临床分离肺炎克雷伯菌Ⅰ整合子分布及其与qnr基因关系研究

目的 了解临床分离肺炎克雷伯菌中qnr基因和Ⅰ类整合子基因的分布及其耐药特征.方法 采用PCR法对45株耐环丙沙星肺炎克雷伯菌进行qnrA、qnrB、qnrS基因筛查并测序,用PCR法检测qnr阳性菌株Ⅰ类整合子基因,并采用SPSS 13.0和Whonet 5.4软件分析药敏结果及比较.结果 45株肺炎克雷伯菌中,24株(51.1％)细菌检出qnrS基因,未检出qnrA和qnrB基因.20株qnr阳性菌株同时携带Ⅰ类整合子基因.qnr阳性菌株Ⅰ类整合子基因携带率显著高于阴性菌株,qnr阳性菌株对阿米卡星、妥布霉素、亚胺培南、哌拉西林/他唑巴坦及头孢哌酮舒巴坦的敏感性较高.结论 肺炎克雷伯菌对氟喹诺酮类抗菌药物耐药主要由qnrS引起,qnr阳性株同时携带Ⅰ类整合子,导致呈现多重耐药性,加强临床耐药监测对控制多重耐药传播有着重要的意义.

Distribution and relationship between class I integron and qnr gene in clinical Klebsiella pneumoniae isolates

Objective To investigate the distribution and resistant characteristics of the qnr gene and class I integrons in clinical Klebsiella pneumoniae isolates.Methods The qnrA,qnrB and qnrS genes and class I integrons were detected in 45 Klebsiella pneumoniae isolates by PCR.And the PCR products were sequenced subsequently.Statistical analysis and the susceptibility data were determined by SPSS 13.0 and Whonet 5.4.Results Among the 45 Klebsiella pneumoniae isolates,there were 24 strains with qnrS gene(51.1%).No qnrA and qnrB genes were detected.20 qnr-positive strains carried the class I integron gene.The rate of class I integron-carrying qnr-positive strains were significantly higher than the negative ones.The qnr-positive strains were more sensitive to amikacin,tobramycin,imipenem,piperacillin/tazobactam and cefoperazone/sulbactam.Conclusion The fluoroquinolone-resistant Klebsiella pneumoniae was mainly caused by qnrS gene.The qnr-positive strains often contain the Class I integron,which result in the multi-drug resistance of Klebsiella pneumoniae.So we should strengthen surveillance of the control on Klebsiella pneumoniae resistance to prevent the spread of multidrug-resistance.