阴沟肠杆菌临床分离株中qnr基因的流行现状及耐药性检测

目的了解阴沟肠杆菌中质粒介导喹诺酮类耐药基因qnrA、qnrB、qnrS的流行现状及耐药性检测。方法 PCR法对57株环丙沙星耐药的阴沟肠杆菌进行qnrA、qnrB、qnrS基因检测,并用琼脂稀释法对11种抗菌药物的耐药性测定。结果 57株阴沟肠杆菌中阴沟肠杆菌对5种喹诺酮类药物的耐药率高达89.5%～100%,对氨苄西林、四环素、头孢曲松、头孢美唑、庆大霉素、亚胺培南的耐药率分别为100%、64.9%、87.7%、93%、49.1%和100%。qnrA基因阳性19株(33.3%),qnrB基因阳性15株(26.3%),qnrS基因阳性2株(3.5%),qnrA基因和qnrB基因同时阳性8株,qnrA基因和qnrS基因同时阳性1株,qnrB基因和qnrS基因同时阳性1株。结论我院阴沟肠杆菌临床分离株中存在qnr基因的流行,qnr阳性菌株呈多重耐药,应加强对该类基因的监测及临床用药监管。

Evaluate of qnr Genes in Enterobacter cloacae isolates and resistance

Objective To evaluate the prevalence and resistance of qnr gene in clinical isolates of Enterobacter cloacae.Methods The qnrA,qnrB and qnrS gene in 57 strains of ciprofloxacin-resistant Enterobacter cloacae isolates were detected by PCR;Susceptibility of Enterobacter cloacae isolates to fluoroquinolones and other antimicrobial agents was tested by agar dilution.Results The resistant rate to 5 fluoroquinolones was from 89.5% to 100% and that to ampicillin,tetracycline,ceftriaxone,cefmetazole,gentamicin and imipenem was 100%,64.9%,87.7%,93%,49.1% and 100%,Among the 57 Enterobacter cloacae strains,there were 19 strains(33.3%) carrying qnrA gene,15 strains(26.3%) carrying qnrB gene,2 strains(3.5%) carrying qnrS gene,8 strains carryign qnrA gene and qnrB gene,only one strain carriying qnrA gene andqnrS gene,1 strains carrying qnrB gene and qnrS gene.Conclusion The qnr gene is prevalent in our hospital,qnr positive strains were multi-drug resistant,so more attention should be paid to survey and detect those strains.