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.

Salmonella enterica is a major cause of foodborne and invasive infections worldwide. This retrospective study used whole-genome sequencing to compare the genotypes and characterize the genomic diversity of bacterial strains preserved in an archived culture collection, originating from clinical and veterinary sources and predominantly from Kazakhstan. Twenty-two bacterial isolates were analyzed by Illumina whole-genome sequencing; subsequent characterization confirmed twenty as S. enterica and identified two as Escherichia coli. Six selected S. enterica strains representing different lineages were additionally sequenced using PacBio Revio SMRT technology for DNA methylation profiling. Genome assembly, plasmid reconstruction, MLST genotyping, and analyses of virulence genes, antimicrobial resistance determinants, restriction-modification (R-M) operons, and orphan methyltransferases were performed. Comparative genomic analysis revealed substantial genotypic diversity within the collection, while phylogenetic grouping was consistent with MLST classification. ST11 was the most represented sequence type among the selected strains, comprising 11 of the 20 S. enterica isolates, including all three recent clinical S. enterica isolates. All six PacBio-sequenced genomes showed >99% DAM-associated adenine methylation at GATC motifs, while DCM-mediated cytosine methylation occurred at approximately 35% of CCWGG motifs. Adenine methylation at CAGAG is controlled by additional type III R-M systems. Strain 19S showed a distinct type I-associated adenine methylation pattern together with several HsdM amino acid substitutions; however, the functional relationship between these observations requires experimental validation. The study demonstrates the value of retrospective genomic characterization of culture collections for revealing genetic and epigenetic diversity preserved among historical and recent bacterial isolates and provides a basis for future population-level and functional studies.

Topical semisolid formulations based on biopolymers and plant-derived components have attracted increasing attention for wound healing applications. However, their physicochemical stability and biological performance are strongly influenced by formulation composition and structural organization, which necessitates further systematic investigation. The aim of this study was to develop and optimize oil-in-water cream formulations based on biopolymer systems containing chitosan, xanthan gum, and plant extracts of Hypericum perforatum and Calendula officinalis. The formulations were prepared using a conventional emulsification method and evaluated in terms of pH, viscosity, rheological behavior, microbiological purity, and antimicrobial activity. Initial systems exhibited low viscosity and insufficient structural stability, which were improved by the incorporation of xanthan gum as a stabilizer. The optimized formulations demonstrated non-Newtonian shear-thinning behavior and pH values of 6.35 ± 0.08, indicating suitability for topical application. Formulations containing plant extracts did not exhibit antimicrobial activity against Staphylococcus aureus ATCC 6538 and Pseudomonas aeruginosa ATCC 9027. In contrast, the formulation containing naringin demonstrated selective bactericidal activity against Staphylococcus aureus up to a dilution of 1:16, with no effect observed against Pseudomonas aeruginosa. Overall, the developed systems showed appropriate physicochemical and rheological properties for dermal application. The study demonstrates that physicochemical optimization does not necessarily correlate with antimicrobial performance, highlighting the importance of formulation composition.

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 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.

Background Human enteroviruses are among the most common viral pathogens and are responsible for a broad spectrum of diseases ranging from mild febrile illness to severe neurological and systemic infections. Rapid and reliable laboratory diagnosis is essential for appropriate patient management and effective epidemiological surveillance. The aim of this study was to develop and perform a preliminary analytical validation of a novel real-time reverse transcription polymerase chain reaction (real-time RT-PCR) assay for the detection of human enteroviruses. Methods A highly conserved region within the 5′-untranslated region (5′-UTR) of the enterovirus genome was selected as the molecular target. Primers and a TaqMan hydrolysis probe were designed based on bioinformatic analysis of publicly available nucleotide sequences. The analytical performance of the assay was evaluated using serial dilutions of a synthetic positive control, assessment of analytical specificity against a panel of non-target viral and bacterial pathogens, and testing of clinical stool specimens collected from pediatric patients with suspected enterovirus infection. Results The developed assay successfully detected enteroviral RNA over a wide concentration range, with a limit of detection of 100 fg/µL. The standard curve demonstrated excellent linearity (R² = 0.997), a slope of − 3.77, and an amplification efficiency of 84.3%. No cross-reactivity was observed with West Nile virus, Crimean–Congo hemorrhagic fever virus, hemorrhagic fever with renal syndrome virus, tick-borne encephalitis virus, Rickettsia spp., Shigella flexneri , Salmonella enterica serovar Typhimurium, or Yersinia enterocolitica . Among 126 clinical stool specimens, enteroviral RNA was detected in 37 (29.4%) samples. Conclusions The developed real-time RT-PCR assay demonstrated high analytical specificity, satisfactory analytical sensitivity, and reliable performance in clinical specimens. The results indicate that the assay represents a promising domestic molecular diagnostic tool for the routine detection of human enteroviruses and has the potential to strengthen laboratory diagnostics and epidemiological surveillance of enterovirus infections in the Republic of Kazakhstan.