Research led by Dr Stephanie Schüller, is to look at how strains of toxin-producing E. coli bacteria infect our bodies and cause life-threatening conditions. A better understanding of the biology of these strains will help to develop new ways of preventing the devastating effects these foodborne pathogens can have.

Shiga toxin-producing E. coli bacteria (STEC) are a leading cause of foodborne illness worldwide, and a particularly virulent strain was behind the outbreak that affected Germany and France in 2011. As well as causing severe bloody diarrhoea and abdominal cramps, some people develop a complication known as haemolytic uraemic syndrome (HUS). Particularly affecting the elderly and children under 5, HUS can lead to kidney damage and renal failure and in 5-15% of cases it leads to death.  There is no specific treatment for HUS, apart from dialysis and blood transfusion.

Dr Stephanie Schüller

To help in the development of more effective treatment strategies against STEC and HUS, Dr Stephanie Schüller, Lecturer in Infection and Immunity  at the Norwich Medical School at UEA and visiting scientist at IFR, has received a £380,000 New Investigator Research Grant from the Medical Research Council to understand more precisely how STEC triggers these devastating conditions. The research will be carried out at IFR in collaboration with Dr Sacha Lucchini.

After eating contaminated food, STEC attaches itself to the lining of the gut and starts to produce a toxin, called Shiga toxin, which crosses the gut lining and enters the bloodstream causing HUS. How this happens is not known, in part because of a lack of a good model system. Developing a system is difficult because the gut is a low oxygen environment, but human intestinal cells grown in the laboratory need oxygen to keep them alive. Dr Schüller and colleagues have recently overcome this to produce a low oxygen human gut cell culture system, and with this they can now probe how STEC behaves in the human gut. It is particularly important to examine STEC in this environment, as previous research has shown that low oxygen levels trigger STEC to colonise the gut lining.

The new research will work out how the toxin crosses the lining of the gut, and look at how the low oxygen levels activate the bacteria. Getting a better understanding of what happens in the early stages of infection by this dangerous bacterial pathogen will give us a better chance of developing treatments or even vaccines to counter its effects.