The aim of the study was to clarify the boundaries of the Central Asian natural plague focus of Kazakhstan and the modern boundaries of the areal of the great gerbil (Rhombomys opimus) in order to improve epizootiological monitoring and increase the effectiveness of preventive (anti-epidemic) measures.Materials and methods. Data from the epizootiological monitoring of the great gerbil populations in 14 autonomous foci of the Central Asian desert natural plague focus in the Republic of Kazakhstan between 2010 and 2020 were used for the analysis. An epizootiologic survey of an area of 875350 km2 was carried out. When processing the data, epidemiological, epizootiological, statistical research methods, as well as GIS technologies were used.Results and discussion. An increase in the total area of the Central Asian desert natural plague focus of the Republic of Kazakhstan by 79710 km2 (9.98 %) has been established for the period of 1990–2020. It is noted that the change in the area of plague-enzootic territory was a consequence of the ever changing areal of the main carrier of plague pathogen – the great gerbil – under the influence of climatic and anthropogenic factors. The most significant changes were found in the southeastern part of the plague-enzootic territory, including those for the Betpakdala (50 %), Balkhash (34.3 %), Taukum (13.3 %) and Mojynkum (0.32 %) autonomous foci. The area of the Aryskum-Dariyalyktakyr autonomous focus decreased by 2100 km2 (4 %). In 2000–2002, new Alakol’sky and Ili intermountain autonomous foci with a total area of 26759 km2 were discovered. It is shown that due to the regression of the Aral Sea, the areal of the great girbil expanded and the area of the North Aral and Kyzylkum natural plague foci increased by 10500 km2 (29.2 %) and 560 km2 (0.4%), respectively. The areas of the Aral-Karakum and UralEmba desert autonomous foci, on the contrary, decreased by 2000 km2 (2.6 %) and 12300 km2 (17.6 %), respectively. Passportization and landscape-epizootiologic zoning of the territory of the Central Asian desert natural plague focus of the Republic of Kazakhstan has been completed.

The aim of the study was to improve epizootiological monitoring and increase the effectiveness of preventive (anti-epidemic) measures for camel plague control in Kazakhstan.Materials and methods. We used the data on epizootiological and epidemiological monitoring in natural plague foci of Kazakhstan, long-term measurements and indicators for the period of 2000–2020 of the anti-plague and veterinary services of the Republic for the analysis. To process the evidence, epidemiological, epizootiological, microbiological, and statistical research methods, as well as GIS technology were applied.Results and discussion. The number of camels has increased by 2.2 times in Kazakhstan over the past 20 years. Where there were 98.2 thousand heads in 2000, it amounted to 216.4 thousand heads in 2020. Over the past 10 years, 152 camels died of unknown causes in the focal area of the country, but laboratory tests for plague turned out negative. According to the hazard criteria, the territory of the country has been conditionally divided into three zones: five regions with a high degree of hazard with a total area of 953.15 sq. km, five regions with medium degree of hazard with a total area of 1230.72 sq. km, and with a low degree of hazard – four regions and three cities of republican significance with a total area of 541.1 sq. km. Constant epizootiological monitoring over plague in camels is a necessity for the system of preventive measures.

In the Central Asia desert natural focus of plague, the major carrier of the Yersinia pestis agent is the great gerbil Rhombomys opimus, and its vectors include fleas of the Xenopsylla genus. Phenotypical and genotypical properties of the R. opimus populations, Xenopsylla fleas and Yersinia pestis strains have been studied in the Central Asia desert natural focus of plague. Phenotypic distinctions and population discreteness have been identified in R. opimus on the cytochrome b gene of the mitochondrial genome from three autonomous plague foci: Pre-Balkhash, Betpakdala and Pre-Ustyurt. Phenotypic distinctions have been found in Xenopsylla fleas in the Central Asia desert natural focus of plague, and the genotype of X. gerbilli minax fleas on the Cox2 gene of the mitochondrial DNA; these had been captured in the Betpakdala autonomous focus. The repertoire diversity in phenotypical properties of Y. pestis strains from different natural foci of plague has been demonstrated, and population discreteness of Y. pestis strains has been determined using the next-generation sequencing method for single nucleotide polymorphism genes. Results of the study suggest that geographical and environmental isolation and natural selection have led to heterogeneity in the three populations of the great gerbil, vector fleas and Y. pestis.

This study explores the application of long-read sequencing technologies for genotyping, epigenetic profiling, and epidemiological monitoring of Yersinia pestis isolates obtained from natural foci in Central Asia and previous zoonotic outbreaks. Computational tools for genome assembly and genotyping were developed, enabling high-precision identification of both chromosomal and plasmid sequences, including the small cryptic pCKF plasmid. SNP-based genotyping distinguished the major Y. pestis biovars (Antiqua, Medievalis and non-main) and revealed cluster-specific diversity among Medievalis (MED) isolates, identifying a group of strains particularly prone to transmission from rodents to domestic animals and humans, which can be facilitated by the plasmid pCKF. Specific genomic polymorphisms were identified in sub-clades of MED isolates, which allow their identification with high precision. Additionally, comparative epigenomic analysis uncovered strain-specific cytosine methylation patterns at cg GATCG motifs, which may be linked to genome function regulation and adaptation to different hosts and environments. These findings demonstrate the effectiveness of long-read sequencing technologies in revealing both genetic and epigenetic features of bacterial pathogens, contributing to our understanding of the evolutionary mechanisms underlying the emergence and spread of this especially dangerous infection.

To ensure the biological safety of the country, it is necessary to develop priority areas of biotechnology, create advanced means of detecting pathogenic biological agents. Rickettsia bacteria, one of the most widespread zoonotic pathogens worldwide, continues to be a serious problem for public health. One of the solutions to the problems related to the situation of the effectiveness of rickettsiosis monitoring is the widespread introduction into clinical practice of modern diagnostic methods based on nucleic acid amplification (MANC) methods, in particular PCR. The paper presents the test results of experimental series of rickettsia detection kits. Purpose. Development and construction of experimental series of PCR test systems for the detection of rickettsioses, conducting control tests to work out optimal conditions in order to achieve maximum sensitivity and specificity of the drug.

This review provides a comprehensive overview of the genetic diversity and epidemiological potential of Yersinia pestis in Kazakhstan’s natural plague foci, emphasizing the link between genotypic variation and outbreak capacity. Integrating historical epidemiological records with contemporary microbiological and genomic data (including PCR, VNTR/MLVA, SNP analysis, and whole-genome sequencing), we evaluate core and accessory genome variations. The data reveal substantial regional heterogeneity. High-risk desert foci (Caspian and Aral regions) are dominated by the Medievalis biovar, including atypical genovariants lacking canonical markers. Conversely, high-mountain foci (Sarydzhaz, Talas) harbor the Antiqua and Talas biovars, primarily linked to enzootic circulation. Notably, the Ili River focus exhibits extreme genomic variability, featuring strains with plesiomorphic traits. Furthermore, the widespread distribution of mobile elements like the cryptic plasmid pCKF suggests significant horizontal transfer contributing to pathogen adaptation. Ultimately, Central Asian plague dynamics are driven by complex evolutionary and ecological interactions. Given climate change and expanding human–wildlife interfaces, continuous genomic and ecological surveillance is essential for the early detection of high-risk Y. pestis genovariants and improving public health preparedness.