Passive immunisation of hamsters against Clostridium difficile infection using antibodies to surface layer proteins.

Clostridium difficile is a major cause of antibiotic-associated diarrhoea and the primary cause of pseudomembraneous colitis in hospitalised patients. We assessed the protective effect of anti-surface layer protein (SLP) antibodies on C. difficile infection in a lethal hamster challenge model. Post-challenge survival was significantly prolonged in the anti-SLP treated group compared with control groups (P=0.0281 and P=0.0283). The potential mechanism of action of the antiserum was shown to be through enhancement of C. difficile phagocytosis. This report indicates that anti-SLP antibodies can modulate the course of C. difficile infection and may therefore merit closer investigation for use as constituents of multi-component vaccines against C. difficile associated diarrhoea.