Escherichia coli carrying prophage with genes that encode for Shiga toxins are categorized as Shiga toxin-producing E. coli (STEC) pathotype. Illnesses caused by STEC in humans, which are often foodborne, range from mild to bloody diarrhea with life-threatening complications of renal failure and hemolytic uremic syndrome and even death, particularly in children. As many as 158 of the total 187 serogroups of E. coli are known to carry Shiga toxin genes, which makes STEC a major pathotype of E. coli. Seven STEC serogroups, called top-7, which include O26, O45, O103, O111, O121, O145, and O157, are responsible for the majority of the STEC-associated human illnesses. The STEC serogroups, other than the top-7, called “non-top-7” have also been associated with human illnesses, more often as sporadic infections. Ruminants, particularly cattle, are principal reservoirs of STEC and harbor the organisms in the hindgut and shed in the feces, which serves as a major source of food and water contaminations. A number of studies have reported on the fecal prevalence of top-7 STEC in cattle feces. However, there is paucity of data on the prevalence of non-top-7 STEC serogroups in cattle feces, generally because of lack of validated detection methods. The objective of our study was to develop and validate 14 sets of multiplex PCR (mPCR) assays targeting serogroup-specific genes to detect 137 non-top-7 STEC serogroups previously reported to be present in cattle feces. Each assay included 7–12 serogroups and primers were designed to amplify the target genes with distinct amplicon sizes for each serogroup that can be readily identified within each assay. The assays were validated with 460 strains of known serogroups. The multiplex PCR assays designed in our study can be readily adapted by most laboratories for rapid identification of strains belonging to the non-top-7 STEC serogroups associated with cattle.

大肠杆菌 携带带有编码志贺毒素的基因的噬菌体被归类为志贺毒素生产 大肠杆菌（STEC）原型。由STEC引起的人类疾病通常为食源性疾病，范围从轻度腹泻到血性腹泻，危及生命的并发症包括肾衰竭和溶血性尿毒症综合征，甚至死亡，尤其是在儿童中。总共187个血清群中有158个大肠杆菌 已知携带志贺毒素基因，这使STEC成为主要的病原体 大肠杆菌。与STEC相关的大多数人类疾病均由七个称为T-7的STEC血清群组成，其中包括O26，O45，O103，O111，O121，O145和O157。除前7名外，STEC血清群还被称为“非前7名”，也与人类疾病有关，更多是作为零星感染。反刍动物，特别是牛，是STEC的主要储藏地，并在后肠和粪便中带有生物，它们是食物和水污染的主要来源。大量研究报告了牛粪中前7位STEC的粪便流行率。但是，由于缺乏经过验证的检测方法，有关牛粪中非前7位STEC血清群的患病率数据很少。我们研究的目的是开发和验证针对血清群特异性基因的14组多重PCR（mPCR）分析，以检测先前据报道存在于牛粪便中的137个非top-7 STEC血清群。每个测定包括7-12个血清群，引物设计用于扩增每个血清群具有不同扩增子大小的靶基因，可以在每个测定中容易地鉴定它们。使用460株已知血清群菌株对测定进行了验证。我们的研究中设计的多重PCR分析方法可以为大多数实验室快速适应，以快速鉴定属于与牛相关的非Top-7 STEC血清群的菌株。每个测定包括7-12个血清群，引物设计用于扩增每个血清群具有不同扩增子大小的靶基因，可以在每个测定中容易地鉴定它们。使用460株已知血清群菌株对测定进行了验证。我们的研究中设计的多重PCR分析方法可以为大多数实验室快速适应，以快速鉴定属于与牛相关的非Top-7 STEC血清群的菌株。每个测定包括7-12个血清群，引物设计用于扩增每个血清群具有不同扩增子大小的靶基因，可以在每个测定中容易地鉴定它们。使用460株已知血清群菌株对测定进行了验证。我们的研究中设计的多重PCR分析方法可以为大多数实验室快速适应，以快速鉴定属于与牛相关的非Top-7 STEC血清群的菌株。