Staphylococcus aureus is a leading cause of foodborne illness in animal-derived food products, yet comprehensive data on its antimicrobial resistance and toxigenic potential from Central Asia remain scarce. We examined 711 food samples (meat, milk, and dairy products) from the Kostanay region of Kazakhstan (2024–2025). Isolates were identified by MALDI-TOF mass spectrometry; antimicrobial susceptibility was assessed by disk diffusion (EUCAST v.16.0); enterotoxin production (types A–E) by ELISA; and resistance and toxin genes by PCR. Concordance between methods was evaluated using Cohen’s kappa coefficient. S. aureus was recovered from 11.8% of samples (84/711), with raw cow’s milk carrying the highest contamination risk (OR = 2.75; 95% CI: 1.74–4.38). High resistance to ampicillin (52.4%) and benzylpenicillin (50.0%) was found; 20.2% of strains were multidrug-resistant. Among the 17 cefoxitin-resistant isolates, only 4 harbored mecA, suggesting that 13 isolates (15.5%) should be interpreted as cefoxitin-resistant, mecA-negative isolates with a putative BORSA-like phenotype rather than as confirmed MRSA. Staphylococcal enterotoxins A–E were detected in 26.2% of isolates, and egc-cluster genes seg and sei were present in 9.5% each. The strongest genotype–phenotype concordance was observed for aph(3′)/kanamycin (κ = 0.65) and blaZ/benzylpenicillin (κ = 0.64). These results underscore the need for combined molecular and phenotypic surveillance for regional food safety monitoring.

The widespread use of antibacterial agents in livestock production is associated with antibiotic residues in animal products and feed, posing a potential threat to food safety and contributing to antimicrobial resistance. The aim of this study was to assess contamination levels of beef, pork, and feed with antibiotic residues in the Kostanay region. The results demonstrated the presence of antibiotic residues in beef, pork, and feed, while all detected concentrations remained below established maximum residue limits. Despite compliance with regulatory standards, residues were detected frequently, and their levels differed significantly depending on feed type (p < 0.001). Microbiological analysis confirmed the presence of Escherichia coli and Staphylococcus aureus in meat samples, with isolates exhibiting moderate to high antimicrobial resistance, particularly in pork. The highest resistance was observed to tetracycline, streptomycin, and thiamphenicol. The obtained data indicate that even trace antibiotic concentrations entering the “feed–animal–product” chain may be associated with selective pressure on microbiota and the circulation of resistant microorganisms. The results highlight the need for comprehensive monitoring of feed and animal products to assess and mitigate antimicrobial resistance spread within the food chain.

The Kustanay horse is a riding breed developed in Kazakhstan whose genetic diversity and differentiation remain insufficiently studied. We assessed genetic diversity and population structure using 16 autosomal STR loci from a 17-locus panel comprising 12 ISAG core markers. Of 765 genotyped horses, 703 remained after excluding duplicate records and close relatives; the X-linked LEX3 locus was excluded from population analyses. Five groups were studied: registered Kustanay (KST, n = 32), Kustanay from Qazaq Tulpary (KT, n = 36), Thoroughbred (TB, n = 31), Kustanay crossbred (CROSS, n = 9), and undocumented origin (UB, n = 595). Expected heterozygosity was high across groups (H_E = 0.661–0.725). Overall F_ST was 0.0088, and AMOVA attributed 99.13% of molecular variance to variation within individuals. The Puechmaille estimators favored K = 2, whereas Evanno ΔK peaked at K = 4; neither solution revealed clear separation among groups. Nei’s genetic distances and PCoA were consistent with weak differentiation and similarity between registered Kustanay and undocumented horses. Unequal group sizes limit interpretation, and these findings do not establish breed identity for individual undocumented horses. The results inform pedigree recording and conservation planning.