Abstract
<jats:p>This article examines the degree of contamination of milk and dairy products of Kostanay region by antibiotic-resistant microorganisms. At the stage of subclinical mastitis, 321 samples of raw milk from dairy cows and 66 samples of dairy products from retail outlets (sour cream, cottage cheese, butter, cheese, cream, yogurt) were taken from dairy farms. A total of 143 strains of opportunistic bacteria were isolated and identified. Including from raw milk – 99 strains: S. aureus – 32, E. coli – 35, Str. agalactiae – 21, Proteus mirabilis – 7, Listeria monocytogenes – 4. From dairy products, 9 strains of S. aureus and 3 strains of E. coli were isolated from sour cream; 4 strains of E. coli from hard and soft cheese; 1 strain of E. coli and 1 strain of S. aureus from butter; 22 strains of S. aureus and 4 strains of Str. agalactiae from koumiss. All S. aureus strains (n=64) demonstrated resistance to at least one antimicrobial drug. The highest resistance was found to beta-lactam antibiotics, in particular ampicillin (42%), amoxicillin (39%), benzylpenicillin (35%), as well as kanamycin (37%), cefoperazone (32%), neomycin (31%) and tetracycline (29%). These indicators indicate the formation of multidrug resistance among staphylococci. Among E. coli strains (n=43), the highest resistance was registered to amoxicillin (32.5%), streptomycin (27.9%), gentamicin (23.2%), imipenem and kanamycin (20.9% each), as well as to nalidixic acid (18.6%). This indicates the high adaptability of E. coli to broad-spectrum antibiotics. Among Str. agalactiae strains (n=25), the greatest resistance was found to benzylpenicillin (52%), as well as to norfloxacin and erythromycin (28% each), tetracycline (20%) and vancomycin (12%). The high level of resistance to benzylpenicillin is of particular concern, as this drug is one of the main treatments for streptococcal infections. The data obtained indicate the need for systemic microbiological monitoring, optimization of the use of antimicrobials in dairy farming, and strengthening sanitary and veterinary control to ensure consumer safety.</jats:p>