质粒介导铜绿假单胞菌对喹诺酮类耐药机制的研究

发布时间：2019-05-24 20:48

【摘要】：目的探讨铜绿假单胞菌临床分离株中是否存在质粒介导喹诺酮类耐药(PMQR)机制。方法收集2010年1-12月中山大学附属第三医院临床分离的无重复铜绿假单胞菌256株,采用微量肉汤稀释法测定环丙沙星最低抑菌浓度(MIC),应用PCR方法扩增PMQR基因qnrA、qnrB、qnrC、qnrD、qnrS、aac(6′)-Ib-cr、qepA,并对PCR阳性产物进行测序分析以确定基因亚型。结果 256株铜绿假单胞菌对环丙沙星的耐药株和敏感株分别为65株和180株,MIC50和MIC90分别为0.5μg/ml、16μg/ml;全部菌株中只有1株检测到qnrA基因,其PCR阳性产物经测序证实为qnrA1亚型,环丙沙星对该菌株的MIC为2μg/ml;未检测到qnrB、qnrC、qnrD、qnrS、aac(6′)-Ib-cr和qepA基因。结论国内首次从铜绿假单胞菌中发现qnrA1基因,该耐药基因介导细菌对环丙沙星低水平耐药,PMQR尚未成为铜绿假单胞菌对喹诺酮类耐药的主要机制之一。
[Abstract]:Objective to investigate the mechanism of plasmid mediated quinolone resistance (PMQR) in clinical isolates of Pseudomonas aeruginosa. Methods 256 strains of Pseudomonas aeruginosa isolated from the third affiliated Hospital of Sun Yat-sen University from January to December 2010 were collected. The minimum inhibitory concentration of ciprofloxacin was determined by broth dilution method. (MIC), was used to amplify PMQR gene qnrA,qnrB, by PCR. QnrC,qnrD,qnrS,aac (6')-Ib-cr,qepA, and sequencing analysis of PCR positive products were carried out to determine the gene subtypes. Results the resistant and sensitive strains of 256 strains of Pseudomonas aeruginosa to ciprofloxacin were 65 and 180, respectively. MIC50 and MIC90 were 0.5 渭 g / ml, 16 渭 g / ml;, respectively. Only one of the strains detected qnrA gene, and its PCR positive product was confirmed to be qnrA1 subtype. the MIC of ciprofloxacin to the strain was 2 渭 g / ml;. No qnrB,qnrC,qnrD,qnrS,aac (6')-Ib-cr and qepA genes were detected. Conclusion qnrA1 gene was found in Pseudomonas aeruginosa for the first time in China, which mediates the low level resistance of bacteria to ciprofloxacin. PMQR has not yet become one of the main mechanisms of quinolone resistance of Pseudomonas aeruginosa.
【作者单位】：中山大学附属第三医院急诊科;
【分类号】：R378.991

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