A recent study conducted by the University of Iowa College of Public Health and the Institute for Agriculture and Trade Policy examined the presence of methicillin-resistant Staphylococcus aureus (MRSA) on pork samples selected from retail chain stores in Iowa, Minnesota, and New Jersey.

In the study, pork products, both pre-packaged and individually wrapped at the meat counter, were examined. The study tested a wide range of raw pork products, some of which could be found in all three states, but most of which were part of local or regional chains.

Of 395 pork samples collected from a total of 36 stores, 26 samples, or 6.6 percent, were found to carry MRSA, while 230 samples, 58.2 percent, were found to carry methicillin-sensitive S. aureus (MSSA)

The study also tested potential differences in the presence of S. aureus between conventional pork products and “alternative” pork products- those from animals raised without antibiotics. The study found no statistically significant differences for the prevalence of S. aureus in general, or MSSA or MRSA specifically, when comparing pork products from conventionally raised swine and swine raised without antibiotics.

“Although this study did detect MRSA in a percentage of meat products at a level comparable or less than that observed in other countries, it is important to note that MRSA is not considered a food safety issue,” according to Jennifer Koeman, DVM, director of producer and public health, National Pork Board. “International food safety authorities have stated that there is very little, if any, foodborne risk from MRSA in meat.”

The study was unable to determine the source of the contamination. “The MRSA found in pigs does not cause illness in the animals and does not require pork producers to use antibiotics to control it,” according to Koeman. As with all food, basic good handling and preparation procedures should be followed when consuming pork and pork products to ensure food safety, according to NPB.

The study represents the largest sampling of raw meat products for MRSA contamination to date in the United States. MRSA prevalence on pork products was higher than in previous U.S.-conducted studies, although similar to that in Canadian studies.

“This study confirms the presence of S. aureus on raw pork products in the United States, regardless of whether produced conventionally or from animals raised without antibiotics/antibiotic growth promotants,” according to a discussion on the study by researcher Ashley O'Brien, Department of Epidemiology, College of Public Health, University of Iowa. “No statistically significant differences were observed when comparing S. aureus (whether MSSA or MRSA) positivity on conventional and alternative pork products.”

Read the study summary.

Source: Plos One