VITEK-AMS仪检测超广谱-β内酰胺酶的结果评价

Evaluation of Detecting Extended-spectrum-β-lactamases by VITEK-AMS

目的 评价 VITEK全自动微生物分析仪 (VITEK- AMS)检测大肠埃希菌和肺炎克雷伯菌产超广谱 β-内酰胺酶 (ESBL)的可靠性及选择最佳筛选底物。方法 同时使用纸片筛选和确证实验与 VITEK32型 - AMS仪对临床分离的 195株大肠埃希菌和 5 2株肺炎克雷伯菌进行 ESBL 检测。结果 确证实验中 ,大肠埃希菌和肺炎克雷伯菌产 ESBL阳性率分别为 2 3.6 % ,19.8% ,VITEK- AMS仪和纸片确证实验同时检测为阳性的为 5 1株 ,同时检测为阴性的为 192株 ,有四株确证实验阳性而 VITEK- AMS仪漏检 ,VITEK- AMS仪检测 ESBL的特异性为 10 0 % ,灵敏度为 92 .7%。初筛实验中 ,头孢噻肟筛选的灵敏度为 10 0 % ,是我院的最佳筛选底物 ,其次为头孢曲松、头孢泊肟、氨曲南 ,单用头孢他啶漏检率最高。结论 VITEK- AMS是检测 ESBL的较好方法。头孢噻肟是我院的最佳筛选底物。

Objective To evaluate the reliability of VITEK AMS for detection of extended spectrum β lactamases (ESBL) in Escherichia coli and Klebsiella pneumoniae, and to find the best ESBL screening substrates.Method VITEK AMS and disc diffusion screening and confirmatory test were used to detect ESBL in 195 strains of Escherichia coli and 52 strains of Klebsiella pneumoniae clinical isolates simultaneously.Results 46(23.6%)strains of Escherichia coli and 9(19.8%) strains of Klebsiella pneumoniae producing ESBL were detected by disc diffusion confirmatory test. 51 were positive and 192 negative by both VITEK AMS and confirmatory tests. 4 strains producing ESBL were positive by confirmatory test, while negative by VITEK AMS . The sensitivity and specificity of VITEK AMS were 92.7% and 100%, respectively. In screening test, the sensitivity of Cefotaxime was 100%,and it was the best substrate of screening ESBL, followed by ceftriaxone, cefpodoxime, aztreonam. Ceftazidime was the worst.Conclusions It′s a good method to detect ESBL with VITEK AMS .Cefotaxime was the best substrate to screen and detect ESBL.