Methicillin-resistant Staphylococcus aureus (MRSA) strains have veterinary and public health importance as they are responsible for a wide range of difficult to treat infections and food poisoning. Two hundred samples (50 samples each of minced meat, beef luncheon, Karish cheese, and human samples (pus swab from open wounds)) were cultured, and MRSA strains were identified using disk diffusion tests and mecA gene-based PCR. A total of 35% (70/200) of the examined samples were confirmed as coagulase-positive S. aureus in minced meat (46%), beef luncheon (44%), Karish cheese (44%), and human samples (22%). The MRSA strains showed resistance to amoxicillin (91.4%), penicillin (97.1%), cefoxitin (85.7%), cephradine (82.9%), tetracycline (57.2%), and erythromycin (52.8%). More than half of the tested S. aureus isolates harbored the mecA gene. The sequence analysis of the mecA gene from the minced meat, Karish cheese, and human samples revealed high genetic similarities between the S. aureus isolates from these sources. In conclusion, our findings indicate a risk for the transmission of the mecA gene of S. aureus across the food chain between humans and animal food products. Further studies should focus on finding additional epidemiological aspects of the MRSA strains in food chain.
Use of phenolphthale in diphosphate agar with polymyxin as a selective medium for the isolation and enumeration of coagulase-positive staphylococci from foods.
