235株血流感染大肠埃希菌耐药性分析

Antimicrobial resistance of 235 strains of Escherichia coli isolated from patients with bloodstream infection

摘要:

目的分析某院血流感染患者标本分离的大肠埃希菌耐药性，为临床合理应用抗菌药物提供依据。方法采用BacT/Alert全自动血培养仪、VITEK 2细菌鉴定仪对患者血标本进行培养、鉴定；KB药敏纸片测定法进行药敏试验并筛选出产超广谱β内酰胺酶（ESBLs）细菌。结果2009—2011年共分离血流感染大肠埃希菌235株，ESBLs阳性90株，阳性率38.30%。产ESBLs菌株对氨苄西林、头孢噻肟、头孢曲松100%耐药；对亚胺培南/西司他丁、美罗培南敏感率均为100%，对头孢美唑、阿米卡星敏感率＞90%。非产ESBLs菌株耐药率最高的是氨苄西林，达70.63%；对亚胺培南/西司他丁、美罗培南敏感率均为100%，对阿米卡星、头孢噻肟、头孢美唑敏感率＞95%。产ESBLs菌株的耐药率均明显高于非产ESBLs菌株。在含有β内酰胺酶抑制剂的复合抗菌药物中，只有头孢哌酮/舒巴坦对产ESBLs大肠埃希菌的敏感率＞90%，哌拉西林/他唑巴坦和替卡西林/克拉维酸的敏感率均未超过80%。结论血流感染大肠埃希菌产ESBLs株的耐药性较高，临床用药应根据患者感染菌的耐药情况制定合理的个体化治疗措施。

Abstract:

ObjectiveTo investigate antimicrobial resistance of Escherichia coli (E.coli) isolated from patients with bloodstream infection, and provide evidence for rational use of antimicrobial agents in clinical practice.MethodsBacT/Alert automated blood culture system and VITEK 2 automated identification system were used for bacterial culture and identification. Antimicrobial susceptibility testing and detection of extendedspectrum βlactamases (ESBLs)producing strains were performed by KirbyBauer method. ResultsFrom 2009 to 2011, a total of 235 strains of E.coli were isolated from patients with bloodstream infection, 90 (38.30%) of which were ESBLs positive strains. The resistant rates of ESBLsproducing strains to ampicillin, cefotaxime and ceftriaxone were all 100%, but susceptibility rate to imipenem/cilastatin and meropenem were all 100%, to cefmetazole and amikacin were >90%. The resistant rate of nonESBLsproducing strains to ampicillin was the highest (70.63%), susceptibility rate to imipenem/cilastatin and meropenem were both 100%, to amikacin, cefotaxime, and cefmetazole were all >95%. The resistant rate of ESBLsproducing strains was significantly higher than that of the nonESBLsproducing strains. Of βlactamase inhibitor, only susceptibility rate of ESBLsproducing E.coli to cefoperazone/sulbactam was>90%,  susceptibility rates to piperacillin / tazobactam and ticarcillin/clavulanate were both<80%. ConclusionAntimicrobial resistant rate of ESBLsproducing strains causing bloodstream infection is high, individualized treatment strategies should be made according to antimicrobial resistance of bacteria causing infection in patients.