مصطفی نعمتی

Introduction: Staphylococcus aureus is one of the most important pathogens in the milk industry. Considering that milk is a valuable food and provides an important part of the nutritional needs of society, it is very important to pay attention to the health issues of milk. This study aimed to investigate the presence of some pathogenic genes in Staphylococcus aureus strains isolated from dairy products in Kut, Iraq. Method: 100 samples of dairy products were collected from dairy stores in Kut city. Identification of Staphylococcus aureus involved the use of differential and biochemical tests. The isolates were distinguished based on cultural characteristics, Gram staining, coagulase, and DNase tests. The antibiotic resistance profile was determined using the disk diffusion method with Ciprofloxacin, Vancomycin, Cefazolin, Erythromycin, and Penicillin. The presence of bla Z, fem A, clfA, pvl, nucA and mecA genes, was examined using the PCR method. Results and Conclusion: Out of 100 collected milk product samples, 27 (27%) samples were shown the presence of Staphylococcus aureus. The isolates were confirmed as S. aureus by tracking the nucA gene. 4 isolates (14/82%) contained the ClfA gene, 7 isolates (25/93%) had the bla Z gene, 9 isolates (33/33%) had the fem A gene, and none of the isolates expressed the pvl gene. The highest presence of antibiotic resistance was related to Erythromycin and Cefazolin and the lowest was related to Vancomycin. As a result of the elevated levels of contamination in milk products in this study, the considerable resistance to antibiotics in raw milk poses a potential threat to consumer health. Consequently, identifying these strains and controlling sources of milk contamination should be integrated into the quality control standards for milk and dairy products.