Prevalence of Staphylococcus aureus in imported fish and correlations between antibiotic resistance and enterotoxigenicity

Abstract

A total of 156 Staphylococcus aureus isolates were obtained from 330 imported fresh fish samples from three countries. Selective media were used for the isolation of S. aureus, and the isolates were confirmed by PCR. The isolates were tested for mecA gene, antibiotic resistance, and enterotoxin genes (sea, seb, sec, sed, see, seg, seh, and sei). Most isolates carried sea, seg, and sei genes, and seg-sei was the most frequent enterotoxin profile. About 88.5% of the S. aureus exhibited resistance to at least one antibiotic. High resistance to penicillin and ampicillin; low resistance to tetracycline, erythromycin, rifampin, and clindamycin; and very low resistance to cefotaxime, amoxicillin-clavulanic acid, gentamicin, and ciprofloxacin were exhibited by S. aureus from the three countries. In addition, some antibiotic resistance exhibited a strong correlation (P ≤ 0.01) with enterotoxigenicity in S. aureus. The study concluded that the large amount of globally traded fish increases the possibility of intercontinental transmission of enterotoxigenic and multidrug-resistant S. aureus through fish and highlights the potential influence of local fish handling and processing on consumer health worldwide. The introduction of periodic training in food safety and hygiene is essential to increase fish handlers' awareness of good hygienic practices in handling fish. These findings also enrich the ongoing debate about the risk of methicillin-and multidrug-resistant S. aureus as a foodborne pathogen compared with drug-susceptible S. aureus.