<em>Staph aureus</em> Found Along Pork Production Chain

Methicillin-resistant Staphylococcus aureus was identified at all stages of the production chain, according to recently published research from Germany, with contamination rates highest in nasal swabs and lower on carcasses, meat at processing and in final products.

11 January 2011

3 minute read

Birgit Beneke from the Institute of Chemical and Veterinary Analysis Ostwestfalen-Lippe in Detmold and co-authors there and at the Federal Institute for Risk Assessment in Berlin have published their investigations into the prevalence of of methicillin-resistant Staphylococcus aureus (MRSA) in a fresh meat pork production chain in the latest issue of Journal of Food Protection.

The objective of their study, they explain, was to investigate the prevalence of methicillin-resistant Staphylococcus aureus at different stages of a fresh pork production chain to reveal potential carry-over from live animals to meat.

Samples were collected at different stages of the production process in a large German abattoir with an integrated processing unit for fresh pork. Samples included nasal swabs from pigs at stunning, environmental samples from the slaughter line, surface samples from carcasses, environmental and meat samples from the processing unit, and samples from final products.

Samples were analysed with an established two-step selective enrichment method, and isolates were characterised with respect to their S. aureus protein A gene (spa) and staphylococcal cassette chromosome mec (SCCmec; which harbours the mecA gene) types.

Contamination rate was highest (64.7 per cent) in nasal swabs and lower (6.0 per cent) on carcasses, meat at processing (4.2 per cent), and final products (2.8 per cent). Environmental samples were positive along the slaughter line (12 per cent) but not in the processing unit. spa types t011 and t034 and SCCmec type V predominated the isolates. Heterogeneity of spa types was highest in nasal swabs.

Results show that methicillin-resistant S. aureus can be identified at all stages of the production chain, conclude Beneke and co-authors.

The researchers added that further studies are needed to identify potential control points to reduce the carry-over from farm animals to the final products.

Reference

Beneke, B., S. Klees, B. Stührenberg, A. Fetsch, B. Kraushaar and B-A. Tenhagen. 2011. Prevalence of methicillin-resistant Staphylococcus aureus in a fresh meat pork production chain. Journal of Food Protection, 74 (1):126-129.