Occurrence and Integrated Food-Safety Characterization of Staphylococcus aureus in Retail Raw Meat from Northern Xinjiang, China

In this study, 327 retail raw meat samples collected from five cities were examined for Staphylococcus aureus , and 92 isolates recovered from 73 positive samples were further characterized for classical enterotoxin genes and toxin production, antimicrobial susceptibility, biofilm formation, and molecular typing. S. aureus was detected in 22.3% of samples (73/327), with positivity varying across the sampled cities and meat types. Classical enterotoxin genes were detected in 10.9% of isolates (10/92), and 9 of the 10 gene-positive isolates produced at least one detectable classical enterotoxin. Resistance was highest to penicillin (94.6%), erythromycin (71.7%), tetracycline (59.8%), and clindamycin (58.7%); 80.4% of isolates were multidrug-resistant, and 19.6% carried the mecA gene. Moderate or strong biofilm formation was observed in 93.5% of isolates. Among a purposively selected subset of 41 isolates used for molecular typing, spa type t236 and pulsed-field gel electrophoresis cluster P2 were the most frequently observed profiles. Overall, retail raw meat sampled in Northern Xinjiang harbored S. aureus with confirmed toxigenic potential in a subset, frequent multidrug resistance, and widespread biofilm-forming ability. Together, these results provide an integrated evidence base for prioritizing antimicrobial resistance and toxin surveillance alongside hygiene control in retail meat systems.