Date Full Report Received


Date Abstract Report Received



Primary Investigator:
Co-Investigators: Wondwossen Gebreyes, Tara Smith
This report combines the results of collaborative projects between the University of Minnesota (Dr. Peter Davies), University of Iowa (Dr. Tara Smith) and the Ohio State University (Dr. Wondwossen Gebreyes) that have been reported individually (NPB 08-178, 08-179 and 08-180). Since 2004, reports of MRSA in animals worldwide and apparent animal-to-human transmission have raised concerns about the role of animal populations, and particularly pigs and cattle, as potential reservoirs of zoonotic MRSA infections. The aim of the study was to estimate the prevalence and molecular types of methicillin-resistant Staphylococcus aureus (MRSA) on swine farms in major swine producing states in the USA. We collected nasal swabs from pigs and farm workers at 45 swine herds (21 antibiotic-free herds; 24 conventional herds) in Illinois, Iowa, Minnesota, North Carolina and Ohio.  MRSA was isolated from 50 of 1085 pigs (4.6%) and 31 of 148 (20.9%) of farm workers. MRSA-positive pigs and people were clustered in four conventional swine farms in Iowa and Illinois. This confirms the presence of MRSA in pigs and swine farm workers in the USA, but the prevalence found is relatively low compared with European studies.  Although MRSA may present an occupational hazard to swine workers in confinement buildings on some farms, there is little evidence to date suggesting a significant human or animal health impact of MRSA associated with livestock.