Multicenter evaluation of the Clostridium difficile TOX A/B TEST
Multicenter evaluation of the Clostridium difficile TOX A/B TEST
复制标题
DOI：
10.1128/jcm.36.1.184-190.1998
复制
发表时间：
1998-01-01
影响因子：
9.4
通讯作者：
Schwalbe, R
中科院分区：
文献类型：
--
作者：
Lyerly, DM;Neville, LM;Schwalbe, R
艰难梭菌是美国和许多其他工业化国家医院内腹泻的主要原因，被认为是一个主要的健康问题，因为它能够引起严重的肠道疾病，导致并发症，如复发和感染，由于万古霉素耐药肠球菌。该疾病由该病原体产生的两种毒素A和B引起。在这项研究中，我们评估了TOX A/B试验，这是一种新的检测毒素A和B的l-h酶免疫测定法（EIA）。我们将该试验与组织培养试验进行了比较，后者被认为是C.艰难测试在TechLab，Inc.进行内部评价。（弗吉尼亚州布莱克斯堡）以及四个临床实验室的非现场检测。在检测的1，152份样本中，165份经TOX A/B检测和组织培养呈阳性，973份经两种检测均呈阴性。其敏感性和特异性分别为92.2%和100%。阳性和阴性预测值分别为100和98.6%，TOX A/B TEST与组织培养的相关性为98.8%。当不一致的样本通过培养解决时，敏感性和特异性分别为93.2%和98.9%，阳性和阴性预测值分别为100%和98.8%，相关性为99.0%。没有标本经TOX A/B试验呈阳性，经组织培养呈阴性。14份标本经TOX A/B试验呈阴性，但经组织培养呈阳性。其中，2例经致突变培养呈阴性，5例经致突变培养呈阳性，7例无法进行进一步检测。没有不确定结果，因为该试验没有不确定区域。在一项单独的研究中，对102份组织培养和TOX A/B试验呈阳性的标本进行了毒素A特异性EIA检查。鉴定了2份标本，推测含有毒素A阴性、毒素B阳性（toxA-/toxB+）分离株。一份标本来自具有与C一致的临床病史的患者。艰难感染通过在固体培养基和肉汤中选择性培养从这些标本中获得的分离株在脑心浸液透析瓶中生长时检测toxA-/toxB+，这两种毒素均刺激体外产生。我们的研究结果表明，TOX A/B试验适合作为艰难梭菌病的辅助诊断方法，因为它与组织培养相关性良好，并可通过毒素A特异性EIA检测可能遗漏的分离株。
Clostridium difficile, the primary cause of nosocomial diarrhea in the United States and many other industrialized countries, is recognized as a major health concern because of its ability to cause severe intestinal disease leading to complications such as relapses and infections due to vancomycin-resistant enterococci. The disease results from two toxins, toxins A and B, produced by this pathogen. In this study, we evaluated the TOX A/B TEST, a new l-h enzyme immunoassay (EIA) that detects toxins A and B. We compared the test with the tissue culture assay, which is recognized as the "gold standard" for C. difficile testing. Evaluations were per formed in-house at TechLab, Inc. (Blacksburg, Va.) and off-site at four clinical laboratories. Of 1,152 specimens tested, 165 were positive by the TOX A/B TEST and tissue culture and 973 were negative by both tests. The sensitivity and specificity were 92.2 and 100%, respectively. The positive and negative predictive values were 100 and 98.6%, respectively, and the correlation of the TOX A/B TEST with tissue culture was 98.8%. When discrepant samples were resolved by culture, the sensitivity and specificity were 93.2 and 98.9%, respectively, The positive and negative predictive values were 100 and 98.8%, respectively, with a correlation of 99.0%. There were no specimens that were positive by the TOX A/B TEST and negative by tissue culture. Fourteen specimens were negative by the TOX A/B TEST but positive by tissue culture. Of these, two were negative by toxigenic culture, five were positive by toxigenic culture, and seven were not available for further testing. There were no indeterminate results, since the test does not have an indeterminant zone. In a separate study, 102 specimens that were positive by tissue culture and the TOX A/B TEST were examined in toxin A-specific EIAs. Two specimens that presumptively contained toxin A-negative, toxin B-positive (toxA-/toxB+) isolates were identified. One specimen was from a patient with a clinical history consistent with C. difficile infection. Isolates obtained from these specimens by selective culture on solid media and in broth tested toxA-/toxB+ when grown in brain heart infusion dialysis flasks, which stimulate in vitro production of both toxins. Our findings show that the TOX A/B TEST is suitable as a diagnostic aid for Ci difficile disease because it correlates well with tissue culture and detects isolates that may be missed,vith toxin A-specific EIAs.