Authors : H. Mirzaei, A. Tofighi, H. Karimi Sarabi and Mahdi Farajli
Abstract: Recently Methicillin Resistant Staphylococcus aureus (MRSA) was isolated from dairy products in different countries. The aim of this study is to determine the prevalence rate of methicillin-resistant Staphylococcus aureus in raw milk, pasteurized milk, ice cream and traditional butter in Sarab by culture and PCR techniques. To do so, 200 samples of raw milk, pasteurized milk, ice cream and traditional cheese were collected from different sellers across Sarab. They were first evaluated for contamination by coagulase positive Staphylococcus aureus through culturing method and then, the isolates were subjected to PCR method according to nuc gene in order to confirm Staphylococcus aureus and methicillin resistance gene (mecA). The cultured samples indicated that 22 (44%) of raw milk samples, 4 (8%) of pasteurized milk samples, 9 (18%) of traditional butter samples and 12 (24%) of traditional cheese samples were contaminated by coagulase positive S. aureus. According to PCR using nuc gene primer, 18 (82%) of raw milk isolates, 4 (100%) of pasteurized milk isolates, 9 (75%) of traditional cheese isolates and 7 (78%) of traditional butter isolates contained nuc gene. According to PCR using MecA gene primer, 2 (50%) of pasteurized milk isolates and 2 (22%) of traditional cheese isolates contained MecA gene. No MecA gene was detected in raw milk and traditional butter isolates. The results provided evidence that the presence of coagulase positive Staphylococcus aureus and MRSA have become remarkably widespread in dairy product samples. This calls for better control of the sources of food contamination as well as the spread of antimicrobial-resistance organisms.
H. Mirzaei, A. Tofighi, H. Karimi Sarabi and Mahdi Farajli, 2011. Prevalence of Methicillin-Resistant Staphylococcus aureus in Raw Milk and Dairy Products in Sarab by Culture and PCR Techniques. Journal of Animal and Veterinary Advances, 10: 3107-3111.