Staphylococcus aureus can cause foodborne poisoning and can form biofilms, reducing enterotoxin production and the penetration rate of antibiotics. Therefore, infections and poisonings caused by S. aureus can be difficult to treat. The aim of this study was to investigate the antibiotic resistance levels of S. aureus isolates obtained from raw milk and the presence of biofilm and mecA gene and to reveal the risk to public health. S. aureus was isolated in 30 (30%) of 100 raw milk samples obtained from Van province. A total of 48 S. aureus isolates were obtained from 30 samples. All 48 isolates (100%) obtained were resistant to penicillin G and cefoxitin, 4 (8.33%) to sulfamethoxazole-trimethoprim and chloramphenicol, and 25 (52.08%) to erythromycin. All of the isolates (100%) were found to be susceptible to ceftriaxone. In addition, 26 (54.16%) of the obtained isolates were found to be resistant to at least 3 antibiotics. The strains found to be resistant to penicillin and cefoxitin were also intermediate to at least one of the antibiotics. Biofilm genes were detected in 18 of the S. aureus isolates (37.5%). Twelve of the biofilm-forming isolates contain icaA (66.6%), 3 contain icaD (16.6%) and the other 3 contain bap genes (16.6%). Three of the isolates contain icaA and icaD genes and the other three isolates contain icaA and bap genes together. It was determined that only 2 of the isolates contained the mecA gene. The isolates containing the mecA gene also contained the icaA and icaD genes. In conclusion, the fact that S. aureus isolates had high antibiotic resistance, biofilm-forming genes, and methicillin resistance genes showed that raw milk may be a serious public health problem.

This study was conducted to investigate incidence of Toxoplasma gondii, Listeria monocytogenes and Staphylococcus aureus in 100 samples of salad and appetizers (50 salad and 50 appetizer samples) collected from retailers located various districts of Istanbul. Conventional microbiological methods and PCR procedures were used for Listeria monocytogenes and Staphylococcus aureus while only PCR procedures were used for the analysis of Toxoplasma gondii. Also PCR specifity and sensitivity for all the positive samples were calculated. According to the results, Listeria monocytogenes was detected in 9 samples (9%) and Staphylococcus aureus was detected in 36 (36%) samples while all the samples were negative for Toxoplasma gondii. PCR sensitivity results were quite specific and accurate for both Listeria monocytogenes and Staphylococcus aureus. It was concluded that salad and appetizers may be seriously threat consumers’ health microbiologically if they are processed under poor hygienic conditions.