西班牙卢戈地区产超广谱β-内酰胺酶大肠杆菌的分子流行病学：产CTX-M-15的O25b:H4-ST131克隆的传播
Molecular epidemiology of Escherichia coli producing extended-spectrum {beta}-lactamases in Lugo (Spain): dissemination of clone O25b:H4-ST131 producing CTX-M-15.
作者信息
Blanco Miguel, Alonso Maria Pilar, Nicolas-Chanoine Marie-Hélène, Dahbi Ghizlane, Mora Azucena, Blanco Jesús E, López Cecilia, Cortés Pilar, Llagostera Montserrat, Leflon-Guibout Véronique, Puentes Beatriz, Mamani Rosalía, Herrera Alexandra, Coira María Amparo, García-Garrote Fernando, Pita Julia María, Blanco Jorge
机构信息
Departamento de Microbioloxía e Parasitolxía, Universidade de Santiago de Compostela, Lugo, Spain.
出版信息
J Antimicrob Chemother. 2009 Jun;63(6):1135-41. doi: 10.1093/jac/dkp122. Epub 2009 Apr 7.
OBJECTIVES
Having shown that the Xeral-Calde Hospital in Lugo (Spain) has been concerned by Escherichia coli clone O25:H4-ST131 producing CTX-M-15 (Nicolas-Chanoine et al. J Antimicrob Chemother 2008; 61: 273-81), the present study was carried out to evaluate the prevalence of this clone among the extended-spectrum beta-lactamase (ESBL)-producing E. coli isolates and also to molecularly characterize the E. coli isolates producing ESBL other than CTX-M-15.
METHODS
In the first part of this study, 105 ESBL-producing E. coli isolates (February 2006 to March 2007) were characterized with regard to ESBL enzymes, serotypes, virulence genes, phylogenetic groups, multilocus sequence typing (MLST) and PFGE. In the second part of this study, 249 ESBL-producing E. coli isolates (April 2007 to May 2008) were investigated only for the detection of clone O25b:H4-ST131 producing CTX-M-15 using a triplex PCR developed in this study and based on the detection of the new operon afa FM955459 and the targets rfbO25b and 3' end of the bla(CTX-M-15) gene.
RESULTS
Of the 105 ESBL-producing E. coli isolates, 60 (57.1%) were positive for CTX-M-14, 23 (21.9%) for CTX-M-15, 10 (9.5%) for SHV-12 and 7 (6.7%) for CTX-M-32. Serotypes, virulence genes, phylogenetic groups and molecular typing by PFGE demonstrated high homogeneity within those producing CTX-M-15 and high diversity within E. coli producing CTX-M-14 and other ESBLs. By PFGE, CTX-M-15-producing E. coli isolates O25b:H4 belonging to the phylogenetic group B2 and MLST profile ST131 were grouped in the same cluster. The epidemic strain of clone O25b:H4-ST131 represented 23.1%, 22.5% and 20.0% of all ESBL-producing E. coli isolated in 2006, 2007 and 2008, respectively.
CONCLUSIONS
CTX-M-type ESBLs, primarily CTX-M-14 and CTX-M-15, have emerged as the predominant types of ESBL produced by E. coli isolates in Lugo. In view of the reported findings, long-term care facilities for elderly people may represent a significant reservoir for E. coli clone O25b:H4-ST131 producing CTX-M-15. The triplex PCR developed in this work will be useful for rapid and simple detection of this clone.
目的
鉴于西班牙卢戈市的塞拉尔 - 卡尔德医院受到产CTX - M - 15的大肠杆菌克隆O25:H4 - ST131的影响（尼古拉斯 - 沙诺瓦等人，《抗菌化疗杂志》2008年；61: 273 - 81），本研究旨在评估该克隆在产超广谱β - 内酰胺酶（ESBL）的大肠杆菌分离株中的流行情况，并对产除CTX - M - 15之外的ESBL的大肠杆菌分离株进行分子特征分析。
方法
在本研究的第一部分，对105株产ESBL的大肠杆菌分离株（2006年2月至2007年3月）进行了ESBL酶、血清型、毒力基因、系统发育群、多位点序列分型（MLST）和脉冲场凝胶电泳（PFGE）分析。在本研究的第二部分，对249株产ESBL的大肠杆菌分离株（2007年4月至2008年5月）仅使用本研究开发的基于新操纵子afa FM955459以及rfbO25b和bla(CTX - M - 15)基因3'端检测的三重PCR来检测产CTX - M - 15的O25b:H4 - ST131克隆。
结果
在105株产ESBL的大肠杆菌分离株中，60株（57.1%）CTX - M - 14阳性，23株（21.9%）CTX - M - 15阳性，10株（9.5%）SHV - 12阳性，7株（6.7%）CTX - M - 32阳性。血清型、毒力基因以及PFGE分子分型显示，产CTX - M - 15的菌株具有高度同质性，而产CTX - M - 14和其他ESBL的大肠杆菌具有高度多样性。通过PFGE分析，属于系统发育群B2且MLST型别为ST131的产CTX - M - 15的大肠杆菌分离株O25b:H4被归为同一簇。克隆O25b:H4 - ST131的流行菌株分别占2006年、2007年和2008年分离的所有产ESBL大肠杆菌的23.1%、22.5%和20.0%。
结论
CTX - M型ESBL，主要是CTX - M - 14和CTX - M - 15，已成为卢戈市大肠杆菌分离株产生的主要ESBL类型。鉴于所报道的结果，老年人长期护理机构可能是产CTX - M - 15的大肠杆菌克隆O25b:H4 - ST131的重要储存库。本研究开发的三重PCR将有助于快速、简便地检测该克隆。
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