37株枸橼酸杆菌的耐药性及PFGE分型分析  

Study on drug resistance and molecular characteristics of Citrobacter

作　　者：白莉[1] 汪永禄[2] 金东[1] 白雪梅[1] 周海健[1] 刘燕[2] 陶勇[2] 石志峰[2] 叶长芸[1] 徐建国[1] 

机构地区：[1]中国疾病预防控制中心传染病预防控制所传染病预防控制国家重点实验室,北京102206 [2]安徽省马鞍山市疾病预防控制中心

出　　处：《疾病监测》2009年第5期316-318,共3页Disease Surveillance

基　　金：973课题:新发传染病病原体分离;鉴定技术的前期探索研究(No.2005CB522905)

摘　　要：目的了解食品及患者来源的37株枸橼酸杆菌的耐药性、毒力基因携带及PFGE的分型情况。方法运用K-B法选择15种抗生素进行药敏试验;以PCR方法检测志贺样毒素(stx1和stx2)、紧密素基因(eae)及溶血素(hly)4种毒力基因;用脉冲场凝胶电泳(pulse field gel electrophoresis,PFGE)方法进行同源性分析。结果37株枸橼酸杆菌中,25株为杨氏枸橼酸杆菌,11株为弗劳地枸橼酸杆菌,1株为布雷克氏枸橼酸杆菌。分离菌株对大多数抗生素敏感,但对头孢噻吩100%耐药。其毒力基因检测均为阴性。PFGE结果发现不同菌株带型差异较大。其中5株食品来源,1株为人来源的杨氏枸橼酸杆菌同为MAS007型,具有流行病学相关性。结论该地区枸橼酸杆菌主要以杨氏枸橼酸杆菌为主;部分菌株具有多重耐药,应加强菌株的耐药性监测;脉冲场凝胶电泳对枸橼酸杆菌有较好的分型能力,有助于分析追踪疫情和来源;患者可能存在食源性感染,应引起疾控部门的重视。Objective To investigate the drug resistance, the virulence genes and the pulse field gel electrophoresis （PFGE） patterns of 37 strains of Citrobacter isolated from diarrhea patients and food. Methods The Kirby-Bauer disk diffusion test was conducted for Citrobacter isolates to test their resistance to 15 antibiotics; the detection of virulence genes （stxl, stx2, hly and eaeA ） of these isolates was performed by routine PCR assay. Homology analysis was performed by PFGE. Results Among 37 strains of Citrobacter, 25 strains were C. youngae, 11 strains were C. freundii and 1 strain was C. braakii. These Citrobacter isolates were sensitive to most antibiotics, but resistant to cephalothin （ 100% ）. The results of virulence genes detection were negative for all the isolates. PFGE analysis revealed that the 37 strains belonged to 29 different patterns. The patterns of 6 strains of C. youngae （ 5 from food, 1 from patient） were same （MAS007）, which had epidemiological link. Conclusion The predominating strains of Citrobacter was C. youngae in the area surveyed. Some of the Citrobacter isolates were multi-drug resistant. PFGE is effective for the subtyping of Citrobacter strains, which is favorable for the tracing of epidemic source. Diarrhea patients might have food borne infection of Citrobacter, and more attention should be paid to it.

关 键 词：枸橼酸杆菌 耐药性 脉冲场凝胶电泳 

分 类 号：R446.5[医药卫生—诊断学] R450[医药卫生—临床医学]