Search

The paper reports the investigation of the population structure of Yersinia pestis strains belonging to the ulegeica subspecies (genetic branch 0.PE5), which is endemic to the natural plague foci in Mongolia and which is characterized by low epidemic potential compared to the strains belonging to the main plague subspecies. Whole genome SNP analysis of 12 Y. pestis subspecies ulegeica strains isolated in Mongolia considering the 1581 identified core SNPs revealed two main genetic clusters in correspondence with the geographic distribution of these strains. The first cluster, named 0.PE5/1, contains the strains isolated in the Umnegov', Uverkhangai, and Gov'-Altai aimaks located in the south of Mongolia. The second cluster 0.PE5/2 comprises two subclusters, namely, 0.PE5/2-1, containing the strains from the Bayan-Ulgii and Khovd aimaks, and 0.PE5/2-2, represented solely by the strains isolated in the Bayan-Ulgii aimak. To find the possible causes of the selective virulence of subspecies ulegeica strains, the analysis of the nucleotide sequences of 79 pathogenicity factors along with some other genomic regions has been carried out. Specific mutations have been found in the following genes: irp1, included in the high-pathogenicity island of the chromosomal pigmentation region, and yscQ, involved in the regulation of the synthesis of the LcrV protein and outer membrane proteins (Yops) associated with plague pathogen virulence. [ABSTRACT FROM AUTHOR]

The genetic diversity of Yersinia pestis strains from the Mongolian natural plague foci has been investigated. A total of 32 strains isolated from western, eastern, and central aimaks, as well as from the territory of the Gobi region, have been studied. Twenty-four strains belong to the main Y. pestis subspecies, while eight belong to non-main subspecies. There is only one strain of biovar medievalis (genovariant 2.MED1) among the strains of the main subspecies, while the rest of the subspecies belong to the biovar antiqua. Biovar antiqua strains are split into three groups. Strains from the eastern part of the country were classified as genovariant 2.ANT3, and those from the western and central regions were classified as genovariant 3.ANT2, which was endemic for Mongolia. One strain from the Bayan-Ulegeiskii aimak had the rare genovariant 4.ANT. None of the strains of the biovar antiqua belonged to its ancient 0.ANT branch, which is inconsistent with the commonly accepted idea that ancient marmot's plague agent race originates from Mongolia. Six out of eight strains of the non-main subspecies belonged to the ulegeica subspecies, which are endemic to Mongolia, one strain belonged to the microtus group, and the last belonged to a previously uncharacterized variant of the minor subspecies. [ABSTRACT FROM AUTHOR]