ERIC-PCR技术在鲍曼不动杆菌基因分型中的应用评估

摘要

目的 了解仁济医院鲍曼不动杆菌的基因同源性,验证肠杆菌科基因间重复序列(ERIC)-聚合酶链反应(PCR)在鲍曼不动杆菌基因分型中的实用性.方法 采用琼脂稀释法检测临床分离的81株鲍曼不动杆菌对临床常用抗菌药物的最低抑菌浓度(MIC)；采用ERIC-PCR对81株鲍曼不动杆菌进行基因分型；使用脉冲场凝胶电泳(PFGE)技术对其中的43株耐亚胺培南鲍曼不动杆菌进一步分型,以PFGE分型为参考标准,验证ERIC-PCR在基因分型中的实用性.结果 81株鲍曼不动杆菌对临床常用的13种抗菌药物普遍耐药,只对米诺环素耐药率最低,为30.9％,其次是亚胺培南,为53.1％,对其他抗菌药物的耐药率均＞60％.81株鲍曼不动杆菌ERIC-PCR分型主要为A、B、C、D、E、F6型,其中A、B、C型为主要的流行株.43株耐亚胺培南鲍曼不动杆菌分型为A型41株(A1型29株,A2型12株)、B型1株、C型1株.PFGE分型将其分为5型,A型34株(A1型31株,A2型3株),B型6株,C、D、E分型各1株.结论 仁济医院鲍曼不动杆菌存在克隆播散,且主要为耐亚胺培南鲍曼不动杆菌.ERIC-PCR分辨力较强,结果可靠,与PFGE结果具有一定的相关性,是一种简便、快捷的基因分型技术.%Objective To investigate the gene homology of Acinetobacter baumannii clinical isolates in Renji Hospital and to demonstrate the role of enterobacterial repetitive intergenic consensus (ERIC)-polymerase chain reaction (PCR) on genotyping of Acinetobacter baumannii.Methods The minimum inhibitory concentrations (MIC) of common clinical antibiotics against 81 isolates of Acinetobacter baumannii were determined by agar dilution method.ERIC-PCR was used to type 81 isolates of Acinetobacter baumannii.Pulsed-field gel electrophoresis (PFGE) as reference standard was used to further type 43 imipenem-resistant Acinetobacter baumannii.The practicability of ERIC-PCR was verified.Results The 81 isolates ofAcinetobacter baumannii were commonly resistant to 13 antibiotics.The lowest resistant rate was 30.9％ for polymyxin,the second was 53.1％ for imipenem,and the others were all ＞60％.The 81 isolates of Acinetobacter baumannii were classified into 6 types by ERIC-PCR,named genotype A,B,C,D,E and F.There mainly were A,B and C genotypes.The 43 imipenem-resistant Acinetobacter baumannii belonged to 3 genotypes,including genotype A had 41 isolates (29 isolates of type Al and 12 isolates of type A2),genotype B had 1 isolate,and genotype C had 1 isolate.There mainly were 5 PFGE pulsotypes for the 43 isolates,pulsotype A had 34 isolates (31isolates of type A1 and 3 isolates of type A2),pulsotype B had 6 isolates,and C,D and E types had 1 isolate for each.Conclusions There has been clonal spread of Acinetobacter baumannii among patients in the hospital,which mainly were imipenem-resistant Acinetobacter baumannii.The ERIC-PCR is a useful and expeditious method for genotyping of Acinetobacter baumannii,and the results are correlated with those of PFGE.