STX2 and hemolytic-uremic syndrome: Shiga toxin-producing Escherichia coli (STEC) are associated with human illness and are defined by the presence of the phage-encoded Shiga toxin genes, stx1 and/or stx2. Symptoms of STEC infection range from mild gastroenteritis through to severe bloody diarrhoea and approximately 6% of cases develop haemolytic uraemic syndrome (HUS);[1] HUS is a serious condition where shiga toxins affect the blood and kidneys.