目的 了解连云港地区临床分离的大肠埃希菌质粒介导喹诺酮类抗菌药物耐药基因的携带状况,为临床喹诺酮类药物耐药的预防提供指导.方法 采用PCR检测88株分离自连云港地区的大肠埃希菌株的质粒介导喹诺酮耐药基因qnrA,qnrB,qnrS和aac(6')-Ib-cr,将阳性结果进行测序分析确认,并通过将aac(6')-Ib序列与Genbank登记序列比对以确定aac(6')-Ib-cr;分析基因阳性菌株的喹诺酮类药物的药敏结果.结果 在检测的大肠埃希菌临床分离株中,共检出qnr基因阳性7株(7.95%),其中qnrB基因2株(2.27%),qnrS基因5株(5.68%),未检出qnrA基因阳性菌株.检出aac(6')-Ib基因阳性菌株12株(13.64%),经测序确定其中6株(6.82%)为aac(6')-Ib-cr基因.检测出的12株qnr和aac(6')-Ib-cr基因阳性的大肠埃希菌中,8株对喹诺酮类耐药,3株对喹诺酮类敏感,1株对左旋氧氟沙星敏感但对环丙氟派酸耐药;有11株为产超广谱β-内酰胺酶(ESBLs)菌株.结论 连云港地区临床分离的大肠埃希菌中存在qnr和aac(6')-Ib-cr基因阳性菌株的流行,喹诺酮类敏感菌株与耐药菌株中均有qnr基因和aac(6')-Ib-cr基因的存在.qnr和aac(6')-Ib-cr基因往往和ESBLs同时存在,应加强临床分离菌株的质粒介导喹诺酮类抗菌药物耐药基因监测,以防止其传播与流行.%Objective To investigate the appearance of plasmid-mediated quinolone resistance genes in Enterobacter coli from Lianyungang location for clinical treatment. Methods Detection of plasmid-mediated resistance gene qnrA, qnrB, qnrS and aac (6')-Ib-cr of 88 clinical isolated Escherichia coli strains were performed by PCR. Gene-positive PCR products were se-quenced to confirm positive results,and by the aac (6')-Ib sequence alignment with Genbank registration to determine the aac (6')-Ib-cr. Analysis drug susceptibilty results of positive strains. Results In 88 clinical strains of E. Coli detected ,7 strains were detected in qnr-positive (7. 95%), including qnrB positive 2(2. 27%),qnrS positive 5(5. 68%), not detected qnrA positive strains. Detection aac (6')-Ib positive isolates 12 (13. 64%) ,of which 6 strains (6. 82%) were aac (6')-Ib-cr. Detected in 12 qnr and aac(6')-Ib-cr gene positive E. Coli, 8 strains of quinolone resistance, 3 strains sensitive to quinolones, one strain was levofloxacin sensitive but resistant tociprofloxacin,11 were ESBLs producting strains. Conclusion Evidences suggested the emergence of plasmid-mediated quinolone resistance gene-borne species in clinical isolated E. Coli in Linayungang location,and it often coexist with ESBLs,the monitoring and control should be strengthened in order to prevent the transmission and spreading of these strains.
展开▼
