医院多药耐药铜绿假单胞菌菌株亲缘关系研究

Genetic Relationship of Multi-drug Resistant Pseudomonas aeruginosa

目的分析一所三级教学医院临床分离的20株多药耐药铜绿假单胞菌(MDR-PAE)的菌株亲缘关系。方法收集2009年2月-2010年4月,从医院住院患者分离出的MDR-PAE 20株,采用聚合酶链反应(PCR)及序列分析方法对42种β-内酰胺酶基因、氨基糖苷类修饰酶基因、甲基化酶基因、可移动遗传元件遗传标记以及毒力因子基因进行检测,并将检测结果作聚类分析以探讨MDR-PAE的菌株亲缘关系。结果 20株MDR-PAE中,TEM、PER、DHA、OXA-10群等4种β-内酰胺酶基因的阳性检出率分别为25.0%、20.0%、5.0%及20.0%,膜孔蛋白编码基因oprD2缺失率为100.0%;tnp513/ISCR1I、S26I、Spa7及intⅠ1等4种转座子、插入序列和整合子遗传标记基因的阳性检出率分别为20.0%、20.0%、30.0%及30.0%;氨基糖苷类修饰酶基因aac(3)-Ⅱ、aac(6′)-Ⅰb、aac(6′)-Ⅱ、ant(3″)-Ⅰ及ant(2″)-Ⅰ的阳性检出率分别为40.0%、10.0%、20.0%、15.0%及10.0%,甲基化酶基因rmtB的阳性率为15.0%;以42种β-内酰胺酶基因、氨基糖苷类修饰酶基因、甲基化酶基因和可移动遗传元件遗传标记以及毒力因子基因作检测结果的样本聚类分析显示,编号为No.2、8等2株,4、5、6等3株及1、10、11、12、14、15、20等7株为三群克隆传播。结论多药耐药铜绿假单胞菌株在该院不同科室间存在3群克隆传播株,加强对MDR-PAE耐药基因检测并对结果进行聚类分析对其医院感染的实时监测很有意义。

OBJECTIVE To analyze the genetic relationship of multidrug-resistant Pseudomonas aeruginosa（MDR-PAE） isolated from a tertially care level teaching hospital.METHODS Totally 20 multi-drug resistant P.aeruginosa（MDR-PAE） strains were isolated from patients hospitalized from Feb 2009 to Apr 2010,42 related genes were analyzed by PCR and verified by DNA sequencing,which included drug resistance against β-lactam and porin genes,aminoglycosides modification enzyme and methylase genes and transposons,insert sequence and integrons considered as genetic marker.The results of detection were analyzed with cluster analysis to confirm the genetic relationship of all strains.RESULTS In 20 MDR-PAE strains,the positive rate of TEM,PER,DHA and OXA-10 cluster genes was 25.0%,20.0%,5.0% and 20.0%,respectively,and the deletion rate of porin gene was 100.0%.The positive rate of tnp513/ISCR1,IS26,ISpa7 and intⅠ1 was 20.0%,20.0% and 30.0%.Meanwhile,40.0%,10.0%,20.0%,15.0% and 10.0% isolates were detected to carry aac（3）-Ⅱ,aac（6′）-Ⅰb,aac（6′）-Ⅱ,ant（3″）-Ⅰ,and ant（2″）-Ⅰ,and 15.0% to carry rmtB,respectively.The results of genetic clustering analysis showed that No.2,8 and 4,5,6 and 1,10,11,12,14,15,20 strains belonged to three cluster cloning.CONCLUSION There are 3 cluster cloning strains of MDR-PAE in this hospital which transmitted in different departments,and it is meaningful to strengthen to detect drug resistant genes of MDR-PEA and make cluster analysis for real-time monitoring nosocomial infection.