Molecular Characterization of Virulence Genes in Coagulase-Positive Staphylococcus aureus Recovered from Restaurant Samples

Background: Staphylococcus aureus is one of the most severe foodborne pathogens which transmitted through contaminated food. Outbreaks of foodborne illnesses have been linked to animal-derived products, produce food poisoning a significant global public health concern. Objectives: This study aimed to isolate and identify Staphylococcus aureus using both classical and molecular techniques from different food sources in Baghdad. to detect genes encoding virulence factors for isolates collected different locations across the city different between June and September 2025. Methodology: A total of 340 samples were collected from meat, workers' hands, and equipment. Classical microbiological methods were employed for bacterial isolation, while molecular techniques—specifically PCR—were used to confirm the presence of virulence genes, including nuc, coa, clfA, clfB, sea, and seb. Results: The investigation revealed a prevalence rate of S. aureus of 46.47% (150/340). All S. aureus isolates carried the nuc and coa genes (100%, 34/34). The clfA gene was detected in 94.1% (32/34) and clfB in 91.2% (31/34) of the isolates. Additionally, the sea gene was present in 79.1% (27/34), while the seb gene was detected in 14.7% (5/34). Based on genetic profiling, S. aureus isolates were categorized into four major groups: Profile I (14.7%), Profile II (64.7%), Profile III (8.8%), and Profile IV (2.9%). Conclusion: The high prevalence of Staphylococcus aureus in meat, tools, and workers' hands highlights the significant role of restaurants and food processing environments in the dissemination of foodborne pathogens. The detection of multiple virulence genes—especially using PCR—underscores the high pathogenic potential of these isolates and reinforces the need for strict hygiene and food safety practices to prevent the spread of foodborne infections.