临床分离鲍曼不动杆菌耐药表型和质粒介导喹诺酮类耐药基因研究

Study on drug-resistant phonotype and plasmid-mediated quinolone resistance genes in Acinetobacter baumannii isolates

目的:对医院分离出的鲍曼不动杆菌耐药谱进行调查,探求鲍曼不动杆菌中质粒介导对喹诺酮类药物耐药基因(PMQR)携带情况,给临床感染性疾病治疗提供参考。方法:采用VITEKT-2 compact全自动细菌鉴定及药敏系统对菌株进行鉴定和药敏检测,采用PCR法检测细菌是否携带PMQR基因(qnrA、B、C、D、S、aac(6')-Ib和qepA),随机选取每种耐药基因的PCR产物进行测序分析。病原菌的药敏结果采用WHONET 5.6软件分析。结果:近两年来从临床标本中一共检出152株鲍曼不动杆菌,药敏结果显示鲍曼不动杆菌对喹诺酮类和其他抗菌药物的耐药性有逐年递增之势。PCR检测结果显示29.6%(45/152)菌株携带aac(6')-Ib,1.3%(2/152)菌株携带qnrB,质粒上的qnrA、C、D、S和外排泵qepA基因产物并未检测出。结论:本地区鲍曼不动杆菌对临床常用抗菌药物的耐药性强,PMQR携带率较低。

AIM:To investigate drug resistance of Acinetobacter baumannii strains isolated in the hospital from 2018 to 2019,and explore plasmid-mediated delivery of quinolones resistance genes(PMQR)in Acinetobacter baumannii,to provide references for the clinical therapy of infections and to analysis the genetic mechanisms of resistance by aid of molecular methods.METHODS:Bacteria were identified by VITEK-2 compact System,the results of antibiotics susceptibility test was determined by using microdilution method MIC.We amplified genes of qnrA,B,C,D,S,aac(6')-Ib and qepA on plasmid by PCR,and PCR products of each resistant gene for sequencing analysis were random selected.We analyzed the results of antibiotics susceptibility of 152 clinical isolates based on WHONET 5.6 software.RESULTS:In the past two years,152 strains of Acinetobacter baumannii have been detected from clinical specimens.The antibiotics resistance rate of Acinetobacter baumannii isolates was an increasing trend year by year.PCR indicated that some strains of Acinetobacter baumannii have products of aac(6')-Ib and qnrB gene,29.6%(45/152)strains carrying aac(6')-Ib and 1.3%(2/152)strains carrying qnrB;there were no products of qnrA,C,D,S and qepA genes on plasmid.CONCLUSION:The current drug-resistance rate among Acinetobacter baumannii strains in Hefei to common antibiotics is high,and PMQR carrying rate is low.