临床分离鲍曼不动杆菌耐药性及qnr基因检测

目的了解临床分离鲍曼不动杆菌中qnr基因和ESBLs基因的分布及其耐药特征。方法采用PCR法对115株鲍曼不动杆菌进行qnrA、qnrB、qnrS基因筛查,并用PCR法检测qnr阳性菌株SHV、TEM、CTX-M-14及CTX-M-3型ESBLs基因;用琼脂对倍稀释法测定15种抗菌药物对qnr阳性株的MIC值。结果115株鲍曼不动杆菌中,2株(1.74%)细菌检出qnrB基因;qnr阳性菌株同时检出SHV、CTX-M-14、TEM、CTX-M-3型ESBLs基因。1株qnr阳性菌株对4种喹诺酮类耐药,1株对左氧氟沙星及莫西沙星中介,对环丙沙星和洛美沙星耐药;2株阳性菌除对亚胺培南和头孢哌酮/舒巴坦敏感外,对其他的β-内酰胺类抗菌药物均耐药。结论临床分离鲍曼不动杆菌中存在qnrB基因,qnr阳性株同时含有ESBLs基因,且呈多重耐药,临床应加强监测。

Detection of qnr gene and drug resistance in clinical isolates of Acinetobacter baumannii

Objective To detect the distribution of qnr gene and ESBLs gene,and the drug resistance characteristics in clinical isolates of Acinetobacter baumannii.Methods Screening of qnrA,qnrB and qnrS genes were carried out by PCR amplification in 115 Acinetobacter baumannii strains.The MIC values of antimicrobial agents against qnr-positive strains were measured by two-fold agar dilution method.The ESBLs genes typed SHV,TEM,CTX-M-14and CTX-M-3 in qnr-positive strains were detected.Results Two out of 115(1.74%)Acinetobacter baumannii strains were qnrB gene positive.SHV,TEM,CTX-M-14 and CTX-M-3 ESBLs gene were detected in qnr-positive strains simultaneously.One qnrB positive strain Was resistant to 4 kinds of quinolones.Another one was intermediate to levofloxacin and moxifloxacin and resistant to ciprofloxacin and lomefloxacin.Two qnrB gene positive strains were sensitive to imipenem and cefoperazone/sulbactam,But resistant to the other β-lactam antibiotics.Conclusions qnrB gene was found in clinical isolates of Acinetobacter baumannii.qnr gene positive strains were multi-drug resistant due to producing ESBLs simultaneously.Clinical monitoring should be strengthened.