Department of Microbiology, Faculty of Medicine, Health Sciences Centre, Kuwait University, Jabriya, Kuwait.
Med Princ Pract. 2011;20(3):213-9. doi: 10.1159/000321242. Epub 2011 Mar 29.
To investigate the extent, distribution and sequence analysis of bla(CTX-M) genes carried by Escherichia coli isolated from patients admitted to all government hospitals in Kuwait.
Extended-spectrum β-lactamase (ESBL)-producing E. coli isolates were collected from the 8 major hospitals in Kuwait. CTX-M ESBLs were analyzed by PCR and sequenced. Clonality of the positive isolates was determined for genetic relatedness using pulsed-field gel electrophoresis (PFGE) with XbaI digestion of the genomic DNA.
Of the 136 ESBL-positive isolates, 106 (77.9%) harbored bla(CTX-M) genes. Among these, bla(CTX-M-15) was the most frequent with a prevalence rate of 84.1%, followed by bla(CTX-M-14) (6.8%), bla(CTX-M-14b) (5.7%) and bla(TOHO-1) (3.4%). Ninety-three (87.7%) were isolated from Kuwaiti (35.9%), Egyptian (31.1%) and Indian (20.8%) nationals; the majority of isolates positive for bla(CTX-M-15) were mainly from these 3 nationalities. PFGE analysis did not demonstrate any clustering of positive isolates in any particular hospital.
This study confirms an explosive emergence of CTX-M-15 β-lactamase among E. coli isolates in Kuwait and shows that the strains were clonally heterogeneous with no evidence of inter- or intra-hospital spread. Thus Kuwait may represent an important source of CTX-M-15-positive E. coli.
调查科威特所有政府医院住院患者分离的大肠埃希菌中携带 bla(CTX-M)基因的程度、分布和序列分析。
从科威特 8 家主要医院收集产超广谱β-内酰胺酶（ESBL）的大肠埃希菌分离株。通过 PCR 分析 CTX-M ESBL 并测序。对阳性分离株进行克隆性分析，用 XbaI 消化基因组 DNA 进行脉冲场凝胶电泳（PFGE），以确定遗传相关性。
在 136 株 ESBL 阳性分离株中，106 株（77.9%）携带 bla(CTX-M)基因。其中 bla(CTX-M-15)最为常见，检出率为 84.1%，其次是 bla(CTX-M-14)（6.8%）、bla(CTX-M-14b)（5.7%）和 bla(TOHO-1)（3.4%）。93 株（87.7%）分离自科威特（35.9%）、埃及（31.1%）和印度（20.8%）国民；bla(CTX-M-15)阳性分离株主要来自这 3 个国家。PFGE 分析未显示任何特定医院的阳性分离株聚类。
本研究证实了 CTX-M-15 型β-内酰胺酶在科威特大肠埃希菌分离株中的爆发性出现，并表明这些菌株具有克隆异质性，没有证据表明医院内或医院间的传播。因此，科威特可能是 CTX-M-15 阳性大肠埃希菌的一个重要来源。
