Institute for Food Safety and Hygiene, Vetsuisse Faculty University of Zurich, CH-8057 Zurich, Switzerland.
J Food Prot. 2013 May;76(5):871-3. doi: 10.4315/0362-028X.JFP-12-365.
Following the recent outbreak of Shiga toxin-producing Escherichia coli (STEC) O104:H4 infection in Germany, the demand for fast detection of STEC has again increased. Various real-time PCR-based methods enabling detection of Shiga toxin genes (stx) have been developed and can be used for applications in food microbiology. The present study was conducted to evaluate the reliability of seven commercially available real-time PCR systems for detection of stx1 and stx2 subtypes. For this purpose, pure cultures of 18 STEC strains harboring all known stx1 and/or stx2 subtypes were tested. Only one of the seven real-time PCR systems detected all known stx1 and stx2 subtypes. Six systems failed to detect the stx2f subtype. One system missed stx2 subtypes reported in association with severe human disease. Because the presence of certain stx genes (subtypes) is considered an important indicator of STEC virulence, systems differentiating between the stx1 and stx2 gene groups provide added value. Reliable and fast detection of stx genes is of major importance for both diagnostic laboratories and the food industry.
近期德国发生了产志贺毒素大肠杆菌（STEC）O104:H4 感染疫情，对 STEC 的快速检测需求再次增加。已经开发出各种基于实时 PCR 的方法来检测志贺毒素基因（stx），可用于食品微生物学领域。本研究旨在评估七种市售实时 PCR 系统检测 stx1 和 stx2 亚型的可靠性。为此，对携带所有已知 stx1 和/或 stx2 亚型的 18 株 STEC 纯培养物进行了测试。只有一种实时 PCR 系统能够检测到所有已知的 stx1 和 stx2 亚型。六种系统未能检测到 stx2f 亚型。有一种系统未能检测到与严重人类疾病相关的 stx2 亚型。由于某些 stx 基因（亚型）的存在被认为是 STEC 毒力的重要指标，因此区分 stx1 和 stx2 基因群的系统具有附加价值。stx 基因的可靠和快速检测对诊断实验室和食品行业都非常重要。
