Merz C S, Kramer C, Forman M, Gluck L, Mills K, Senft K, Steiman I, Wallace N, Charache P
Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287-7093.
J Clin Microbiol. 1994 May;32(5):1142-7. doi: 10.1128/jcm.32.5.1142-1147.1994.
Rapid (2.5- to 3.5-h) enzyme immunoassays (EIAs) for the detection of Clostridium difficile toxins have been developed. We report the results of simultaneous testing of 700 fresh stool specimens by the tissue culture cytotoxin assay and four EIAs (Bartels Prima System C. difficile Toxin A EIA, Cambridge Biotech Cytoclone A+B EIA, Meridian Diagnostics Premier C. difficile Toxin A EIA, and TechLab C. difficile Tox-A Test EIA). In cases of disagreement, culturing for toxigenic C. difficile was performed. A total of 61 (8.7%) specimens from 46 patients were positive for C. difficile toxin. The sensitivity of the cytotoxin assay was 87%, and that of culture was 93%. In comparison with the cytotoxin assay results, the sensitivity and specificity of the EIAs were as follows: Bartels, 87 and 96%; Cambridge, 89 and 99%; Meridian, 87 and 98%; and TechLab, 87 and 95%, respectively. In comparison with the cytotoxin assay plus toxigenic culture results, the sensitivity and specificity of the EIAs were as follows: Bartels, 84 and 97%; Cambridge, 85 and 99%; Meridian, 79 and 98%; and TechLab, 80 and 96%, respectively. The EIAs varied in positive predictive values (PPVs). A high PPV was seen with the Cambridge EIA (96%); lower PPVs were seen with the TechLab (64%), Bartels (72%), and Meridian (80%) EIAs because of high false-positive rates. The negative predictive values (98 to 99%) were excellent with all EIAs. Results were indeterminant with 0.3% of the samples by the Meridian EIA and 3% by all the other EIAs. Although the EIAs were less sensitive than the cytotoxin assay, they provide same-day results and may be useful in laboratories without tissue culture facilities.
已开发出用于检测艰难梭菌毒素的快速（2.5至3.5小时）酶免疫测定法（EIA）。我们报告了通过组织培养细胞毒素测定法和四种EIA（巴特尔斯拉姆系统艰难梭菌毒素A EIA、剑桥生物技术公司细胞克隆A + B EIA、子午线诊断公司高级艰难梭菌毒素A EIA和TechLab艰难梭菌毒素A检测EIA）对700份新鲜粪便标本进行同步检测的结果。在结果不一致的情况下，对产毒艰难梭菌进行培养。共有来自46名患者的61份（8.7%）标本艰难梭菌毒素呈阳性。细胞毒素测定法的灵敏度为87%，培养法的灵敏度为93%。与细胞毒素测定法的结果相比，各EIA的灵敏度和特异性如下：巴特尔斯拉姆，87%和96%；剑桥，89%和99%；子午线，87%和98%；TechLab，分别为87%和95%。与细胞毒素测定法加产毒培养结果相比，各EIA的灵敏度和特异性如下：巴特尔斯拉姆，84%和97%；剑桥，85%和99%；子午线，79%和98%；TechLab，分别为80%和96%。各EIA的阳性预测值（PPV）有所不同。剑桥EIA的PPV较高（96%）；TechLab（64%）、巴特尔斯拉姆（72%）和子午线（80%）EIA的PPV较低，因为假阳性率较高。所有EIA的阴性预测值（98%至99%）都很好。子午线EIA对0.3%的样本结果不确定，其他所有EIA对3%的样本结果不确定。虽然EIA的灵敏度低于细胞毒素测定法，但它们能提供当日结果，可能对没有组织培养设施的实验室有用。
