ICU分离的大肠埃希菌基因分型及耐药分析

Genotyping of Escherichia coli isolated from ICU and drug resistance situation analysis

目的探讨珠海市人民医院ICU患者分离的30例多重耐药的大肠埃希菌的耐药及基因分型情况,为ICU患者合理使用抗菌药物提供依据。方法通过MIC法分析大肠埃希菌对抗菌药物的敏感性,采用肠杆菌科基因间重复性一致序列(ERIC)-聚合酶链反应(PCR)对药敏实验筛选出多重耐药的大肠埃希菌进行基因分型。结果 ICU共分离30株菌种,分为A型和B2型两个基因型,分别在痰液分离16株(B2型5株),血液9株(B2型7株),肺灌洗液3株,尿液2株(B2型1株)。药敏结果显示B2型13株,对阿莫西林、头孢呋辛、哌拉西林、替卡西林的耐药率均达90%以上。A型17株,对阿莫西林、头孢噻吩、庆大霉素、替卡西林、哌拉西林的耐药率达均达70%以上,B2型的多重耐药率高于A型。结论 B2型菌株表现为多重耐药性且致病性强,主要分布在血液标本中,应该根据ICU患者感染不同基因型的大肠埃希菌来合理调整抗菌药物的使用。

Objective To explore the drug resistance and genotypes in 30 strains of multi-drug resistant Escherichia coli isolated from ICU patients to provide the basis for rational use of antibacterial drugs in ICU patients .Methods The MIC method was a-dopted to analyze the antimicrobial susceptibility of Escherichia coli and the Enterobacteriaceae intergenic repetitive sequence (ERIC)-polymerase chain reaction (PCR) method was adopted to perform the genotyping of multi-drug resistant Escherichia coli screened out by the antimicrobial susceptibility .Results 30 strains of Escherichia coli were isolated from ICU and divided into two genotypes of type A and B2 ,among which 16 strains were isolated in sputum (5 strains of type B2) ,9 strains in blood (7 strains of type B2) ,3 strains in lung lavage fluid and 2 strains in urine (1 strain of type B2) .The drug susceptibility test results showed 13 strains of type B2 and their resistance rates to amoxicillin ,cefuroxime ,piperacillin ,ticarcillin were over 90% .17 strains were type A and their resistance rates to amoxicillin ,cephalothin ,gentamicin ,ticarcillin and piperacillin reached more than 70% .The multi-drug resistance in type B2 was higher than that in the type A .Conclusion Type B2 strain of Escherichia coli shows multi-drug resist-ance and strong pathogenicity and mainly distributes in the blood samples .The use of antibacterial drugs in ICU patients should be reasonably adjusted according to different genotypes of Escherichia coli infection .