Verotoxins

Verotoxins are a group of potent cytotoxins produced by certain strains of bacteria, most notably Escherichia coli (E. coli). These toxins are also known as Shiga-like toxins due to their structural and functional similarities to the Shiga toxin produced by Shigella dysenteriae. There are two main types, Verotoxin-1 (VT1) and Verotoxin-2 (VT2), with further subtypes existing.

Verotoxins function by inhibiting protein synthesis within host cells. They bind to a specific receptor on the cell surface, a globotriaosylceramide molecule, and are then internalized. Once inside, the toxin cleaves ribosomal RNA, effectively halting the production of essential proteins. This cellular damage can lead to a variety of symptoms, depending on the route of infection and the specific verotoxin involved.

The most well-known association of verotoxins is with enterohemorrhagic E. coli (EHEC) infections. EHEC strains carrying genes for verotoxin production can cause severe gastrointestinal illness, characterized by bloody diarrhea and abdominal cramps. A significant complication of EHEC infection, particularly in young children and the elderly, is hemolytic uremic syndrome (HUS). HUS is a life-threatening condition involving kidney failure, anemia, and low platelet count, directly attributed to the widespread damage caused by verotoxins to the blood vessels in the kidneys. Public health efforts focus on preventing EHEC contamination of food and water sources to reduce the incidence of verotoxin-related illnesses.