山东某院耐碳青霉烯类肠杆菌科细菌临床感染特征及耐药基因分析

Clinical infection characteristics and their drug resistance genes of carbapenem-resistant Enterobacteriaceae in a hospital of Shandong

目的了解济宁医学院附属医院耐碳青霉烯类肠杆菌科细菌(CRE)临床感染特征、药物敏感性及耐药基因分型,为预防和治疗CRE感染及医院多重耐药菌管理提供参考。方法收集CRE临床分离株93株,采用全自动微生物鉴定系统进行细菌鉴定及体外药物敏感性试验,并通过全自动快速微生物质谱检测系统确证菌株。采用简易碳青霉烯类灭活法(sCIM)试验进行碳青霉烯酶表型确证,采用Xpert Carba-R检测并鉴别碳青霉烯酶分型,通过聚合酶链反应(PCR)扩增碳青霉烯酶耐药基因并进行测序分型。结果济宁医学院附属医院CRE主要分离自痰液样本,其次是血液和尿液样本,科室来源主要为重症监护病房。CRE对临床常用的24种抗菌药物均耐药,对替加环素均敏感。sCIM试验检出79株产碳青霉烯酶;Xpert Carba-R检出KPC基因阳性38株、NDM基因阳性31株、IMP基因阳性6株、NDM+KPC基因阳性4株。PCR扩增结果显示,有38株携带KPC耐药基因,31株携带NDM耐药基因,6株携带IMP耐药基因,4株同时携带KPC和NDM耐药基因,未检出VIM及OXA-48耐药基因。结论济宁医学院附属医院CRE临床分离株对多种临床常用抗菌药物耐药,但对替加环素具有良好的体外敏感性;肺炎克雷伯菌碳青霉烯类耐药基因主要为KPC型,大肠埃希菌主要为NDM型;应加强对CRE的监控,防范其在院内的暴发流行。

Objective To investigate the clinical infection characteristics,drug susceptibility and drug resistance genotypes of carbapenem-resistant Enterobacteriaceae(CRE)in the Affiliated Hospital of Jining Medical University,and to provide a reference for the prevention and treatment of CRE infection and the management of multi-drug resistant bacteria.Methods Totally,93 isolates of CRE were collected,bacterial identification and drug susceptibility tests were carried out by VITEK2 Compact automatic microbial identification and drug susceptibility system,and the isolates were confirmed by automatic rapid microbial mass spectrometry.Carbapenemase was confirmed by simplified carbapenem inactivation method(sCIM)phenotype confirmation test.Carbapenemase models were determined and identified by Xpert Carba-R.Carbapenemase resistance gene was amplified by polymerase chain reaction(PCR)and sequenced.Results CRE isolates were mainly isolated from sputum,blood and urine samples.CRE isolates were mainly distributed in intensive care unit.CRE isolates were resistant to 24 commonly used antibiotics and sensitive to tigecycline.Totally,79 isolates were positive for carbapenemase phenotype by sCIM phenotype confirmation test.Xpert Carba-R showed that there were 38 isolates of KPC gene positive,31 isolates of NDM gene positive,6 isolates of IMP gene positive and 4 isolates of NDM+KPC gene positive.A total of 38 isolates carrying KPC resistance genes,31 isolates carrying NDM resistance genes,6 isolates carrying IMP resistance genes and 4 isolates carrying KPC+NDM resistance genes.VIM and OXA-48 resistance genes were not determined.Conclusions CRE in the Affiliated Hospital of Jining Medical University is resistant to many commonly used antibiotics,but it has good drug susceptibility to tigecycline in vitro.The carbapenem-resistant gene of Klebsiella pneumoniae is mainly KPC type,and that of Escherichia coli is mainly NDM type.The surveillance should be strengthened to prevent its outbreak and nosocomial epidemic.