Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.
Lett Appl Microbiol. 2010 Sep;51(3):338-42. doi: 10.1111/j.1472-765X.2010.02901.x. Epub 2010 Jul 14.
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.
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.
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.
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.
本研究旨在确定零售肉中耐甲氧西林金黄色葡萄球菌（MRSA）污染的流行率，并确定污染水平。
在加拿大四个省的零售点购买猪肉（猪排和绞肉）、牛肉和鸡肉（鸡腿、鸡翅和大腿），并使用定性和定量方法检测耐甲氧西林金黄色葡萄球菌的存在。从 9.6%的猪肉、5.6%的牛肉和 1.2%的鸡肉样本中分离出 MRSA（P = 0.0002）。MRSA 的含量通常较低，37%低于定量检测的下限，大多数可定量样本中存在 <100 CFU/g。所有分离株均通过脉冲场凝胶电泳（PFGE）分类为加拿大流行型 MRSA-2（CMRSA-2），具有两种不同的 PFGE 亚型，spa 型为 24/t242。
零售肉中 MRSA 污染并不罕见。虽然在加拿大的猪中发现了人类流行克隆 CMRSA-2，但未分离出与牲畜相关的 ST398 令人惊讶。
MRSA 污染肉类的相关性尚不清楚，但需要进行调查，因为这可能会导致食品处理过程中的暴露。需要调查污染来源，因为这些结果表明可能涉及人类或动物来源。
