Fox A, Pichon B, Wilkinson H, Doumith M, Hill R L R, McLauchlin J, Kearns A M
Public Health England, Food Water and Environmental Microbiology Services, Preston Laboratory, Preston, UK.
Antimicrobial Resistance and Healthcare Infections Reference Unit, National Infection Service, Public Health England, London, UK.
Lett Appl Microbiol. 2017 Mar;64(3):239-245. doi: 10.1111/lam.12709. Epub 2017 Jan 28.
Limited data are available on the prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in the UK. We tested 124 raw meat samples for MRSA including pork (n = 63), chicken (n = 50) and turkey (n = 11) collected from retail outlets in North West England between March and July 2015. MRSA was recovered from nine (7·3%) samples (four chicken, three pork and two turkey) from different butchers and supermarkets. Four were labelled of UK origin, three were from continental Europe; the origin was not specified for two samples. Whole-genome sequencing (WGS), spa typing and the presence of lineage-specific canonical single nucleotide polymorphisms confirmed that they belonged to the livestock-associated clade of clonal complex (CC) 398. Seven (77·8%) isolates were multi-drug resistant. Phylogenetic analyses showed the isolates were diverse, suggesting multiple silent introductions of LA-MRSA into the UK food chain. Two chicken meat isolates belonged to a sub-clade recently reported from human cases in Europe where poultry meat was the probable source. The low levels of MRSA identified (<20 CFU per g) and absence of enterotoxin genes suggest the risk of acquisition of, or food-poisoning due to, LA-MRSA is low. Nevertheless, the MRSA contamination rate is higher than previously estimated; further evaluation of the public health impacts of LA-MRSA is warranted.
Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is a public health concern worldwide, but has only been reported sporadically in the UK. In the largest UK study to date, samples of raw meat at retail sale were examined for both the presence and levels of MRSA. We report the first isolations of CC398 LA-MRSA from poultry meat in the UK including representatives of a particular sub-clade associated with cases of human infection/colonization in Europe. Although levels were low (<20 CFU per g), the contamination rate was higher than previous UK studies. Moreover, whole-genome sequencing revealed multiple independent introductions of LA-MRSA into the UK food chain.
关于英国与牲畜相关的耐甲氧西林金黄色葡萄球菌（LA-MRSA）的流行情况，可用数据有限。我们检测了124份生肉样本中的MRSA，这些样本包括2015年3月至7月间从英格兰西北部零售店采集的猪肉（n = 63）、鸡肉（n = 50）和火鸡肉（n = 11）。从不同肉店和超市采集的9份（7.3%）样本（4份鸡肉、3份猪肉和2份火鸡肉）中检出了MRSA。4份样本标记为原产于英国，3份来自欧洲大陆；2份样本未注明来源。全基因组测序（WGS）、spa分型以及谱系特异性标准单核苷酸多态性的存在证实，它们属于克隆复合体（CC）398的与牲畜相关的进化枝。7份（77.8%）分离株具有多重耐药性。系统发育分析表明，这些分离株具有多样性，提示LA-MRSA多次悄然传入英国食物链。2份鸡肉分离株属于欧洲近期在人类病例中报道的一个亚进化枝，其中禽肉可能是传染源。检出的MRSA水平较低（每克<20 CFU）且无肠毒素基因，这表明因LA-MRSA而感染或食物中毒的风险较低。然而，MRSA污染率高于先前估计；有必要进一步评估LA-MRSA对公共卫生的影响。
与牲畜相关的耐甲氧西林金黄色葡萄球菌（LA-MRSA）是全球公共卫生关注的问题，但在英国仅偶尔有报道。在英国迄今为止规模最大的一项研究中，对零售生肉样本进行了MRSA的存在情况和水平检测。我们报告了在英国首次从禽肉中分离出CC398 LA-MRSA，包括与欧洲人类感染/定植病例相关的一个特定亚进化枝的代表。尽管水平较低（每克<20 CFU），但污染率高于英国先前的研究。此外，全基因组测序揭示了LA-MRSA多次独立传入英国食物链。
