中文摘要：

为调查多重耐药基因cfr在广东地区猪源肠球菌中的流行特点及分离株对临床常用药物的耐药情况,本研究通过对临床分离的8株携带cfr基因的肠球菌进行最小抑菌浓度（MIC）测定,脉冲凝胶电泳（PFGE）分型和southern杂交定位,确定分离株的耐药表型和cfr基因在肠球菌中的传播方式.研究表明,8株菌对氟苯尼考、庆大霉素和红霉素耐药率均为100％;对四环素、环丙沙星和利福平的耐药率高达75.0％以上.PFGE结果显示在同一猪场分离的28株cfr阳性肠球菌共有8种不同的PFGE谱型,表明cfr基因在同一猪场中存在克隆传播的现象.Southern杂交结果显示,cfr基因在6株菌中定位于20kb～50kb的质粒.本研究为临床制定合理措施控制cfr快速传播提供实验依据.

英文摘要：

To investigate the epidemiology and dissemination mechanism of multi-resistant gene cfr in Enterococcus spp.from animal origin in Guangdong province,the minimum inhibitory concentrations （MIC） were determined in eight isolates of cfr gene positive Enterococcus spp.with distinct PFGE profiles and the location of cfr gene was detected by southern blot.The results showed that eight isolates were all resistant to florfenicol,gentamycin and erythromycin,and the resistant rate of these isolates to tetracycline,ampicillin,ciprofloxacin and rifampicin were over 75.0％.PFGE analysis showed that certain isolates from the same pig farm displayed the same PFGE type,suggesting the existence of cloning spread of cfi-positive Enterococcus spp.Southem blot displayed that the cfr gene was located in plasmids with size ranging from 20 kb to 40 kb in the other six isolates.