引起尿路感染的大肠埃希菌的耐药谱分析

Analysis on drug resistance spectrum of Escherichia coli causing urinary tract infection

目的调查引起患者尿路感染的大肠埃希菌的检出率及其耐药谱,为临床合理应用抗菌药物提供参考。方法收集分离自2014年度本院住院患者的尿培养阳性菌株共488株,采用VITEK2全自动微生物分析仪(法国梅里埃公司)进行菌种鉴定和药敏试验。超广谱β-内酰胺酶(ESBLs)菌的检测则采用美国临床和实验室标准协会(CLSI)推荐的双纸片法确证试验。结果引起尿路感染的488株病原菌中,共检到大肠埃希菌235株(占48.16%,235/488),其中产ESBLs菌株54株(占23.0%,54/235)。亚胺培南、替加环素、阿米卡星、哌拉西林钠/舒巴坦钠、哌拉西林/他唑巴坦对产ESBLs的大肠埃希菌具有较强的抗菌活性;产ESBLs菌株具有多耐药性,对氨苄西林、哌拉西林、头孢唑啉、头孢噻肟、头孢曲松和头孢他啶的耐药率均高于90%,对氨曲南、替卡西林/克拉维酸钾、复方新诺明、环丙沙星、庆大霉素、妥布霉素和左氧氟沙星的耐药率均高于60%,对头孢吡肟、头孢西丁和呋喃妥因的耐药率为分别为53.70%、36.00%和31.48%,其耐药率大多明显高于非产ESBLs菌株(P<0.05)。本次研究发现3株耐亚胺培南的大肠埃希菌。结论引起尿路感染的大肠埃希菌的耐药现象严重,尤其是产ESBLs菌株,临床上需及时监测细菌的耐药性变迁,为临床抗感染药物治疗提供参考依据。

Objective To investigate the detection rate and drug resistance spectrum of Escherichia coli causing urinary tract infection to provide reference for rational use of antibacterial drugs.Methods A total of 488 strains of pathogenic bacteria isolated from urine culture of hospitalized in our hospital during 2014 year were collected.The VITEK2 compact automatic bacterial identification instrument（France Bio-Merieux company）was employed to identify the bacteria and conduct the drug susceptibility test.The double disk diffusion confirmatory method recommended by CLSI（2005）was adopted to detect ESBLs.Results Among 235 strains of pathogenic bacteria causing urinary tract infection,235strains（48.16%,235/488）were Escherichia coli,in which 54 strains were ESBLs-producing strains（23.0%,54/235）.Tigecycline,imipenem,amikacin,piperacillin/sulbactam,piperacillin/tazobactam had strong antibacterial activity against ESBL-producing Escherichia coli;the ESBLs producing strains had multiple drug resistance,the resistance rates to ampicillin,piperacillin,cefazolin,cefotaxime,ceftriaxone and ceftazidime were higher than90%,which to aztreonam,ticarcillin/clavulanic acid,cotrimoxazole,ciprofloxacin,gentamicin,tobramycin and levofloxacin were higher than 60%,which to cefepime,cefoxitin and nitrofurantion were 53.70%,36.00% and 31.48%respectively,and most of them were significantly higher than that of non-ESBL-producing strains（P〈0.05）.The study found that 3strains of Escherichia coli were resistant to imipenem.Conclusion The drug resistance of Escherichia coli causing urinary tract infection is serious,especially the ESBLs producing strains.In clinic,the changes of bacterial drug resistance need timely to be monitored in order to provide reference for clinical anti-infective drug therapy.