产气肠杆菌氨基糖苷类药物获得性耐药基因研究

Study of acquired aminoglycosides resistance genes in Enterobacter aerogenes

目的研究医院产气肠杆菌临床分离株氨基糖苷类药物获得性耐药机制,了解该细菌对氨基糖苷类药物的耐药性,为临床资料提供参考依据。方法 24株产气肠杆菌分离自2012年1月-2012年12月住院患者,采用VITEK-2Compact分析系统的药敏卡AST-GN13及K-B法测定抗菌药物的敏感性,聚合酶链反应(PCR)检测6种氨基糖苷类修饰酶基因和两种16SrRNA甲基化酶基因。结果 24株产气肠杆菌对头孢替坦100.0%耐药,有16株对头孢曲松的耐药率为66.7%,14株对环丙沙星的耐药率为58.3%;PCR检出氨基糖苷类修饰酶基因aac(3)-Ⅱ1株,阳性率为4.2%,aac(6′)-Ⅰb 6株阳性率为25.0%,其余4种氨基糖苷类修饰酶基因未检出。结论氨基糖苷类修饰酶基因检出阳性率与产气肠杆菌对氨基糖苷类药物的耐药率基本相符。

OBJECTIVE To study the mechanism of acquired aminoglycosides resistance genes in Enterobacter aerogenes isolated from clinical and understand the drug resistance for the bacterial to aminoglycosides, so as to provide reference to clinic. METHODS A total of 24 strains of Enterobacter aerogenes were isolated from the inpatients during Jan. 2012 to Dec. 2012. The antimicrobial susceptibility was detected by VITEK2-compact assay system card AST-GN13 and K-B tests; 6 kinds of aminoglycoside modifying enzyme genes and 2 16SrRNA methyltrans- ferase genes were detected by polymerase chain reaction （PCR）. RESULTS The 24 strains E. aerogenes were all resistant to cefotetan, 16 strains were resistant to cefatriaxone, 14 strains were resistant to ciprofloxacin, and the resistance rates were 100 %, 66.7 % and 58.3 %, respectively. Aminoglycoside modifying enzyme gene aac（3）- Ⅱ and aac（6t） - Ⅰ b were detected in 1 and 6 strains E. aerogenes, the positive rates were 4.2% and 25% ,respectively. The other 4 kinds of aminoglycoside modifying enzyme genes were not detected. CONCLUSION The aminoglycoside modifying enzyme gene positive rate and the E. aerogenes strains on the aminoglycoside drug resistance rate are consistent with the basic.