Objective To study the distribution and homology analysisof transposons genes Tn2006 and Tn2008 of carbapenem-resistant Acinetobacter baumannii (CRAB) and provide evidence for nosocomial infection control.Methods A total of 91 non-duplicated Acinetabacter baumannii strains resistant to carbapenemases were collected.The transposons Tn2006 and Tn2008 were detected by PCR amplification and the positive products were sequenced.The repetitive extragenic palindromic PCR (REP-PCR) was used to analyze the homology of 91 CRAB isolates:23 strains was classified by multilocus sequence typing (MLST) technique and minimum spanning tree was analyzed by Bio-Numerics Software.Results Of the 91 CRAB strains tested,Tn2006 was positive in 40 isolates and Tn2008 was all negative.The 91 clinical CRAB isolates were divided into seven types named genotype A-G by REP PCR.Among them,genotype A had 79 strains,genotype B had four strains,genotype C,D,and F had two strains,and the rest had only one strain each.Genotype A included two subtypes,named A1 and A2,which had 46 strains and 33 strains respectively.Strains with genotype A existed in every hospital included in this study.Eight genotypes were revealed among 23 CRAB by MLST:ST92 (9 strains),ST195(5 strains),ST365(3 strains),ST138(2 strains),ST75(1 strains),ST381(1 strains),and two new genotypes (STn1,1-15-3-2-2-56-3;STn2,1-81-3-2-2-3-3).Conclusion There was prevalence of the same clones of these clinical isolated CRAB strains in this area,and genotype A was the major prevalence type.These strains were transmitted mainly by the transposons of Tn2006.ST92 and STI95 were the dominant STs of CRAB.%目的 探讨耐碳青霉烯类药物鲍曼不动杆菌的转座子基因Tn2006、Tn2008分布及其同源性,为医院感染控制提供实验室依据.方法 收集91株对碳青霉烯类药物耐药的非重复鲍曼不动杆菌,PCR检测转座子基因Tn2006和Tn2008,并对扩增产物进行测序及BLAST分析;采用重复序列引物聚合酶链反应(REP-PCR)分析CRAB同源性;采用多位点序列分型(m-ultilocussequence typing,MLST)技术对23株CRAB进行同源性分析,利用BioNumerics软件分析最小生成树.结果 在检测的91株CRAB中,40株菌Tn2006基因阳性,Tn2008基因均为阴性;利用REP-PCR方法可将91株CRAB分为A、B、C、D、E、F和G 7个型别,菌株数分别为79株、4株、2株、2株、1株、2株和1株,A型又分为A1和A2两个亚型,分别为46株和33株,所有被检测医院均出现A型菌株;利用MLST分型方法可将23株CRAB分为8个序列型别(ST型),其中ST92型9株、ST195型5株、ST365型3株、ST138型2株、ST75型和ST381型各1株,发现2个新STs型,即STnl(1-15-3-2-2-56-3)和STn2(1-81-3-2-2-3-3).结论 本地区临床分离CRAB存在克隆流行,以A型为主,主要通过转座子Tn2006进行传播,ST92和ST195是本地区CRAB主要ST分型.
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