School of Life Sciences, University of Hull, Hull, HU6 7RX, UK.
Easter Bush Pathology, Royal (Dick) School of Veterinary Studies, UK; The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK.
J Glob Antimicrob Resist. 2020 Sep;22:139-144. doi: 10.1016/j.jgar.2020.01.013. Epub 2020 Jan 30.
To investigate the prevalence and characteristics of methicillin-resistant staphylococci on dairy farms in England and Wales including zoonotic MRSA.
Bulk tank milk was sampled from 363 dairy farms in 2015-2016 and methicillin-resistant staphylococci were isolated by salt broth enrichment and plating on MRSA Brilliance selective agar. Isolates were characterised through antimicrobial susceptibility testing and whole-genome sequencing.
Methicillin-resistant staphylococci were isolated from ∼5% of dairy farms and belonged to six different species, Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus lentus, Staphylococcus saprophyticus, Staphylococcus fleurettii and Staphylococcus sciuri. Whole-genome sequencing revealed a large variety of antimicrobial resistance genes and SCCmec elements were present, including mecA and mecC alleles. Potentially zoonotic methicillin-resistance S. aureus were found at a low prevalence (0.83% of sampled dairy farms). Whole-genome sequencing also provided evidence for the mobility of a primordial mec gene complex, independently of a SCCmec element, which appears to have been acquired by S. saprophyticus from S. fleurettii.
These data give new insight into the epidemiology of veterinary methicillin-resistant staphylococci to inform future surveillance and zoonotic risk evaluation. Our data indicate that MRSA has likely decreased in prevalence since earlier survey work in England and Wales during 2011-12 and highlights the diversity of methicillin resistance and other resistance determinants among bovine-associated staphylococci with implications for veterinary and human medicine.
调查英格兰和威尔士奶牛场耐甲氧西林葡萄球菌（包括人畜共患病耐甲氧西林金黄色葡萄球菌）的流行情况和特征。
2015-2016 年，从 363 个奶牛场采集了牛奶样品，通过盐肉汤富集和 MRSA 光辉选择性琼脂平板培养分离耐甲氧西林葡萄球菌。通过药敏试验和全基因组测序对分离株进行特征分析。
从约 5%的奶牛场分离出耐甲氧西林葡萄球菌，属于六个不同的种，金黄色葡萄球菌、表皮葡萄球菌、缓症葡萄球菌、腐生葡萄球菌、弗氏葡萄球菌和松鼠葡萄球菌。全基因组测序揭示了大量不同的抗菌药物耐药基因和 SCCmec 元件，包括 mecA 和 mecC 等位基因。低流行率（抽样奶牛场的 0.83%）发现了潜在的人畜共患耐甲氧西林金黄色葡萄球菌。全基因组测序还提供了证据表明，一个原始 mec 基因复合物在没有 SCCmec 元件的情况下独立移动，这似乎是由 S. saprophyticus 从 S. fleurettii 中获得的。
这些数据为兽医耐甲氧西林葡萄球菌的流行病学提供了新的见解，以指导未来的监测和人畜共患病风险评估。我们的数据表明，自 2011-12 年在英格兰和威尔士进行的早期调查工作以来，MRSA 的流行率可能有所下降，并强调了牛相关葡萄球菌中耐甲氧西林和其他耐药决定因素的多样性，这对兽医和人类医学都有影响。
