contaminated burial sites in eastern and southern Ukraine

“…qPCR results have shown that the obtained isolate is a possible avirulent B. anthracis variant, but we still need to do further studies on the one isolate to be sure about. Isolation of pathogenic STI isolates in Caucasus, Yakutia and Western Siberia were reported by Pisarenko et al (2019). Moreover, both pXO1 and pXO2 plasmids may be lost long storage within ground waters and also under certain other environmental or laboratory conditions (Turnbull et al, 1992;Marston et al, 2005).…”