Wednesday, July 25, 2012
Exhibit Hall (Rhode Island Convention Center)
Introduction: Methicillin-resistant Staphylococcus aureus is of increasing concern due to its resistance to multiple antibiotics and its recent detection in retail meat products. Current scientific literature suggests that the amount of MRSA in pork products is low. However, the possible impact on food safety at the consumer level due to retail pork products contaminated with MRSA still needs to be elucidated.
Purpose: The aim of this study was to evaluate the potential risk of consumer exposure to MRSA from contaminated food contact surfaces and contaminated retail pork products.
Methods: Pork loins, bacon and pork sausage were inoculated with a four strain MRSA cocktail, swabbed for initial bacterial populations, vacuum packaged and stored for two weeks at 4 °C to simulate normal packaging and distribution. Polyethylene cutting boards, knives and pork skin were contaminated with the inoculated product lying on the surface for 5 minutes. Polyethylene cutting boards and knives were also contaminated by placing a 500 g lead donut on the product while it is dragged across the transfer surface. 5 cm x 5 cm areas were swabbed and bacterial populations of the inoculated pork products and contact surfaces were enumerated on Baird-Parker Agar and reported as log cfu/cm².
Results: All 6 pork loins inoculated with 10 CFU/ml MRSA cocktail and swabbed before storage yielded an average of 4.8 log CFU/cm². Post-storage swabs of transfer surfaces in contact with the contaminated loin were 3.9 log CFU/cm², 2.7 log CFU/cm² and 4.1 log CFU/cm² for the cutting board, knife and pork skin, respectively. Post-storage swabs of the pork skin after weighted exposure to the contaminated transfer surfaces yielded 3.3 log CFU/cm² and 3.2 log CFU/cm² for the cutting board and knife, respectively. Similar log CFU/cm² values were observed for the bacon and pork sausage samples.
Significance: These results suggest that there is a potential risk for consumer exposure to low cell concentrations (10 CFU/cm²) of MRSA on pork products.
Significance: These results suggest that there is a potential risk for consumer exposure to low cell concentrations (10 CFU/cm²) of MRSA on pork products.