阴沟肠杆菌临床分离株armA基因分布与分子分型研究

Study on distribution and molecular typing of gene armA of clinical isolated Enterobacter cloacae in a hospital

目的调查某医院阴沟肠杆菌临床分离株的耐药性和arm A基因分布情况,探索arm A阳性菌株与耐药性的关系及其分子分型特征。方法采用微量肉汤稀释法对51株临床分离的阴沟肠杆菌进行药敏试验;荧光定量PCR方法检测16S rRNA甲基化基因arm A;脉冲场凝胶电泳试验(PFGE)分析arm A阳性菌株间的亲缘关系。结果阴沟肠杆菌临床分离株对阿米卡星和庆大霉素的耐药率分别为39.2%和54.9%,arm A基因阳性率为23.5%,arm A阳性菌株对阿米卡星和庆大霉素均耐药;12株携带arm A基因菌株主要分为5型,无明显优势菌株。结论产16S rRNA甲基化酶arm A的阴沟肠杆菌菌株对氨基糖苷类药物耐药,应加强对该基因监测,合理指导临床抗生素应用。

Objective To investigate the drug resistance of clinical isolated Enterobacter cloacae and prevalence of gene arm A,and to explore the relationship between positive stains,drug resistance and molecular typing. Methods Broth micro-dilution method was used to determine drug resistance of 51 strains of clinical isolated Enterobacter cloacae. The arm A genes were detected by fluorogenic quantitative PCR. Pulsed-field gel electrophoresis（ PFGE） was used to analyze the homology of arm A positive strains. Results 23. 5% of the isolates were arm A positive and the resistance rates of the strains to gentamyein and amikacin were 39. 2% and 54. 9%,respectively. All of the Enterobacter cloacae isolates harboring arm A gene were resistant to aminoglycosides. 5 different types were observed by PFGE,none was advantage type. Conclusion The study showe that arm A gene is prevalent in Enterobacter cloacae which could lead to resistant to aminoglycosides. It is necessary to reinforce gene surveillance and guide clinical use of antibiotics.