三种方法检测超广谱β-内酰胺酶的结果评价

Evaluation of the results from detection of extended－spectrum β－lactamases by three methods．

目的 评价VITEK－AMS专用药敏卡检测大肠埃希菌和肺炎克雷伯菌超广谱β－内酰胺酶（ESBLs）的可靠性。同时比较纸片扩散筛选法、双纸片协同法检测ESBLs的临床应用价值。方法 以纸片扩散确证法为标准，用VITEK－AMS、纸片扩散筛选法、双纸片协同法检测大肠埃希菌和肺炎克雷伯菌产ESBLs情况。结果 仪器检测为阳性的73株大肠埃希菌和24株肺炎克雷伯菌，用纸片扩散确证法、纸片协同法、纸片扩散筛选法检测也均为阳性。仪器检测为阴性的131株大肠埃希菌和46株肺炎克雷伯菌，用三种方法分别检出一定数量的阳性株。结论 仪器检测ESBLs 易造成假阴性，纸片扩散筛选法会造成假阳性。而双纸片协同法由于同时用四种底物检测，其敏感性、特异性均较理想，适合临床应用。

 Objective To evaluate the reliability and value of clinical application of VITEK－AMS disc diffusion scteen test and double－disk synergy test for the detection of extended－spectrum β－lactamasesESBLs produced by E．coil and K．pneumoniae． Methods With disc diffusion confirmatory test as standard ESBLs produced by E．coil and K．pneumioniae was detected by VITEK－AMS disc diffusion screen test and double－disk synergy test． Results All the 73 strains of E．coli and 24 strains of K．pneumoniase which were found to be ESBLs positive when detected by VITEK GNS－506 showed ESBLs positive． when detected with disc diffusion confirmatory testdouble－disk synetgy test and disc diffusion screen test． But a certain number of strains among 131 of E．coli and 46 of K．pneumoniase showing ESBLs negative in VITEK GNS－506 were found positive when detected with other three tests． Conclusion Detection of ESBLs using VITEK－AMS may obtain false positive and by disc diffusion screen test false nenative results Detecting ESBLs by double－disk synergy test with four indicators shows ideal sensitivity and specificity and is suitable for routine clinical application． 