Prevalence and characterization of methicillin-resistant Staphylococcus aureus isolates in food industry workers

BACKGROUND. Methicillin-resistant S. aureus (MRSA) is a pathogen spread not only in the hospital environment but also in the community and amongst livestock (LA-MRSA). LA-MRSA can be transmitted to humans that live in close contact with MRSA-colonized animals, and human colonization and/or infection has been reported worldwide, particularly among those involved with livestock farming. In this study the authors evaluated the prevalence of S. aureus and MRSA among healthy carriers who worked in the food industry in Apulia, Southern Italy. METHODS:Nasal swabs were taken from pasta and pork industry workers. All swab samples were subjected to tests for the isolation, identification and typing of S. aureus and MRSA strains. The identification of the strains was confirmed by molecular assessment using multiplex-PCR for the amplification of the nuc and mecA genes. The strains identified as MRSA were then subjected to a PCR protocol for the characterization of sequence type ST398. RESULTS: In total 26.3% of examined nasal swabs were positive for S. aureus, 8.2% of them were methicillin resistant strains and 28.5% of MRSA isolates were characterized as ST398. The MRSA prevalence among pork factory workers was 3% , whereas among the pasta operators the prevalence was 11.5. CONCLUSION: The presence of S. aureus and MRSA among food workers represents a public health risk. Further, considering the dissemination of S. aureus and MRSA among non-nosocomial environments, including communities and livestock, careful surveillance and continuous monitoring of the emergence of MRSA is fundamental for safeguarding public health.