摘要目的 对多重耐药克雷伯菌属中喹诺酮类耐药相关基因的分布和变异情况进行分析.方法 连续收集2010年2月至2012年3月南京医科大学附属淮安第一医院住院患者中分离的多重耐药克雷伯菌共20株,用分子鉴定法鉴定菌种,再用聚合酶链反应(PCR)法分析喹诺酮类药物作用靶位基因gyrA与parC,以及可移动遗传元件介导的喹诺酮类耐药基因(qnrA、qnrB、qnrS、qepA、aac (6 ′)-Ⅰ b-cr).结果 本组20株克雷伯菌中,19株为肺炎克雷伯菌,1株为变栖克雷伯菌.20株克雷伯菌均检测到gyrA和parC基因,其中gyrA基因突变率为55.0％ (11/20),parC基因突变率为55.0％(11/20)；aac(6′)-Ⅰ b-cr基因阳性率为50.0％(10/20),qnrA基因阳性率为5.0％(1/20),qnrB基因阳性率为15.0％(3/20).其中6号株与10号株的gyrA与parC基因均为新的变异型(美国GenBank 登录号分别为:JX123016、JX123017与JX144393、JX144394).结论 肺炎克雷伯菌中gyrA和parC基因同时为新的变异型属国内首次报道,该菌对喹诺酮类药物的耐药主要与喹诺酮类耐药决定区突变相关.

abstractsObjective To investigate the distribution and variety of quinolone-resistance genes in a group of multiple resistant Klebsiella.Methods A total of 20 strains of multiple resistant Klebsiella were collected from inpatients in Huai' an First People' s Hospital of Nanjing Medical University during February 2010 and March 2012.Strains were identified by molecular identification,and quinolone target genes (gyrA,ParC) and quinolone-resistance genes mediated by mobile genetic elements (qnrA,qnrB,qnrS,aac (6′)-Ⅰ b-Cr,qepA) were analyzed with polymerase chain reaction (PCR).Results In 20 strains of Klebsiella,19 were Klebsiella pneumonia,and 1 was Klebsiella variicola.gyrA and parC genes were found in all 20 strains,and gyrA mutation was found in 11 strains (55.0％),andparC mutation was also found in 11strains (55.0％).aac(6′)-Ⅰ b-cr was positive in 10 strains (50.0％),qnrA was positive in 1 strain (5.0％),and qnrB was positive in 3 strains (15.0％).gyrA and parC in strain No.6 and No.10 were both novel variants (GenBank registration number:JX123016,JX123017,JX144393,JX144394).Conclusion Quinolone-resistance-determining region plays a key role in resistance to quinolones in this group of Klebsiella,and it is the first report on the emergence of novel variants of gyrA and parC in one Klebsiella pneumonia in China.