Dr Gill Douce - Characterisation of genes expressed by Clostridium difficile during infection
Clostridium difficile is a bacterium that particularly affects elderly and hospitalised patients, causing chronic and relapsing diarrhoea, which can kill.
Infection occurs when bacteria that normally live in the gut and help to protect us against this organism are killed by antibiotics often given to treat other unrelated infections. The removal of our ‘friendly’ bacteria leaves the gut vulnerable to colonisation by C. difficile. Once the bacteria get established, they grow and release two powerful toxins that are responsible for damaging the gut and causing diarrhoea.
However, we now know that some C. difficile which are unable to make these toxins can also make people ill (called toxin negative strains), so there must be other things the bacterium does in the gut that are responsible for some features of this disease.
The research carried out in my lab focuses on two main aspects of the infection. Firstly, we would like to identify factors such as adhesions that are important in the infection process (do the bacteria need to stick to the gut to make toxins, which bit of the gut do they stick to?). This can be achieved by making genetic mutants (take the bacteria and modify them so they are no longer able to make the specific protein we think is important) and determine whether this affects the way the bacteria are able to cause disease. Secondly, we are interested in developing better ways of preventing this horrible disease by making good vaccines.

These need to activate the immune system so that they can prevent the symptoms when the person comes into contact with the natural infection within the hospital.