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Updated: Jun 10, 2026
Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
Detection and quantification of methicillin-resistant Staphylococcus aureus (MRSA) clones in retail meat products
J S Weese1, B P Avery, R J Reid-Smith
1Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada. jsweese@uoguelph.ca
Aims:
The objective of the study was to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) contamination of retail meat and to determine the level of contamination.
Methods And Results:
Pork (pork chops and ground pork), ground beef and chicken (legs, wings and thighs) were purchased at retail outlets in four Canadian provinces and tested for the presence of methicillin-resistant Staph. aureus using qualitative and quantitative methods. MRSA was isolated from 9.6% of pork, 5.6% of beef and 1.2% of chicken samples (P = 0.0002). Low levels of MRSA were typically present, with 37% below the detection threshold for quantification and <100 CFU g(-1) present in most quantifiable samples. All isolates were classified as Canadian epidemic MRSA-2 (CMRSA-2) by pulsed field gel electrophoresis (PFGE), with two different PFGE subtypes, and were spa type 24/t242.
Conclusions:
MRSA contamination of retail meat is not uncommon. While CMRSA-2, a human epidemic clone, has been found in pigs in Canada, the lack of isolation of livestock-associated ST398 was surprising.
Significance And Impact Of The Study:
The relevance of MRSA contamination of meat is unclear but investigation is required because of the potential for exposure from food handling. Sources of contamination require investigation because these results suggest that human or animal sources could be involved.
Insights
Methicillin-resistant Staphylococcus aureus (MRSA) was found in retail meat across Canada. This common contamination, particularly in pork, highlights potential food handling risks and requires further investigation into its sources.
Area of Science:
- Food safety and microbiology
- Antimicrobial resistance
- Public health
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) is a significant public health concern.
- Understanding MRSA prevalence in the food chain is crucial for risk assessment.
- Previous studies have indicated MRSA presence in livestock, but retail meat data is less common.
Purpose of the Study:
- To determine the prevalence and levels of MRSA contamination in retail meat products sold in Canada.
- To identify the specific MRSA strains present in retail meat.
- To explore potential sources and implications of MRSA in the food supply.
Main Methods:
- Retail meat samples (pork, beef, chicken) were collected from four Canadian provinces.
- Qualitative and quantitative methods were employed to detect and quantify MRSA.
- Pulsed field gel electrophoresis (PFGE) and spa typing were used for isolate characterization.
Main Results:
- MRSA was detected in 9.6% of pork, 5.6% of beef, and 1.2% of chicken samples.
- Contamination levels were generally low, with many samples below detection limits.
- All isolates were identified as Canadian epidemic MRSA-2 (CMRSA-2), a human epidemic clone, with two PFGE subtypes and spa type 24/t242.
Conclusions:
- MRSA contamination of retail meat is relatively common in Canada.
- The presence of CMRSA-2 in meat, a strain typically associated with humans, is notable.
- The absence of livestock-associated MRSA ST398 was unexpected, suggesting complex transmission dynamics.
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