Abstract:

Objective　To investigate the status of Klebsiella pneumoniae carbapenemase (KPC) production and its molecular epidemiological characteristics of Escherichia coli and Klebsiella pneumoniae isolated from nosocomial infection in Xiamen area. Methods　The antimicrobial susceptibility of isolates was assessed by using the VITEK 2 COMPACT 15 automated microbiological analysis system. The screening of carbapenemase phenotypes was performed using the modified Hodge experiments with imipenem as a guideline. The genotypes of KPCs were analyzed by polymerase chain reaction (PCR) and sequencing. The genotypes of Klebsiella pneumoniae and Escherichia coli were detected by pulsed field gel electrophoresis (PFGE). The cluster analysis was performed to investigate whether there was nosocomial dissemination or not. Results　Eighteen strains of Escherichia coli and Klebsiella pneumoniae which produced KPC in Xiamen, were highly resistant to common antibiotics and were sensitive to polymyxin only. The KPC genotype was KPC-2. The results of PFGE showed that 88.9% (16/18) of Klebsiella pneumoniae belonged to 16 genotypes and 11.1% (2/18) of Escherichia coli belonged to 2 genotypes. Conclusions　KPC-2 type Klebsiella pneumoniae in hospital in Xiamen area is resistant to common antibiotics, and there is no regional outbreak. It is necessary to strengthen the monitoring of nosocomial infection.

Key words:

Escherichia coli, Klebsiella pneumoniae, Drug resistance, KPC

摘要：

目的　了解厦门地区医院感染分离的大肠埃希菌及肺炎克雷伯菌产肺炎克雷伯菌碳青霉烯酶（KPC）情况及其分子流行病学特征。方法　通过使用VITEK 2 COMPACT 15型全自动微生物分析系统，评估检测分离株的抗菌药物敏感性；采用改良Hodge实验以亚胺培南为指示药物，对分离菌株进行碳青霉烯酶表型的筛选；采用聚合酶链反应（PCR）、测序分析阳性菌株KPC的型别；使用脉冲场凝胶电泳技术（PFGE）进行分子分型，探讨产KPC的肺炎克雷伯菌和大肠埃希菌基因型，进行聚类分析，探讨是否存在医院内播散。结果　厦门地区分离的18株产KPC的大肠埃希菌和肺炎克雷伯菌对常见的抗生素呈现高度耐药，仅对多黏菌素敏感；KPC基因型为KPC-2型；PFGE结果显示，88.9%（16/18）肺炎克雷伯菌属于多个基因型，11.1%（2/18）大肠埃希菌分别属于2个基因型。结论　厦门地区医院存在院际流行的KPC-2型肺炎克雷伯菌，对常见抗生素耐药，没有发生地区性的暴发流行，需要加强医院感染监测。

关键词:

大肠埃希菌, 肺炎克雷伯菌, 耐药性, 肺炎克雷伯菌碳青霉烯酶