携qnrA耐药基因阴沟肠杆菌的分子流行病学研究

Molecular Epidemiology of Enterobacter cloacae with qnrA gene in Shenzhen City

目的了解深圳地区临床分离的qnrA基因阳性阴沟肠杆菌的分子流行病学特征。方法采用PCR和产物直接测序法,检测58株临床分离阴沟肠杆菌的qnrA基因,脉冲场电泳进行菌株的DNA分型。结果11株阴沟肠杆菌中检出qnrA基因,其中甲医院6株、乙医院5株;前者可分为A和B 2个克隆系,A系包括3个相同和1个密切相关克隆,B系包括2个相同的克隆;后者5株菌间无相同或密切相关克隆。结论携qnrA基因阴沟肠杆菌的流行不仅存在散发模式,而且存在克隆株医院感染暴发的模式,应加强其医院感染的监控和分子流行病学研究。

OBJECTIVE To investigate the molecular epidemiology of Enterobacter cloacae （ECL） with qnrA gene. METHODS Fifty eight isolates of ECL from Shenzhen city were investigated for qnrA gene with PCR and direct sequencing. Pulsed field gel electrophoresis （PFGE） genotype, antibiograms and epidemiological data were used to determine the similarities of these isolates. RESULTS Eleven isolates from two hospitals were qnrA positive. PFGE revealed the 6 isolates from hospital A were classified into two clonal lineages （clusters Ⅰ comprised 4 isolates, cluster Ⅱ comprised 2 isolates）. There were no closely related or indistinguishable isolates among the 5 isolates and from hospital B. The antibiograms of the isolate from the same clonal lineage were similar and differed from other clonal lineage. CONCLUSIONS There is an outbreak of E. cloacae with qnrA in hospital A. Hospital acquired infection surveillance and infection control measures must be reinforced.