Antibiotic Resistance, Biofilm Formation, and Molecular Epidemiology of Foodborne <i>Staphylococcus aureus</i> Isolated in Northwest Hubei Province, China

<i>Staphylococcus aureus</i> is a common pathogen responsible for foodborne infections worldwide. This study investigated the antibiotic resistance profiles, biofilm formation capacity, and molecular epidemiological characteristics of foodborne <i>S. aureus</i> isolates from northwest Hubei Province, China, as well as the correlation among these factors. Among the 303 food samples collected from Xiangyang, Suizhou, and Shiyan cities, 41 yielded non-duplicate <i>S. aureus</i> strains. Of the 41 <i>S. aureus</i> isolates, 8 (19.51%) were identified as MRSA, while 33 (80.49%) were methicillin-susceptible <i>S. aureus</i> (MSSA). High resistance was observed to penicillin (78.05%), tetracycline (43.90%), and erythromycin (31.71%), with MRSA strains demonstrating significantly stronger resistance profiles than MSSA strains. Among MRSA isolates, 50% (4/8) demonstrated strong biofilm-forming capacity, compared to only 9.09% (3/33) of MSSA isolates. Strong biofilm formation was observed more frequently in isolates from frozen meat (66.67%, 4/6) than in those from vegetarian salads (0%, 0/9) or fresh meat (12.50%, 2/16). The prevalence of Panton-Valentine leukocidin (PVL) gene was higher in MRSA strains, whereas enterotoxin genes were more commonly found in MSSA strains, though differences between groups were not statistically significant. The primary epidemic clones identified were CC88-ST88-t1376/t437, CC7-ST7-t091/t3884, and CC5-ST6/ST462-t701/t165, constituting 63.41% (26/41) of isolates. The CC59-ST59/338 strain exhibited a pronounced capacity for strong biofilm formation. SCCmecII-CC15-ST15-t085 and SCCmecIII-CC7-ST7-t3884 strains exhibited the highest antibiotic resistance, with resistance to 9 and 7 antibiotics, whereas CC88-ST88-t1376, CC7-ST7-t091, and CC5-ST6-t701 showed resistance to fewer than three antibiotics. The findings enhance the understanding of the drug resistance profiles and molecular epidemiology of foodborne <i>S. aureus</i>, providing a foundation for more effective control measures.