This article describes Bacillus anthracis strains isolated during an outbreak of anthrax on the Yamal Peninsula in the summer of 2016 and independently in Yakutia in 2015. A common feature of these strains is their conservation in permafrost, from which they were extracted either due to the thawing of permafrost (Yamal strains) or as the result of paleontological excavations (Yakut strains). All strains isolated on the Yamal share an identical genotype belonging to lineage B.Br.001/002, pointing to a common source of infection in a territory over 250 km in length. In contrast, during the excavations in Yakutia, three genetically different strains were recovered from a single pit. One strain belongs to B.Br.001/002, and whole genome sequence analysis showed that it is most closely related to the Yamal strains in spite of the remoteness of Yamal from Yakutia. The two other strains contribute to two different branches of A.Br.008/011, one of the remarkable polytomies described so far in the B . anthracis species. The geographic distribution of the strains belonging to A.Br.008/011 is suggesting that the polytomy emerged in the thirteenth century, in combination with the constitution of a unified Mongol empire extending from China to Eastern Europe. We propose an evolutionary model for B . anthracis recent evolution in which the B lineage spread throughout Eurasia and was subsequently replaced by the A lineage except in some geographically isolated areas.

A knockout mutant with a deletion in a quorum sensing system gene qseC was generated from the vaccine strain Francisella tularensis 15 by site-directed mutagenesis. The variant with the inactivated gene qseC differed from the parental strain in growth rate on solid nutrient medium but had the same growth dynamics in liquid nutrient medium. The mutation abolished almost completely the resistance of the vaccine strain to normal rabbit serum and its ability to survive in macrophages; in addition, the strain lost the residual virulence. A significant phenotypic alteration was observed in the lipopolysaccharide of F. tularensis. Particularly, the mutant strain synthesized no noticeable amount of the lipopolysaccharide with the high-molecular-mass O-polysaccharide, presumably as a result of impairing biosynthesis of the repeating unit, namely, a loss of the ability to incorporate a formyl group, an N-acyl substituent of 4-amino-4,6-dideoxy-D-glucose.

20This article describes Bacillus anthracis strains isolated during an outbreak of anthrax on 21 the Yamal Peninsula in the summer of 2016 and independently in Yakutia in 2015. A common 22 feature of these strains is their conservation in permafrost, from which they were extracted either 23 due to the thawing of permafrost (Yamal strains) or as the result of paleontological excavations 24 (Yakut strains). All strains isolated on the Yamal share an identical genotype belonging to lineage 2 25 B.Br.001/002, pointing to a common source of infection in a territory over 250 km in length. In 26 contrast, during the excavations in Yakutia, three genetically different strains were recovered from 27 a single pit. One strain belongs to B.Br.001/002, as the Yamal strains. Despite the remoteness of 28 Yamal from Yakutia, whole genome sequence analysis showed that the B.Br.001/002 strains are 29 very closely related. The two other strains contribute to two different branches of A.Br.008/011, 30 one of the remarkable polytomies described so far in B. anthracis population. The geographic 31 distribution of the strains belonging to this polytomy is suggesting that this polytomy emerged in 32 the thirteenth century, in combination with the constitution of a unified Mongol empire extending 33 from China to Eastern Europe. We propose an evolutionary model for B. anthracis recent evolution 34 in which the B lineage spread throughout Eurasia and was subsequently replaced by the A lineage 35 except in some geographically isolated areas.36

Within the frames of activities attributed to the Reference Center for tularemia monitoring at SRC AMB, genetically identified are 4 isolates of Francisella tularensis, isolated in 2011 in the Altai Territory. These bacteria prove to be virulent for BALB/c mice, DCL being lower than 10 CFU. Using single-primer PCR-typing and MLVA assay distinguished have been the subspecies of the isolates. Three of them refer to the Central Asian subspecies, one-to the Holarctic, the former being isolated in the territory of the Russian Federation for the first time ever.

We report the draft genome sequences of three Francisella tularensis subsp. mediasiatica strains isolated in the Altai Territory, Russian Federation.