携带bla_(KPC-2)型碳青霉烯酶基因泛耐药肺炎克雷伯菌对喹诺酮类耐药机制研究  

Study on mechanisms of quinolones resistance in pan-resistant Klebsiella pneumoniae harboring bla_(KPC-2) type carbapenemase gene

作　　者：黄支密[1] 夏守慧[1] 沈娟[1] 周芸[1] 杨海燕[1] 邹玉秀[1] 杨伟平[1] 糜祖煌[2] 朱健铭 

机构地区：[1]解放军第98医院检验科,浙江湖州313000 [2]无锡新区虎马生物信息工作室无锡市克隆遗传技术研究所,江苏无锡214026 [3]杭州市余杭区中医院检验科,浙江杭州311106

出　　处：《中华医院感染学杂志》2015年第8期1684-1686,1692,共4页Chinese Journal of Nosocomiology

基　　金：杭州市科技局科技基金资助项目(20110833B48)

摘　　要：目的了解临床分离的携带blaKPC-2型碳青霉烯酶基因泛耐药肺炎克雷伯菌对喹诺酮类药物的耐药机制,为临床治疗提供参考依据。方法在2008年11月-2009年7月从住院患者中分离19株携带blaKPC-2型碳青霉烯酶基因泛耐药肺炎克雷伯菌,采用聚合酶链反应(PCR)及序列分析的方法分析两种喹诺酮类药物作用靶位编码基因(gyrA、parC)和5种质粒介导的喹诺酮类耐药相关基因。结果 19株携带blaKPC-2型碳青霉烯酶基因泛耐药肺炎克雷伯菌gyrA和parC基因PCR扩增均阳性,1株(5.3%)aac(6′)-Ⅰb-cr基因阳性,qnrA、qnrB、qnrS和qepA基因均阴性;序列分析结果表明,19株gyrA和parC基因均发生突变,分别导致gyrA基因喹诺酮耐药决定区(QRDR)出现两个位点错义突变,导致第83位丝氨酸(Ser)被异亮氨酸(Ile)取代、第87位天冬氨酸(Asp)被甘氨酸(Gly)取代,parC基因QRDR出现1个位点错义突变,导致第80位丝氨酸被异亮氨酸取代。结论染色体介导的耐药机制仍是临床分离的携带blaKPC-2型碳青霉烯酶基因泛耐药肺炎克雷伯菌对喹诺酮类药物耐药主要机制。OBJECTIVE To investigate the resistant mechanism of quinolones in clinically isolated pan-resistant Klebsiella pneumoniae harboring blaKPC-2type carbapenemase gene,so as to provide reference for clincial treatment.METHODS Nineteen strains of pan-resistant Klebsiella pneumoniae harboring blaKPC-2type carbapenemase gene were isolated from the inpatients between Nov.2008 and Jul.2009.Drug target genes to quinolones（gyrA,parC）and quinolone-resistance genes mediated by plasmid qnrA,qnrB,qnrS,qepA,aac（6′）-Ⅰb-cr were analyzed by PCR and verified by DNA sequencing.RESULTS Of the 19 strains tested,the positive rate of genes of gyrA,parCand aac（6′）-Ⅰb-cr were 100.0%,100.0% and 5.3%（1/19）,respectively.The rest 4kinds of genes were all tested negative.Of the 19 strains tested,the double-point mutations and amino acid replacements（Ser83→Ile,Asp87→Gly）were found in quinolone resistance-determining region（QRDR）of gyrA,and the single-point mutation and amino acid replacement（Ser80→Ile）were found in QRDR of parC.CONCLUSIONChromosome-mediated target mutations still play important roles in pan-resistant Klebsiella pneumoniae harboring blaKPC-2type carbapenemase gene resistant to quinolones.

关 键 词：肺炎克雷伯菌 喹诺酮类耐药 blaKPC-2型基因 

分 类 号：R378.996[医药卫生—病原生物学]