Prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) among farm and slaughterhouse workers in Italy

Objective: We measured the prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in swine livestock workers, examined LA-MRSA resistance profile, and associated carriage with the working activities. Methods: Information was collected on demographics and occupational history. Swabs were collected and tested for the isolation of S. aureus, examined for antimicrobial susceptibility, and all MRSA underwent ST398qPCR assay. Results: LA-MRSA was isolated in 7.3% of the 396 enrolled workers. LA-MRSA colonization was more likely in farmers than in slaughterhouse workers (Fisher exact P ¼ 0.001). Carriage was associated with herd size, being less frequent in small/medium farms (odds ratio ¼ 0.20; 95% confidence interval ¼ 0.07 to 0.53), and with the number of working days per week (OR ¼ 2.11; 95% confidence interval ¼ 1.07 to 4.19). Conclusions: LA-MRSA carriage is strongly animal-exposure related, and educational intervention informing about the risks related to the activity with livestock is needed.