Département de Microbiologie et Immunologie, CHU Sainte-Justine, Université de Montréal, Montréal, Québec, Canada.
J Clin Microbiol. 2013 Feb;51(2):481-6. doi: 10.1128/JCM.02219-12. Epub 2012 Nov 21.
Shiga toxin-producing Escherichia coli (STEC) is a well-known cause of sporadic and epidemic food-borne gastroenteritis. A low infectious dose, approximately 10 microorganisms, is sufficient to cause disease that may lead to hemolytic-uremic syndrome. The objective of this study was to compare the performances of an in-house real-time PCR, a commercial enzyme immunoassay (EIA) (Premier EHEC; Meridian Bioscience), and culture on sorbitol MacConkey agar for the detection of STEC in a tertiary care pediatric hospital. Of 632 stool samples tested, 21 were positive for STEC. All were detected by PCR, 6 were detected by EIA, and only 5 O157 STEC isolates were identified by culture. Among the 15 specimens falsely negative by EIA, there were 9 Stx1, 2 Stx2, and 4 Stx1 and Stx2 STEC isolates. The latter group included 2 O157 STEC isolates that would have been missed if only EIA had been performed. To our knowledge, this is the first prospective study performed in a pediatric hospital which demonstrates the superiority of PCR over EIA for the detection of STEC. We conclude that PCR is specific and more sensitive than EIA. PCR should be considered for routine use in clinical settings where molecular detection facilities are available. Its lower limit of detection, equivalent to the infectious dose, is an obvious advantage for patient care and public health surveillance.
产志贺毒素大肠杆菌（STEC）是一种众所周知的散发性和流行性食源性肠胃炎的病因。感染剂量低，约 10 个微生物，足以引起可能导致溶血性尿毒综合征的疾病。本研究的目的是比较内部实时 PCR、商业酶联免疫吸附试验（EIA）（Premier EHEC；Meridian Bioscience）和在山梨醇麦康凯琼脂上培养对三级儿科医院中 STEC 的检测性能。在检测的 632 份粪便样本中，有 21 份 STEC 呈阳性。所有这些都是通过 PCR 检测到的，6 种是通过 EIA 检测到的，只有 5 种 O157 STEC 分离株通过培养鉴定。在 15 份 EIA 假阴性标本中，有 9 株为 Stx1，2 株为 Stx2，4 株为 Stx1 和 Stx2 STEC 分离株。后者包括 2 株 O157 STEC 分离株，如果仅进行 EIA，这些分离株将被遗漏。据我们所知，这是首次在儿科医院进行的前瞻性研究，证明了 PCR 检测 STEC 的优势优于 EIA。我们得出结论，PCR 比 EIA 更具特异性和敏感性。在有分子检测设施的临床环境中，应考虑将 PCR 常规用于临床。其检测下限与感染剂量相当，这对患者护理和公共卫生监测具有明显优势。
