Characterization and prevalence of MefA, MefE, and the associated msr(D) gene in Streptococcus pneumoniae clinical isolates
Characterization and prevalence of MefA, MefE, and the associated msr(D) gene in Streptococcus pneumoniae clinical isolates
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DOI：
10.1128/jcm.42.8.3570-3574.2004
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发表时间：
2004-08-01
影响因子：
9.4
通讯作者：
Shortridge, D
中科院分区：
文献类型：
--
作者：
Daly, MM;Doktor, S;Shortridge, D
最近的研究表明，肺炎链球菌中导致获得性大环内酯类耐药的外排基因可以分为 mef(E) 或 mef(A)。发现 mef(A) 和 mef(E) 的遗传元件还携带与葡萄球菌中的 msr(A) 56% 同源的开放阅读框 (ORF)。对 1997 年至 2002 年在北美、欧洲、非洲和亚洲收集的 153 个 mef(+) 肺炎链球菌临床分离株中的 mef(A/E) 和 msr 样 ORF [msr(D)] 的流行率进行了评估。使用对 mef(A) 或 mef(E) 和 msr(D) 具有特异性的 PCR 引物筛选临床分离株。 mef(A)、mef(E) 和 msr(D) 是从 mef(+) 菌株中克隆出来的，并转化为肺炎链球菌的敏感感受态菌株。测试转化体的抗菌敏感性和外排泵诱导。这项工作的结果表明，mef(A) 在欧洲部分地区更常见，在加拿大也有一些发病率，并且 msr 样基因单独可以赋予外排表型。
Recent work has shown that the efflux genes in Streptococcus pneumoniae that are responsible for acquired macrolide resistance can be distinguished as either mef(E) or mef(A). The genetic elements on which mef(A) and mef(E) are found also carry an open reading frame (ORF) that is 56% homologous to msr(A) in Staphylococcus. The prevalence of mef(A/E) and of the msr-like ORF [msr(D)] was evaluated in 153 mef(+) S. pneumoniae clinical isolates collected in North America, Europe, Africa, and Asia from 1997 to 2002. Clinical isolates were screened with PCR primers specific for either mef(A) or mef(E) and for msr(D). mef(A), mef(E), and msr(D) were cloned from mef(+) strains and transformed into a susceptible, competent strain of S. pneumoniae. The transformants were tested for antimicrobial susceptibilities and efflux pump induction. The results of this work demonstrated that mef(A) is more often isolated in parts of Europe, with some incidence in Canada, and that the msr-like gene alone can confer the efflux phenotype.