Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA.
Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA.
Foodborne Pathog Dis. 2020 Dec;17(12):782-791. doi: 10.1089/fpd.2020.2814. Epub 2020 Aug 21.
Shiga toxin-producing (STEC) are major foodborne pathogens and seven serogroups, O26, O45, O103, O111, O121, O145, and O157, that account for the majority of the STEC-associated illness in humans. Similar to cattle, swine also harbor STEC and shed them in the feces and can be a source of human STEC infections. Information on the prevalence of STEC in swine feces is limited. Therefore, our objective was to utilize polymerase chain reaction (PCR) assays to determine prevalence of major virulence genes and serogroups of STEC. Fecal samples ( = 598), collected from finisher pigs within 3 weeks before marketing in 10 pig flows located in 8 states, were included in the study. Samples enriched in broth were subjected to a real-time PCR assay targeting three virulence genes, Shiga toxin 1 (1), Shiga toxin 2 (2), and intimin (), which encode for Shiga toxins 1 and 2, and intimin, respectively. A novel PCR assay was designed and validated to detect serogroups, O8, O20, O59, O86, O91, O100, O120, and O174, previously reported to be commonly present in swine feces. In addition, enriched fecal samples positive for Shiga toxin genes were subjected to a multiplex PCR assay targeting O26, O45, O103, O104, O111, O121, O145, and O157 serogroups implicated in human clinical infections. Of the 598 fecal samples tested by real-time PCR, 25.9%, 65.1%, and 67% were positive for 1, 2, and , respectively. The novel eight-plex PCR assay indicated the predominant prevalence of O8 (88.6%), O86 (35.5%), O174 (24.1%), O100 (20.2%), and O91 (15.6%) serogroups. Among the seven serogroups relevant to human infections, three serogroups, O121 (17.6%), O157 (14%), and O26 (11%) were predominant. PCR-based detection indicated high prevalence of Shiga toxin genes and serogroups that are known to carry Shiga toxin genes, including serogroups commonly prevalent in cattle feces and implicated in human infections and in edema disease in swine.
产志贺毒素（STEC）是主要的食源性病原体，有七个血清群，包括 O26、O45、O103、O111、O121、O145 和 O157，这些血清群导致了人类大多数与 STEC 相关的疾病。与牛类似，猪也携带 STEC 并在粪便中排出，因此可能成为人类 STEC 感染的来源。有关猪粪便中 STEC 流行情况的信息有限。因此，我们的目标是利用聚合酶链反应（PCR）检测来确定 STEC 的主要毒力基因和血清群的流行情况。从位于 8 个州的 10 个猪群中即将上市前 3 周内的育肥猪收集了 598 份粪便样本。对在肉汤中富集的样本进行实时 PCR 检测，检测三个毒力基因，志贺毒素 1（1）、志贺毒素 2（2）和内膜蛋白（），分别编码志贺毒素 1 和 2 以及内膜蛋白。设计并验证了一种新的 PCR 检测方法，用于检测先前报道在猪粪便中常见的血清群 O8、O20、O59、O86、O91、O100、O120 和 O174。此外，对志贺毒素基因检测呈阳性的富集粪便样本进行了多重 PCR 检测，检测与人类临床感染相关的 O26、O45、O103、O104、O111、O121、O145 和 O157 血清群。在通过实时 PCR 检测的 598 份粪便样本中，分别有 25.9%、65.1%和 67%对 1、2 和 呈阳性。新的八重 PCR 检测表明，O8（88.6%）、O86（35.5%）、O174（24.1%）、O100（20.2%）和 O91（15.6%）血清群的流行率较高。在与人类感染相关的七个血清群中，三个血清群 O121（17.6%）、O157（14%）和 O26（11%）占主导地位。基于 PCR 的检测表明，已知携带志贺毒素基因的志贺毒素基因和血清群的流行率很高，包括在牛粪便中普遍存在并与人类感染和猪水肿病有关的血清群。
