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- 2015
肠杆菌科细菌中PER型超广谱β-内酰胺酶的基因检测及遗传特征分析
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Abstract:
目的 了解临床分离的肠杆菌科细菌中产PER型超广谱β-内酰胺酶(ESBLs)基因类型，探讨其流行病学特征及可能的耐药传播机制。 方法 收集2009年6月—2014年1月上海交通大学医学院附属瑞金医院临床标本分离到的对头孢他啶、头孢噻肟和头孢吡肟耐药的肠杆菌科细菌共254株，应用PCR技术扩增PER基因并测序确定基因型；对PER阳性菌株进行接合试验，同时利用脉冲场凝胶电泳（PFGE）对其进行流行病学分析，并扩增PER基因上下游序列。 结果 临床分离的肠杆菌科细菌中共检出14株携带PER基因，包括PER-1和PER-4两种类型。仅2株奇异变形杆菌接合成功，接合质粒属于IncA/C型质粒。9株PER阳性奇异变形杆菌PFGE共分为7个型别。最常见的肠杆菌科细菌基因环境为ISCR1-blaPER-gst-abct，2株产PER-1型ESBLs的奇异变形杆菌基因环境为ISPa12-blaPER-gst-like-ISPa13。 结论 PER基因可存在于多种临床分离的肠杆菌科细菌中。PER基因上游环境多以ISCR1结构为主，该结构在国内PER基因的流行扩散中可能扮演着重要的角色。
： Objective To investigate genotypes, epidemiological characteristics, and possible transmit mechanisms of resistance of PER type extended-spectrum β-lactamase in clinical Enterobacteriaceae isolates. Methods A total of 254 clinical isolates of Enterobacteriaceae with resistance to ceftazidime, cefotaxim, and cefepime were collected from June, 2009 to January, 2014 in Ruijin Hospital, Shanghai Jiao Tong University School of Medicine. The blaPER was identified by the PCR and sequencing. Conjugation experiments were performed for blaPER-positive strains and epidemiological analysis was conducted by the pulsed field gel electrophoresis (PFGE). The upstream and downstream sequences of PER gene were amplified by the PCR. Results A total of 14 clinical Enterobacteriaceae isolates carried the blaPER, including PER-1 type and PER-4 type. Two P. mirabilis isolates were successfully transferred by IncA/C conjugative plasmid. Nine isolates of blaPER-positive P. mirabilis showed 7 different PFGE patterns. The most common genetic environment of Enterobacteriaceae was ISCR1-blaPER-gst-abct and the genetic environment of 2 blaPER-positive P. mirabilis were ISPa12-blaPER-gst-like-ISPa13. Conclusion The blaPER was detected among a variety of clinical Enterobacteriaceae isolates. The upstream genetic environment of blaPER is given priority to the genetic environment with ISCR1 element, which may play an important role in the transmission of Chinese blaPER gene
