亚胺培南耐药大肠埃希菌耐药基因型检测  

Detection of resistance genotype in carbapenem-resistance Escherichia coli

作　　者：蒯守刚[1] 裴豪[1] 陈燕燕[1] 刘君[1] 张时良[1] 戴亚新[1] 

机构地区：[1]无锡市传染病医院检验科,江苏无锡214005

出　　处：《检验医学》2011年第10期653-657,共5页Laboratory Medicine

摘　　要：目的研究临床分离的2株亚胺培南耐药的大肠埃希菌分子耐药机制。方法通过琼脂稀释法检测亚胺培南耐药的大肠埃希菌对多种抗菌药物的敏感性,采用肠杆菌科基因间重复性一致序列(ERIC)-聚合酶链反应扩增分析(PCR)对耐药菌株进行同源性分析,采用特异性PCR和序列分析、接合试验、质粒提取和质粒消除试验检测耐药菌株的分子耐药机制。结果大肠埃希菌对包括碳青霉烯类和喹诺酮类在内的多种抗菌药物耐药,同源性分析显示2株菌株属于同一克隆型,PCR和序列分析显示耐药株菌携带KPC-2、qnrA、TEM-1和I类整合酶基因并且伴有外膜蛋白OmpK36基因的缺失,质粒提取和质粒消除试验证实KPC-2和I类整合酶基因定位于约54 kb质粒。结论大肠埃希菌中出现质粒型碳青霉烯酶基因KPC-2,并且同时携带其他耐药相关基因,表现为多重耐药,KPC-2合并外膜蛋白缺失是大肠埃希菌对碳青霉烯类耐药主要机制。Objective To study the molecular resistance mechanism of 2 isolates of carbapenem-resistance Escherichia coli. Methods Agar-dilution was used to detect the sensitivities of carbapenem-resistance Escherichia coli to antibiotics.Enterobacterial repetitive intergenic consensus polymerase chain reaction（ERIC-PCR） was performed to analyze the homology of carbapenem-resistance Escherichia coli.Specific PCRs and DNA sequencing,conjugation experiments,plasmid DNA extraction and elimination of plasmid from isolates were performed to confirm molecular mechanism of carbapenem-resistance. Results Two clinical isolates were resistant to carbapenems,fluoroquinolones and carbapenem antimicrobial agents.ERIC-PCR analysis showed that 2 isolates belonged to identical genotype.PCRs and DNA sequence analysis confirmed that the isolates contained KPC-2,qnrA and I-integrase gene associated with deficiency of OmpK36（outer membrane protein K36） gene.Plasmid DNA extraction and elimination of plasmid from 2 isolates indicated that KPC-2 and I-integrase gene encoded on a 54 kb plasmid.Conclusions Multiple drug-resistant Escherichia coli were encoded KPC-2 carbapenemase gene and other drug-resistant genes.The production of KPC-2 carbapenemase and deficiency of OmpK36 are the main resistance mechanism of carbapenem in Escherichia coli.

关 键 词：大肠埃希菌 碳青霉烯类 Β-内酰胺酶类 耐药 微生物敏感性试验 

分 类 号：R446.5[医药卫生—诊断学]