Novel CTX-M β-lactamase genotype distribution and spread into multiple species of Enterobacteriaceae in Changsha, Southern China
Novel CTX-M β-lactamase genotype distribution and spread into multiple species of Enterobacteriaceae in Changsha, Southern China
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DOI：
10.1093/jac/dkp068
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发表时间：
2009-05-01
影响因子：
5.2
通讯作者：
Hawkey, Peter M.
中科院分区：
文献类型：
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作者：
Liu, Wen'en;Chen, Lamei;Hawkey, Peter M.
为了解湖南省肠杆菌科细菌中CTX-M和SHV超广谱β-内酰胺酶(ESBL)基因的分布情况，收集2004年10月至2005年7月从湖南长沙三家主要医院分离的425株肠杆菌科细菌，测定其对blA(CTX-M)和blA(SHV)基因的药敏结果。用随机扩增多态性DNA分析所有菌株的克隆性，ESBL阳性菌株的总阳性率为33.4%(142/425)。产超广谱β-内酰胺酶以CTX-M型为主，共检出大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌、产气肠杆菌、弗氏柠檬酸杆菌、普通变形杆菌和普鲁登西亚7个属/种，占76.8%。最常见的bla(CTX-M-14)、bla(CTX-M-3)和bla(CTX-M-15)基因型分别为47.7%、29.4%和17.4%。从湖南省产超广谱β-内酰胺酶(ESBL)菌株中分离到一个新基因，命名为bla(CTX-M-82)(Ala-40->；Pro)，湖南省产超广谱β-内酰胺酶基因主要为bla(CTX-M)。中国此前从未报告过BLA(CTX-M-15)的高患病率(17.4%)。我们的结果表明，湖南省长沙市的一次BLA(CTX-M)流行是随着针对BLA(CTX-M-14)和BLA(CTX-M-3)优势基因的BLA(CTX-M-15)的出现和传播而演变的。BLA(CTX-M-15)在世界范围内的主导地位可能会蔓延到中国，取代目前流行的基因型别。
The aim of this study was to undertake a survey of the occurrence of CTX-M and SHV extended-spectrum beta-lactamase (ESBL) genotypes in Enterobacteriaceae from Hunan Province, China.Clinical isolates (425) from three major hospitals in Changsha, Hunan Province, were collected between October 2004 and July 2005, and their antimicrobial susceptibilities of the genotype of bla(CTX-M) and bla(SHV) were determined. Random amplified polymorphic DNA was used to characterize the clonality of all of the isolates.The overall rate of ESBL-positive isolates was 33.4% (142/425). The dominant ESBLs were CTX-M types, and were found in 109/142 (76.8%) isolates comprising seven different genera/species, namely Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Enterobacter aerogenes, Citrobacter freundii, Proteus vulgaris and Providencia stuartii. The most common bla(CTX-M) genotypes were bla(CTX-M-14) (47.7%), bla(CTX-M-3) (29.4%) and bla(CTX-M-15) (17.4%). A novel gene derived from bla(CTX-M-15), bla(CTX-M-82) (Ala-40 -> Pro), was identified.The dominant ESBL genotype in Hunan Province was bla(CTX-M). The high prevalence (17.4%) of bla(CTX-M-15) has not previously been reported from China. Our results identify that an epidemic of bla(CTX-M) in Changsha, Hunan Province, has evolved with the appearance and spread of bla(CTX-M-15) against the dominant genotypes bla(CTX-M-14) and bla(CTX-M-3.) The worldwide dominance of bla(CTX-M-15) could be poised to spread to China, displacing the current prevailing genotypes.