EHEC - Enterohemorrhagic Escherichia coliEnterohemorrhage E．Coli，EHEC（E.coli O157:H7） EHEC is a type of enterotoxigenic Escherichia coli that causes intestinal bleeding. It produces toxins similar to those produced by Shigella dysenteriae type I.
EHECMainly invading the colon, it can cause necrosis of intestinal mucosal cells in the intestine, leading to tissue lesions and the formation of intestinal wall ulcers; EHEC Escherichia coli O157: H7 is the most virulent strain, with varying levels of resistance to many antibiotics. In severe cases, it can cause symptoms of hemolytic uremic syndrome, and if left untreated, it can lead to death.
EHECCausing invasive lesions in the intestine, mainly in the colon area. Research suggests that the Shiga like toxins produced by ETEC bind to receptors on the microvascular endothelial cells of intestinal wall tissue, causing vascular damage and triggering an increase in local cytokines TNF, LPS, and IL1 β. These cytokines enhance the sensitivity of receptors to toxins, promoting further aggravation of vascular damage. Further research is needed to determine whether this toxin acts on endothelial cells of other organs, triggers the production of cytokines, and causes local damage leading to vascular bleeding.
According to research, animals that can transmit this pathogen include cattle, chickens, sheep, dogs, pigs, etc. There have also been reports of O157:H7 Escherichia coli isolated from the feces of geese, horses, deer, and pigeons. Among them, the carrier rate of cattle is the highest, reaching up to 16%. Can continuously expel bacteria for 1 year.