High clonal diversity in erythromycin-resistant Streptococcus pneumoniae invasive isolates in Madrid, Spain (2000-07)
High clonal diversity in erythromycin-resistant Streptococcus pneumoniae invasive isolates in Madrid, Spain (2000-07)
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DOI：
10.1093/jac/dkp364
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发表时间：
2009-12-01
影响因子：
5.2
通讯作者：
Canton, Rafael
中科院分区：
文献类型：
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作者：
de la Pedrosa, Elia Gomez G.;Baquero, Fernando;Canton, Rafael
肺炎链球菌对红霉素的耐药性在世界范围内仍在增加。所有78株红霉素耐药的S.对我院2000 ~ 2007年血培养分离的肺炎克雷伯菌进行了研究，用不同的数学多样性指数分析了其种群结构，用PCR方法筛选了红霉素耐药决定簇。利用克隆多样性指数（多样性比、Simpson指数、Selander-Levin指数和Shannon指数）分析了该菌的群体结构（包括多位点序列分型），结果表明，主要抗性基因为β（B）（占74.3%），其次为β（B）+mef（A）组合（占17.9%）和mef（A）单独（占7.7%）。最常见的血清型为14型（18%）、19 A型（15.4%）和6 B型（11.5%）。在抗性菌株中检测到多克隆结构，包括西班牙（9V）-3、西班牙（6 B）-2和丹麦（14）-32国际克隆。结果表明，该品系具有较高的遗传多样性和遗传分布，尤其是在含有抗性决定子的无性系中，多个抗性决定子中存在抗性决定子和抗性决定子的组合。肺炎菌血症克隆。多克隆结构的保存可能为抗生素耐药性的进一步进化提供合适的背景。
Erythromycin resistance in Streptococcus pneumoniae is still increasing worldwide. All 78 erythromycin-resistant S. pneumoniae isolates collected from blood cultures in our hospital (2000-07) were studied and the population structure was analysed by using different mathematical diversity indexes.Erythromycin resistance determinants were screened by PCR. The population structure, including multilocus sequence typing, was analysed by using quantitative clonal diversity (diversity ratio, Simpson, Selander-Levin and Shannon mathematical indexes).The leading resistance gene was erm(B) (74.3% of the isolates), followed by the erm(B) plus mef(A) combination (17.9%) and mef(A) alone (7.7%). The most frequent serotypes were 14 (18%), 19A (15.4%) and 6B (11.5%). A polyclonal structure was detected in resistant strains, including the Spain(9V)-3, Spain(6B)-2 and Denmark(14)-32 international clones. Both genetic diversity and genetic distribution were high, particularly among clones containing erm(B) and erm(B) plus mef(A) determinants.The resistance determinants erm(B) and the combination of erm(B) plus mef(A) were observed within multiple S. pneumoniae bacteraemic clones. The preservation of a polyclonal structure might provide a suitable background for further evolution of antibiotic resistance.