Biological properties and molecular and genetic characteristics of plague microbe strains circulating in sandy natural plague foci of the Republic of Kazakhstan

Abstract

Since 2010, an active course of epizootics with the release of the plague pathogen, isolated from hosts and vectors has been established in 8 autonomous foci of the plague from 14 autonomous foci of the Central Asian plague focus in Kazakhstan. It was necessary to take into account the parameters of variability of the main component of the parasitic system – the plague microbe in the process of certification of landscape and epizootological zoning of natural foci of plague in Kazakhstan. The aim of the work was to study the phenotypic and genetic properties of strains of the plague microbe isolated in natural sandy plague foci of Kazakhstan. Materials and methods. The work used 1196 strains of Yersinia pestis isolated over the past 10 years (2010–2019) from natural sandy plague foci, strain passports, literature sources, data on certification of plague foci in Kazakhstan. The study of the strains was carried out by bacteriological, serological and molecular genetic methods. Results. Certification and typification of the territories of sandy plague foci were carried out, taking into account the phenotypic and molecular-genetic properties of Y. pestis strains isolated from 12 autonomous foci of the Central Asian plague focus of Kazakhstan in 2010–2019. According to the results of the study, 84 atypical strains were identified. As a result of the analysis, 18 genotypes were identified among the studied strains, of which 13 (72.2%) were unique and did not repeat in the sample. The remaining 5 genotypes formed 5 clusters, combining 20 strains (60.6%) and all strains were phylogenetically assigned to representatives of the Mediaevalis biovar. Key words: plague microbe, plague foci, phenotypic features, molecular genetic features