Identification of Livestock-Associated Methicillin-Resistant Staphylococcus aureus Isolates in Korea and Molecular Comparison Between Isolates from Animal Carcasses and Slaughterhouse Workers

Abstract This study was undertaken to screen methicillin-resistant Staphylococcus aureus (MRSA) in animal carcasses and slaughterhouse workers and characterize MRSA isolates identified during 2010–2012 in Korea. A total of 830 (16.4%) S. aureus and 65 (1.3%) MRSA were isolated from 9669 carcass samples. MRSA was more frequently detected in chicken carcasses (1.2%) than in cattle (0.3%) and pig carcasses (0.6%). The prevalence of MRSA in workers was 6.9% (4/58) in chicken slaughterhouse workers, but no MRSA was detected in pig and cattle slaughterhouse workers (0/41). Two different lineages of MRSA were identified (i.e., human-associated type [ST5, ST59, and ST72] and livestock-associated [LA] type [ST398, ST541, and ST692]); only LA MRSA was observed in chicken carcasses, whereas both types were found in cattle and pig carcasses and workers. All human-associated MRSA isolates carried enterotoxin and/or leukotoxin genes, whereas LA MRSA types did not carry these genes, except ST692 type. However, all LA MR...