Methicillin resistant S. aureus (MRSA) has been identified as a contaminant of swine and meat associated with swine. This study set out to examine the prevalence of novel methicillin resistant associated traits in a collection of MRSA recovered from swine, and compared with non-S. aureus strains as well as isolates recovered from other production animals and humans. This study also focused on determining if methicillin resistance associated with the novel and emerging recently identified mecC resistance gene was occurring in pork production. Isolates identified as methicillin resistant were also assessed for the type of resistance identified in mecA positive strains. A total of 1130 isolates were assessed including 659 from production pigs at lairage and slaughter, human isolates (n=150), other production animals (n = 58), S. aureus from meat and deli meat samples (n = 75) and non-S. aureus isolates recovered from production animals and humans (n = 188) were also included in the analysis. The novel mecC gene was not detected in swine production, however variant types of mecA resistance were detected suggesting that methicillin resistance in swine may be evolving and changing. This data suggests that continuous monitoring for emerging methicillin resistance is important in assessing new resistances as they emerge as well as understanding the potential sources of these resistance and designing interventions to reduce the risk of resistance entering the food chain. The data also highlights that other species of Staphylococcus can be potential sources of methicillin resistance. 
Contact Information: Dr. Catherine M. Logue, 1802 University Blvd, VMRI #2&5, Iowa State University, Ames, IA 50011, USA. Ph 515 294 3785; e mail [email protected]