Host responses to Clostridium difficile infection

Clostridium difficile is a disease-causing bacterium associated with antibiotic use in hospitals. Disease severity varies from mild to severe diarrhoea, to life threating illnesses, which result from the activity of two toxins, TcdA and TcdB. However, these toxins do not contribute to disease equally. This thesis examined how TcdA and TcdB induce an immune response during infection, how they contribute to disease outside of the gastrointestinal tract and how they alter gastrointestinal function. These studies increased our understanding of C. difficile disease and showed that therapeutic approaches should focus on TcdB as this toxin is the main mediator of disease.