Modern Diagnostic Technologies in the Study of the Field Material Collected from the Natural Plague Foci of the Kyrgyz Republic in 2023

Abstract

The aim of the work was to analyze the results of investigating the field material obtained from natural plague foci of the Kyrgyz Republic (KR) in 2023, using modern diagnostic technologies.Materials and methods. 1435 biological samples from the Tien Shan, Alai and Talas high-mountain foci of the Kyrgyz Republic were studied using conventional methods of laboratory diagnosis of plague: microbiological, immunological, biological; as well as modern molecular-genetic methods. Testing of the obtained samples for the presence of plague pathogen DNA was carried out using RT-PCR; and the presence of antibodies to the plague microbe was detected by enzyme-linked immunosorbent assay (ELISA). Molecular identification of Yersinia pestis strains according to their appurtenance to subspecies, biovars, and phylogenetic lineages was performed by RT-PCR using the method of identifying single-nucleotide substitutions based on the analysis of melting curves of products.Results and discussion. An approach to the molecular identification of Y. pestis strains from plague foci of the KR has been developed and validated through identifying singlenucleotide substitutions using the analysis of product melting curves (HMR-analysis) with a set of designed primers. It has been established that Y. pestis strains isolated in the Sarydzhaz autonomous focus of the Tien Shan high-mountain focus belong to the biovar antiqua of the main subspecies, phylogenetic branch 0.ANT5. The phylogenetic relation of Y. pestis strains isolated in 2023 was studied based on genome-wide SNP analysis. Areas of epizootic activity in Eastern Alai have been identified. The data obtained indicate the sustained activation of plague foci in the KR. Areas of the territory of the KR that are promising for paleogenomic research are also discussed.