Functionally active Shiga toxins may be detected using Vero cell toxicity test. This is why these bacteria are also called verotoxin or verocytotoxin-producing E. coli (VTEC).
VTEC are important food-borne pathogens in humans. With many of the outbreaks of VTEC infections being directly or indirectly associated with food, there have also been extensive economic losses to food processors and suppliers.
Verotoxins are A:B5 toxins, made up of a pentameric receptor-binding B subunit and a single catalytically active A subunit. They belong to a larger family of functionally similar ribosome-inactivating proteins, which also includes the castor bean toxin, ricin.
In patients, VTEC strains are associated with watery or bloody diarrhoea, haemorrhagic colitis, and the haemolytic and uremic syndrome. Hemolytic uremic syndrome (HUS) is a potentially fatal complication after infection with enterohemorrhagic Escherichia coli, such as the infamous serotype O157:H7.
VTEC can be transmitted to humans through direct or indirect contamination of foods by faecal material. Undercooked ground beef and raw milk have often been implicated in foodborne infection.
Verotoxin
