临床分离阴沟肠杆菌中qnr基因及其耐药性检测

目的了解临床分离阴沟肠杆菌中qnr基因的分布以及对喹诺酮类等抗菌药物的耐药性。方法琼脂稀释法测定29株阴沟肠杆菌对5种氟喹诺酮类抗菌药物以及头孢美唑、亚胺培南、氯霉素、庆大霉素、四环素的耐药性;PCR检测qnr基因并将阳性扩增产物进行测序分析。结果阴沟肠杆菌对诺氟沙星、氧氟沙星、左氧氟沙星、环丙沙星、加替沙星的耐药率高达79.3%~89.7%;对头孢美唑、氯霉素、庆大霉素、四环素、亚胺培南的耐药率分别为96.6%、89.7%、82.8%、55.2%、13.8%;29株阴沟肠杆菌中,2株细菌携带qnrA1基因,占6.9%。结论阴沟肠杆菌对氟喹诺酮类等多种抗菌药物耐药显著、为多药耐药菌,少数菌株中存在qnr基因,临床应加强检测和监测。

Detection of qnr Genes in Enterobacter cloacae Isolates and Their Resistance

OBJECTIVE To investigate the prevalence of qnr genes in Enterobacter cloacae isolates and their resistance.METHODS Susceptibility of E.cloacae isolates to fluoroquinolones and other antimicrobial agents was tested by agar dilution and qnr genes were identified by PCR and sequencing.RESULTS The resistant rate to norfloxacin,ofloxacin,levofloxacin,and ciprofloxacin was from 79.3% to 89.7% and that to cefmetazole,chloramphenicol,gentamicin,tetracycline,and imipenem was 96.6%,89.7%,82.8%,55.2%,and 13.8%,respectively.The qnrA1 gene was identified in two isolates.CONCLUSIONS E.cloacae isolates are highly resistant to most of antimicrobial agents and a few isolates carry qnr genes,so more attention should be paid to survey and detect those strains.