Background and Aim: Salmonella is one of the main causative agents of foodborne infections. The source of the pathogen, in most cases, is poultry products. The intensification of poultry farming and the constant and uncontrolled use of antimicrobials has led to an increase in the level of antibiotic resistance, especially in developing countries. This study aimed to determine the level of sensitivity to antimicrobial agents in Salmonella enterica strains isolated from poultry products in Northern Kazakhstan, as well as to determine the genetic mechanisms of resistance and the presence of integrons. Materials and Methods: In total, 398 samples of poultry products sold in Northern Kazakhstan were selected. Salmonella strains were isolated from product samples using microbiological methods. Salmonella was identified based on morphological, biochemical, and serological methods, as well as polymerase chain reaction (PCR). Sensitivity testing for antimicrobial agents was performed using the disk diffusion method. The detection of resistance genes was performed using PCR and gel electrophoresis. Results: Out of 398 samples of poultry products, a total of 46 Salmonella isolates were obtained. Most of the isolates belong to the serovar Salmonella Enteritidis (80.4%). The assessment of sensitivity to antibacterial agents showed that Salmonella was mainly resistant to nalidixic acid (63%), furadonin (60.9%), ofloxacin (45.6%), and tetracycline (39.1%). In 64.3% of cases, Salmonella was resistant to three or more groups of antibacterial agents. Resistance genes such as tetA, tetB, blaTEM, aadA, sul3, and catII, as well as integrons of two classes (teg1 and teg2), were identified. Conclusion: Poultry products contain antimicrobial-resistant strains of Salmonella, as well as genes encoding resistance mechanisms. The results emphasize the need for constant monitoring of not only pathogenic microorganisms but also their sensitivity to antimicrobial agents. The potential threat to human health requires a unified approach to the problem of antibiotic resistance from representatives of both public health and the agroindustrial complex. Keywords: antibiotic resistance, food safety, poultry, resistance genes, Salmonella.

Background and Aim: Escherichia coli, a commensal intestine bacterium of vertebrates, is widely distributed in the environment and indicates the microbiological quality of food products in relation to coliforms. In addition, virulent strains, particularly E. coli O157:H7, cause outbreaks of toxic infections caused by consuming dairy products. Because food safety studies regarding E. coli have not been conducted in Central Asia, this research aimed to study the characteristics of contamination, microbiological and genotypic properties, and resistance to antimicrobial agents of E. coli strains that contaminate various types of commercialized cheeses originating from Kazakhstan. Materials and Methods: In retail outlets, 207 samples of three types of cheese produced by 22 industrial and eight small enterprises in the central, eastern, southern, and northern regions of Kazakhstan were selected in 2020–2023. E. coli contamination was examined using standard microbiological, mass spectrometric, and molecular genetic methods. The discodiffuse European Committee on Antimicrobial Susceptibility Testing method was used to test the resistance of the identified E. coli isolates (65/207; 31.4%) to 20 antibacterial drugs. The Shiga toxin-producing E. coli (VT1 and VT2) and E. coli O157:H7 (eae) genes were investigated in all E. coli isolates using multiplex polymerase chain reaction. Results: An average of 31.4% samples of commercial Kazakhstani cheeses of various types were found to be contaminated with E. coli in almost all geographical regions of Kazakhstan, regardless of the productivity of the dairy enterprises. Soft cheeses produced by small farms (80% of samples) packaged at the retail site (100%) were the most contaminated with E. coli. The microbiological index (colony-forming unit/g) was unsatisfactory and unsuitable in 6.2% of such cheese samples. For the first time in Central Asia, the enteropathogenic strain E. coli O157:H7 was detected in 0.5% of cheese samples. E. coli isolates from cheese samples were resistant to 65% of antibacterial drugs and contained resistance genes to β-lactams, sulfonamides, and quinolones groups. At the same time, 25% of the E. coli isolates were multi-resistant to three or more antimicrobial agents. Conclusion: The high level of contamination caused by multi-antibiotic resistant E. coli strains, including pathogenic pathogens, poses a risk to public health and highlights the need for further research on the monitoring and control of coliform enteropathogens in food products. Keywords: antibiotic resistance, Escherichia coli O157:H7, Kazakhstan cheese, microbial contamination.

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.

The widespread use of antimicrobial agents for pets in veterinary practice has led to the emergence and spread of drug resistance not only in pathogenic but also in opportunistic bacteria. The study aims to evaluate the profile of resistance to antibacterial agents in Escherichia coli strains isolated from domestic cats and dogs, as well as to look into the determinants of resistance responsible for the ability of microorganisms to resist the effects of antimicrobial agents. During 2021-2022, biological material from cats and dogs, taken in veterinary clinics of Kostanay, Republic of Kazakhstan, was analyzed. Identification of genes encoding antimicrobial resistance was carried out by Polymerase Chain Reaction (PCR). As a result, it was found that all isolated strains of microorganisms showed sensitivity to the action of meropenem included in the group of beta-lactam antibiotics and showed resistance to tetracycline, doxycycline, ofloxacin, ampicillin, and amoxicillin. Resistance genes were identified for all the studied groups of antibiotics in the DNA of E. coli isolated from cats and no genes encoding resistance to fluoroquinolones were detected in the DNA of strains isolated from dogs. The most common genes were genes encoding resistance to aminoglycosides (43.8%), tetracyclines (35%), beta-lactams (33.5%), sulfonamides (16.1%), and fluoroquinolones (1.24%). In general, domestic cats and dogs have a high prevalence of E. coli strains resistant to beta-lactam drugs (ampicillin: 40%, amoxicillin: 36%) and tetracyclines (tetracycline: 71%, doxycycline: 47%). Resistance in most cases was explained by the presence of such resistance genes as blaTEM, OXA, tetA, and tetB.