Gastrointestinal infection due to enterohaemorrhagic Escherichia coli O157:H7 is the chief cause of a severe form of blood poisoning known as haemolytic uraemic syndrome in children.
A recent study has shown that this syndrome is much more common in children who have been given antibiotics to deal with the E. coli infection. Doctors are not certain how the antibiotics trigger the syndrome.
However, researchers believe that antibiotics, taken at any stage during E. coli infection, induce the gene for the Shiga toxin characteristic of the disease (N Engl J Med, 2000; 342: 1930-6).