Prediction of the disease-causing potential of the various E.coli strains not yet possible, revealed researchers.
Escherichia coli (E. coli) is a germ that occurs naturally in the gut of mammals and birds, as well as in the human intestinal flora. However, certain E. coli types can cause severe diarrhea in humans. These virulent E. coli types include Shiga toxin-producing E. coli (STEC), also known as Verotoxin-producing E. coli (VTEC). Their damaging effect is due to the fact that STEC produce toxins known as Shiga toxins (Stx), which can cause disease in the human gut. As the best known STEC representative, an enterohaemorrhagic E. coli (EHEC) strain of the serotype O104:H4 was responsible for numerous severe cases of haemolyticuremic syndrome (HUS) and bloody diarrhoea in Germany in 2011, as a result of which 53 people died.
According to evaluations made by the BfR, STEC are most often found in meat, meat products, raw milk and raw milk products from ruminants such as cattle, sheep and goats, but they can also occur in products made from wild ruminants and wild boar, as well as plantbased foods. Although STEC strains can be better classified today using modern molecular methods, a definite prediction of the potential of STEC strains to cause disease in humans is not possible. For this reason, all Shiga toxin-producing E. coli strains are classified as potentially virulent.