Anti-sporulation strategies for Clostridium difficile infections

Clostridium difficile is the most significant cause of hospital-acquired diarrhoea worldwide. Unlike most pathogens, C. difficile produces spores. Spores are produced in large numbers in the host and are highly persistent. They contaminate hospital environments and play a critical role in the infection process, facilitating efficient disease transmission. Despite the critical importance that spores play in infection, our understanding of their biology lags far behind that of other well-studied organisms. Furthermore, strategies to prevent spore production from C. difficile would be invaluable for infection control purposes, however, none are available. Our recent work has unexpectedly shown that some members of the cephamycin family of beta-lactam antibiotics inhibit C. difficile spore formation. This research proposal is centred around this novel observation.
Our hypotheses are that:
1. Cephamycins inhibit sporulation in C. difficile and will reduce spore shedding, disease transmission and recurrence in an animal infection model.
2. Cephamycins act by inactivating sporulation-specific C. difficile penicillin binding proteins.
3. The cephamycin structure can be modified to construct a compound(s) with stronger binding affinity to anti-sporulation targets.
The specific aims are:
1. To evaluate cephamycin efficacy in reducing spore shedding, transmission and recurrence using an animal infection model.
2. To identify and genetically analyse sporulation-specific cephamycin binding targets.
3. To characterise the kinetics and binding of cephamycins to spore-specific PBPs.
4. To construct cephamycin derivatives with stronger binding affinity and greater in vivo anti-sporulation efficacy.
The outcome of this research will be instructive in our understanding of the C. difficile sporulation process and will provide proof-of principle data to support the unique approach of using sporulation inhibitors to reduce contamination, transmission and recurrence.