Comparison of Shiga Toxin-Producing Escherichia coli Detection Methods Using Clinical Stool Samples
Comparison of Shiga Toxin-Producing Escherichia coli Detection Methods Using Clinical Stool Samples
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DOI：
10.2353/jmoldx.2010.090221
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发表时间：
2010-07-01
影响因子：
4.1
通讯作者：
Gilmour, Matthew W.
中科院分区：
文献类型：
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作者：
Chui, Linda;Couturier, Marc R.;Gilmour, Matthew W.
能够识别粪便标本中志贺毒素特异性遗传决定因素的分子诊断工具允许采用公正的方法检测临床样本中产生志贺毒素的大肠杆菌（STEC），并可以指示何时需要基于培养的分离方法。人们越来越认识到临床相关的 STEC 不限于单一的 O157 血清型，因此针对毒素编码决定簇的诊断测定必须能够解释血清型之间存在的任何遗传变异。在这项研究中，使用传统 PCR 和四种针对 stx1 和 stx2 志贺毒素编码序列的实时 PCR 检测（HybProbe、TaqMan、SYBR Green 和 LUX）来鉴定富集粪便样本 (n = 36) 以及一组 O157 和非 O157 菌株 (n = 64) 中的 STEC。针对 stx1 和 stx2 的 PCR 检测对于富集的粪便样本具有不同的特异性和敏感性值。使用来自纯培养物的 DNA 进行的分子测定表明，某些引物并非对所有 stx2 变体都敏感。该评估得出的结论是，考虑到成本、周转时间和检测性能，基于 TaqMan 的探针最适合高通量临床诊断实验室。 (J Mol Diagn 2010, 12:469-475; DOI: 10.2353/jmoldx.2010.090221)
Molecular diagnostic tools capable of identifying Shiga toxin-specific genetic determinants in stool specimens permit an unbiased approach to detect Shiga toxin-producing Escherichia colt (STEC) in clinical samples and can indicate when culture-based isolation methods are required. It is increasingly recognized that clinically relevant STEC are not limited to the singular O157 serotypes, and therefore diagnostic assays targeting toxin-encoding determinants must be able to account for any genetic variation that exists between serotypes. In this study conventional PCR and four real-time PCR assays (HybProbe, TaqMan, SYBR Green, and LUX) targeting the stx1 and stx2 Shiga toxin coding sequences were used to identify STEC in enriched stool samples (n = 36) and a panel of O157 and non-O157 strains (n = 64). PCR assays targeting stx1 and stx2 had variable specificity and sensitivity values with enriched stool samples. Molecular assays using DNA from pure cultures revealed that some primers were not sensitive to all stx2 variants. This evaluation concluded that the TaqMan-based probes were most appropriate in high throughput clinical diagnostic laboratories in consideration of cost, turn around time, and assay performance. (J Mol Diagn 2010, 12:469-475; DOI: 10.2353/jmoldx.2010.090221)