多重耐药大肠埃希菌菌株氯霉素耐药相关基因研究

Study on the Genes of Chloramphenicol Resistance in Multi-drug-resistant Strains of Escherichia coli

目的了解多重耐药大肠埃希菌（ECO）对氯霉素的耐药机制。方法采用PCR法检测20株多重耐药ECO菌氯霉素耐药基因（catB，cmlA）。结果catB基因阳性3株（阳性率15％），cmlA基因阳性7株（阳性率35％）。一株catB基因PCR产物经DNA测序并翻译为氨基酸序列与已在美国国立生物信息中心[NCBI]登录的catB基因序列比对，结果为与大肠埃希菌CATB3[登录号：ABP35557]序列98％（88／89）相同，能判断为新亚型。结论该组多重耐药ECO菌对氯霉素耐药与携带catB，cmlA基因相关。

Objective To investigate mechanisms of chloramphenicol resistance in multi-drug-resistant strains of Es- cherichia coll. Methods The genes（catB,cmlA） of chloramphenicol resistance were detected by polymerase chain reaction （PCR）. Results In 20 strains,3 strain carried catB,7 strains cmlA. There were changes of aminoacids in the sequence of catB of one of the 20 strains,significant difference was found from the others that landed in GenBank,which identified it- self as new subtype. Conclusion The chloramphenicol resistance mechanisms of the ECO are catB and cmlA related.