Casanova Natalia A, Redondo Leandro M, Dailoff Gabriela C, Arenas David, Fernández Miyakawa Mariano E
Instituto de Patobiología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria, Buenos Aires, Argentina.
Instituto de Patobiología, Centro de Investigación en Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.
Toxicon. 2018 Jun 15;148:149-154. doi: 10.1016/j.toxicon.2018.04.019. Epub 2018 Apr 24.
Shiga toxin-producing Escherichia coli (STEC) have been implicated as the cause of enterotoxemias, such as hemolytic uremic syndrome in humans and edema disease (ED) of pigs. Stx1 and Stx2 are the most common types found in association with illness, but only Stx2e is associated with disease in the animal host. Porcine edema disease is a serious affection which can lead to dead causing great losses of weaned piglets. Stx2e is the most frequent Stx variant found in porcine feces and is considered the key virulence factor involved in the pathogenesis of porcine edema disease. Stx2e binds with higher affinity to Gb4 receptor than to Gb3 which could be due to amino acid changes in B subunit. Moreover, this subtype also binds to Forssman glycosphingolipids conferring upon Stx2e a unique promiscuous recognition feature. Manifestations of edema disease are caused by systemic effects of Stx2e with no significant morphologic changes in enterocytes. Endothelial cell necrosis in the brain is an early event in the pathogenesis of ED caused by Stx2e-producing STEC strains. Further studies are needed to generate techniques and tools which allow to understand the circulation and ecology of STEC strains in pigs even in resistant animals for diagnostic and epidemiological purposes.
产志贺毒素大肠杆菌（STEC）被认为是肠毒素血症的病因，如人类的溶血尿毒综合征和猪的水肿病（ED）。Stx1和Stx2是与疾病相关的最常见类型，但只有Stx2e与动物宿主中的疾病有关。猪水肿病是一种严重的疾病，可导致断奶仔猪死亡，造成巨大损失。Stx2e是猪粪便中最常见的Stx变体，被认为是参与猪水肿病发病机制的关键毒力因子。与Gb3相比，Stx2e与Gb4受体的结合亲和力更高，这可能是由于B亚基中的氨基酸变化。此外，该亚型还与福斯曼糖鞘脂结合，赋予Stx2e独特的混杂识别特征。水肿病的表现是由Stx2e的全身作用引起的，肠细胞没有明显的形态学变化。脑内皮细胞坏死是由产Stx2e的STEC菌株引起的水肿病发病机制中的早期事件。需要进一步研究以开发技术和工具，以便了解猪体内STEC菌株的循环和生态学，即使在抗性动物中也是如此，用于诊断和流行病学目的。
