Anthrax is a particularly dangerous infection of humans and ungulates caused by the Gram-positive spore-forming bacterium Bacillus anthracis. The highly monomorphic and clonal species B. anthracis is commonly divided into three main lineages, A, B, and C, which in turn are divided into several canSNP groups. We report here a phylogenetic analysis based on the whole-genome sequence (WGS) data of fifteen strains isolated predominantly in Siberia or Central and Southern Russia. We confirm the wide distribution of the cluster of strains of the B.Br.001/002 group, endemic to the Russian Arctic, which is also present in the steppe zone of Southern Siberia. We characterize additional branches within the major A.Br.001/002 polytomy comprising the A.Br.Ames and A.Br.Sterne lineages, one of which is identified in the Arctic.

The main pathogenic factor of Bacillus anthracis is a three-component toxin encoded by the pagA, lef, and cya genes, which are located on the pXO1 plasmid. The atxA gene, which encodes the primary regulator of pathogenicity factor expression, is located on the same plasmid. In this work, we evaluated the polymorphism of the pagA, lef, cya, and atxA genes for 85 B. anthracis strains from different evolutionary lineages and canSNP groups. We have found a strong correlation of 19 genotypes with the main evolutionary lineages, but the correlation with the canSNP group of the strain was not as strong. We have detected several genetic markers indicating the geographical origin of the strains, for example, their source from the steppe zone of the former USSR. We also found that strains of the B.Br.001/002 group caused an anthrax epidemic in Russia in 2016 and strains isolated during paleontological excavations in the Russian Arctic have the same genotype as the strains of the B.Br.CNEVA group circulating in Central Europe. This data could testify in favor of the genetic relationship of these two groups of strains and hypothesize the ways of distribution of their ancestral forms between Europe and the Arctic.

Climate change brings new risks of emergence of especially dangerous diseases. The paper reports the possibility of assessing the pathogenic potential of bacteria as demonstrated by studying the allelic polymorphism of anthrax bacterium pathogenicity factor genes, which is a prerequisite for assessing the associated microbiological risks. The allelic polymorphism of the capBCADE operon ( capB , capC , capA , capD , and capE genes) encoding the capsule biosynthesis proteins of Bacillus anthracis , and the acpA and acpB genes encoding the expression regulators of this operon have been studied for the first time. A number of single nucleotide polymorphisms (SNPs) were described in the strains of the studied sample, including 5 SNPs in the capB gene, 3 in capC , 4 in capA , 14 in capD , 2 in capE , and 15 in acpB , as well as 7 SNPs and one insertion in the acpA gene. As a result, the sample has been divided into sequence types for each gene and 17 genotypes, which are combinations of the identified sequence types. In silico translation of the detected alleles of the studied genes revealed three isoforms of the CapB and CapA proteins, two isoforms of the CapC and CapE proteins, six isoforms of the CapD protein, five isoforms of the AcpA protein, and four isoforms in the AcpB protein. It has been demonstrated that the SNP in the 351A → G position of capC is a marker of A.Br.Aust94 group strains. Based on the results, A.Br.Vollum group strains were divided into two subgroups. The strains in the evolutionary lines B and C differed from the line A strains by the presence of an 853G → A SNP in the acpA gene. In addition, a previously unknown variable number tandem repeat (VNTR), has been found in the acpA gene and the possibility of using it for differentiating and genotyping of B. anthracis strains has been demonstrated.

Anthrax is a particularly dangerous zooanthroponosis caused by the Gram-positive spore-forming bacterium Bacillus anthracis. This disease mainly affects hoofed herbivores, including those used in agriculture, but can occur in other animals and in humans. That is why the majority of studies of this infection are focused on anthrax in humans and farm animals, as the most important issues from a practical point of view. At the same time, the issues of anthrax epidemiology in natural ecosystems are described in the literature in insufficient detail and often very fragmentary. This paper provides a review of the literature describing the main pathways, patterns and risks of the spread of various clinical forms of anthrax infection in nature, primarily among wild animals. Among other things, we cover some non-notable aspects of intestinal infection with anthrax which, for instance, explain the difference in sensitivity to infection in herbivorous and carnivorous mammals and even different sex and age groups within the same species.

Strains of Bacillus genus were isolated from soil samples in the permafrost region (Yakutia, Russia). The phenotypic characteristics of the strains are given. The analysis of the obtained data made it possible to assign them to the Bacillus cereus complex. PCR analysis made it possible to determine the profile of B. cereus toxin synthesis genes in the genomes of the studied strains. Genetic characterization was obtained by RAPD genotyping and using MLVA loci used for genotyping of the anthrax pathogen. The results of genotyping at different levels of resolution made it possible to differentiate the studied strains from the B. anthracis species and to show their intraspecific genetic differences and the degree of relationship. Whole genome sequencing was carried out, based on the data of which MLST genotyping was carried out, which revealed two known sequence types and one new one that is described for the first time in this work. The results we obtained are of practical importance and are extremely interesting from the point of view of the evolution and phylogeography of the B. cereus group, since the fact that strains were isolated from permafrost suggests that their age may be much older than expected.

Objective – genotyping by multilocus sequence-typing (MLST) and phylogenetic analysis of 40 Bacillus anthracis strains isolated in Russia and neighboring countries.Materials and methods. In this study, the sequences of seven housekeeping genes of B. anthracis strains were assembled based on the data of a whole genome new generation sequencing, after which the identified mutations and their coordinates were described. The obtained sequences were used for genotyping of the investigated sample using the MLST method. The results are compared with the data presented in PubMLST database. A phylogenetic analysis was performed for the in silico fused sequences of the seven loci of the identified sequence types. The MEGA 7.0 software package was used to build the dendrograms.Results and discussion. Two sequence types (ST) have been found in the examined sample: 35 strains belong to ST-1, and five strains that differed by one common mutation at the glpF locus – to ST-3 (according to PubMLST coding), which emphasizes the genetic separation of this group of strains. One strain has a unique mutation in the gmk gene located outside the region used for MLST.