Meticillin-resistant Staphylococcus aureus with a novel mecA homologue in human and bovine populations in the UK and Denmark: a descriptive study.
Meticillin-resistant Staphylococcus aureus with a novel mecA homologue in human and bovine populations in the UK and Denmark: a descriptive study.
复制标题
DOI：
10.1016/s1473-3099(11)70126-8
复制
发表时间：
2011-08
影响因子：
56.3
通讯作者：
Holmes, Mark A.
中科院分区：
文献类型：
--
作者：
Garcia-Alvarez, Laura;Holden, Matthew T. G.;Lindsay, Heather;Webb, Cerian R.;Brown, Derek F. J.;Curran, Martin D.;Walpole, Enid;Brooks, Karen;Pickard, Derek J.;Teale, Christopher;Parkhill, Julian;Bentley, Stephen D.;Edwards, Giles F.;Girvan, E. Kirsty;Kearns, Angela M.;Pichon, Bruno;Hill, Robert L. R.;Larsen, Anders Rhod;Skov, Robert L.;Peacock, Sharon J.;Maskell, Duncan J.;Holmes, Mark A.
动物可以作为一个水库和来源出现新的耐甲氧西林金黄色葡萄球菌（MRSA）克隆在人类。在这里，我们报告的发现，从散装牛奶中分离的金黄色葡萄球菌（LGA 251），是表型耐甲氧西林，但测试阴性的mecA基因和初步调查的程度，这种菌株存在于牛和人类的人口。牛MRSA分离株获自英国兽医实验室机构，人MRSA分离株获自诊断或参考实验室（两个在英国，一个在丹麦）。从这些集合中，我们搜索了显示表型甲氧西林耐药的mecA PCR阴性牛和人金黄色葡萄球菌分离株。我们使用全基因组测序来建立观察到的抗生素耐药性的遗传基础。在位于新型葡萄球菌盒式染色体mec元件的LGA 251基因组中发现了一个趋异mecA同源物（mecALGA 251），命名为XI型SCCmec。mecALGA 251与金黄色葡萄球菌mecA同源物具有70%的相同性，最初在英格兰奶牛的15株金黄色葡萄球菌分离株中检测到。这些分离株来自三个不同的多位点序列类型谱系（CC 130、CC 705和ST 425）;在60%的牛分离株中鉴定出spa型t843（与CC 130相关）。当测试人类mecA阴性MRSA分离株时，在来自苏格兰的16株分离株中的12株、来自英格兰的26株分离株中的15株和来自丹麦的32株分离株中的24株中鉴定出mecALGA 251同源物。与奶牛一样，t843是人类中检测到的最常见的spa类型。尽管常规培养和抗菌药物敏感性试验将鉴定具有这种新型mecA同源物的金黄色葡萄球菌分离株为甲氧西林耐药，但目前的确证性方法不能鉴定它们为MRSA。MRSA检测的新诊断指南应考虑纳入mecALGA 251检测。环境、食品和农村事务部、英格兰高等教育资助理事会、艾萨克·牛顿信托基金（剑桥大学）和惠康信托基金。
Animals can act as a reservoir and source for the emergence of novel meticillin-resistant Staphylococcus aureus (MRSA) clones in human beings. Here, we report the discovery of a strain of S aureus (LGA251) isolated from bulk milk that was phenotypically resistant to meticillin but tested negative for the mecA gene and a preliminary investigation of the extent to which such strains are present in bovine and human populations. Isolates of bovine MRSA were obtained from the Veterinary Laboratories Agency in the UK, and isolates of human MRSA were obtained from diagnostic or reference laboratories (two in the UK and one in Denmark). From these collections, we searched for mecA PCR-negative bovine and human S aureus isolates showing phenotypic meticillin resistance. We used whole-genome sequencing to establish the genetic basis for the observed antibiotic resistance. A divergent mecA homologue (mecALGA251) was discovered in the LGA251 genome located in a novel staphylococcal cassette chromosome mec element, designated type-XI SCCmec. The mecALGA251 was 70% identical to S aureus mecA homologues and was initially detected in 15 S aureus isolates from dairy cattle in England. These isolates were from three different multilocus sequence type lineages (CC130, CC705, and ST425); spa type t843 (associated with CC130) was identified in 60% of bovine isolates. When human mecA-negative MRSA isolates were tested, the mecALGA251 homologue was identified in 12 of 16 isolates from Scotland, 15 of 26 from England, and 24 of 32 from Denmark. As in cows, t843 was the most common spa type detected in human beings. Although routine culture and antimicrobial susceptibility testing will identify S aureus isolates with this novel mecA homologue as meticillin resistant, present confirmatory methods will not identify them as MRSA. New diagnostic guidelines for the detection of MRSA should consider the inclusion of tests for mecALGA251. Department for Environment, Food and Rural Affairs, Higher Education Funding Council for England, Isaac Newton Trust (University of Cambridge), and the Wellcome Trust.