The arginine catabolic mobile element and staphylococcal chromosomal cassette mec linkage:: Convergence of virulence and resistance in the USA300 clone of methicillin-resistant Staphylococcus aureus
The arginine catabolic mobile element and staphylococcal chromosomal cassette mec linkage:: Convergence of virulence and resistance in the USA300 clone of methicillin-resistant Staphylococcus aureus
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DOI：
10.1086/587907
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发表时间：
2008-06-01
影响因子：
6.4
通讯作者：
Chambers, Henry F.
中科院分区：
文献类型：
--
作者：
Diep, Binh An;Stone, Gregory G.;Chambers, Henry F.
社区相关耐甲氧西林金黄色葡萄球菌的流行特征，特别是地理上广泛分布的克隆USA 300，知之甚少。USA 300分离株携带一个IV型葡萄球菌染色体盒mec（SCCmec）元件，赋予β-内酰胺类抗生素耐药性和一个推定的致病岛，精氨酸分解代谢移动的元件（ACME）。SCCmec和ACME之间的物理联系表明，抗生素抗性和致病性的选择可能是相互关联的。我们在USA 300临床分离株中构建了含有SCCmec和ACME缺失的同基因突变体，以确定这些元件在兔菌血症模型中所起的作用。我们发现，删除IV型SCCmec不影响竞争健身，而删除ACME显着衰减的致病性或健身的USA 300。这些数据与ACME增强USA 300的生长和存活的模型一致，允许SCCmec的遗传“搭便车”。SCCmec反过来保护免受β-内酰胺的暴露。
The epidemic character of community-associated methicillin-resistant Staphylococcus aureus, especially the geographically widespread clone USA300, is poorly understood. USA300 isolates carry a type IV staphylococcal chromosomal cassette mec (SCCmec) element conferring beta-lactam antibiotic class resistance and a putative pathogenicity island, arginine catabolic mobile element (ACME). Physical linkage between SCCmec and ACME suggests that selection for antibiotic resistance and for pathogenicity may be interconnected. We constructed isogenic mutants containing deletions of SCCmec and ACME in a USA300 clinical isolate to determine the role played by these elements in a rabbit model of bacteremia. We found that deletion of type IV SCCmec did not affect competitive fitness, whereas deletion of ACME significantly attenuated the pathogenicity or fitness of USA300. These data are consistent with a model in which ACME enhances growth and survival of USA300, allowing for genetic "hitch-hiking" of SCCmec. SCCmec in turn protects against exposure to beta-lactams.