Background and Aim: Staphylococcus aureus is the most frequent and ubiquitous cause of mastitis in cows. In recent decades, antibiotic resistance has rapidly spread among infectious disease pathogens in Kazakhstan and globally. This study examined the phenotypic and genotypic resistance of S. aureus strains obtained from cattle milk to antibiotics. Materials and Methods: In 2021 and 2022, 675 cow milk samples were collected from 16 dairy farms in Northern Kazakhstan. Staphylococcus aureus was identified using culture and biochemical methods. The nature of antibiotic resistance was determined by the disk diffusion (DD) method. The distribution of antibiotic resistance genes was determined by polymerase chain reaction. Results: Among the obtained S. aureus isolates, high levels of resistance to β-lactam antibiotics (100%), tetracyclines (95.4%), fluoroquinolones (95.4%), and macrolides (60.92%) were observed. Meanwhile, the lowest levels of resistance were identified for sulfonamides (21.84%) and aminoglycosides (27.59%). All the obtained isolates were positive for the nuc gene encoding thermonuclease. The blaZ, ermC, and tetK genes were detected in 45.9%, 77%, and 83.9% of the studied S. aureus isolates, respectively. Conclusion: The results indicate a high prevalence of antibiotic resistance in S. aureus isolated from cows with clinical and subclinical forms of mastitis in Northern Kazakhstan. In addition, the prevalence of resistance was higher when evaluated by the DD method than when detecting the specific antibiotic resistance genes blaZ, tetK, and ermC, indicating the need for deeper analysis of the phenotypic and genetic determinants of antibiotic resistance. Keywords: antibiotic resistance genes, cow milk, polymerase chain reaction, Staphylococcus aureus strains.

This article presents the findings of a scientific study investigating the efficacy of various assessment techniques used to evaluate the adaptability and productive qualities of Aberdeen Angus cattle on three prominent farms in the northern region of the Republic of Kazakhstan. A comprehensive analysis of the haematological and biochemical parameters of experimental groups of cattle with different genotypes (American, Canadian, and Estonian selection) was conducted. The studies revealed notable variability in haematological and biochemical indicators, contingent on the origin. Concurrently, the dynamics of the aforementioned indicators did not exceed the physiological norms. The modern allelofund was characterised with the help of microsatellite markers, and the level of genetic diversity of Aberdeen Angus cattle of different genotypes was estimated. The research uncovered the genealogical structure of the populations, the purity of the populations, the provenance, the polymorphism level, the heterozygosity indices, and the Wright fixation index (Fis). The genotyping of cattle of the Aberdeen Angus breed on 15 microsatellite markers yielded the establishment of 80 alleles in the Kolos-firm LLP, 77 alleles in the Vishnevskoe LLP, and 92 alleles in the Sever-Agro N LLP. The total expected heterozygosity was He = 0.673, while the observed heterozygosity was Ho = 0.710.

Background: A total of 396 samples were taken from the hearts, oesophagi, and diaphragms of 132 horses slaughtered at slaughterhouses in 2023 for subsequent examination. Methods: The histological method revealed pathomorphological changes in the muscle tissue. The molecular method identified the pathogen species. Results: Histological examination revealed thick-walled cysts with internal septa and numerous bradyzoites, and mononuclear inflammatory cells with pericyst infiltrates. Microcyst samples were amplified by polymerase chain reaction. Molecular genetic analysis allowed for the identification of 18 sarcocysts. Phylogenetic analysis of Sarcocystis isolates revealed three separate clades of Sarcocystis bertrami and two separate clades of Sarcocystis fayeri. Comparison and phylogenetic analysis revealed a very close relationship between the identified Sarcocystis species and other equine Sarcocystis DNA sequences from China and Japan. Based on the results obtained, the epizootic situation and the parasitic level of sarcocystosis contamination of horses in the northern Kazakhstan were determined. Conclusion: This is the first histological and molecular study to identify Sarcocystis spp. isolated from microscopic forms of equine sarcocysts in the northern Kazakhstan. This research will contribute to the fight against the spread of sarcocystosis in the Republic of Kazakhstan and will allow us to develop proposals for improving the mechanisms of sarcocystosis control.

Большую роль в наращивании производительности молочной отрасли играют не только технологии разведения и селекции крупного рогатого скота, но и применение современных методов молекулярно-генетического тестирования на наличие однонуклеотидных замен (SNP) в генах, оказывающих влияние на изучаемые признаки. К таким генам относится ген лектина, связывающего маннозу. Маннозосвязывающий лектин является важным компонентом врожденного иммунитета, участвуя в процессах опсонизации, активации комплемента и нейтрализации чужеродного агента. Ген лактоферрина, кодирующий многофункциональный металлосвязывающий белок, обладающий бактериостатической и бактерицидной функцией. Гены соматотропинового гормонального комплекса (гены гормона роста и инсулиноподобного фактора роста) играющие ключевую роль в развитии организма и метаболизме, от которого зависит качественный состав молока. Целью данного исследования явилось установление предпочтительных и нежелательных генотипов указанных генов, ассоциированных с показателями молочной продуктивности и качества молока среди поголовья черно-пестрой породы. Изучение, выявление и привлечение в селекционные программы по повышению молочной продуктивности и качества молока генетических маркеров может сделать значительный вклад в развитие отечественной селекции и ветеринарии.

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.

Ensuring the microbiological safety of meat and meat products is a crucial aspect of people's health protection, particularly in regions with developed livestock industries such as Kostanay region. In this area, meat production and processing are key sectors of the economy. However, contamination of meat products with enteropathogenic microorganisms such as Escherichia coli, Staphylococcus aureus, and Salmonella entericaposes a serious threat to human health by increasing the risk of foodborne toxicoinfections.The aim of this study was to conduct microbiological monitoring of meat and meat products sold in retail outlets across Kostanay region in order to assess the level of contamination with enteropathogenic bacteria. Using bacteriological and biochemical methods, a total of 279 samples of various meat types and products were collected and analyzed. From these, 84 bacterial isolates were identified: E. coli–59 isolates (70.2%), S. aureus–22 isolates (26.2%), and S. enterica–3 isolates (3.6%). The highest contamination rates were observed in poultry products (40.5%) and frozen semi-finished products (28.6%).These findings indicate significant gaps in compliance with sanitary and hygienic standards during the processing and storage of meat products. The presence of pathogenic bacteria represents a serious risk to public health, especially for vulnerable groups such as children, the elderly, and immunocompromised individuals. The results highlight the urgent need for regular microbiological monitoring and the implementation of effective measures to ensure food safety in the region.