Cephamycins inhibit pathogen sporulation and effectively treat recurrent Clostridioides difficile infection

Spore-forming bacteria encompass a diverse range of genera and species, including important human and animal pathogens, and food contaminants. Clostridioides difficile is one such bacterium and is a global health threat because it is the leading cause of antibiotic-associated diarrhoea in hospitals. A crucial mediator of C. difficile disease initiation, dissemination and re-infection is the formation of spores that are resistant to current therapeutics, which do not target sporulation. Here, we show that cephamycin antibiotics inhibit C. difficile sporulation by targeting spore-specific penicillin-binding proteins. Using a mouse disease model, we show that combined treatment with the current standard-of-care antibiotic, vancomycin, and a cephamycin prevents disease recurrence. Cephamycins were found to have broad applicability as an anti-sporulation strategy, as they inhibited sporulation in other spore-forming pathogens, including the food contaminant Bacillus cereus. This study could directly and immediately affect treatment of C. difficile infection and advance drug development to control other important spore-forming bacteria that are problematic in the food industry (B. cereus), are potential bioterrorism agents (Bacillus anthracis) and cause other animal and human infections.