Inhibition of adhesion of Clostridium difficile to human intestinal cells after treatment with serum and intestinal fluid isolated from mice immunized with nontoxigenic C. difficile membrane fraction

•Nontoxigenic Clostridium difficile membrane fraction (ntCDMF) generated an immune response.•Serum and intestinal fluid of immunized mice hindered adhesion of parental strain.•Serum and intestinal fluid also inhibited the adhesion of toxigenic strains.•The ntCDMF has potential as a preventive measure against C. difficile infection.

Diarrhea and pseudomembrane colitis caused by Clostridium difficile infection is a global health concern because of the high recurrence rate after standard antibiotic therapy. Vaccination presents a powerful countermeasure against disease recurrence. In this study, mice vaccinated with the nontoxigenic C. difficile membrane fraction generated a marked immune response to the antigen, as demonstrated by the serum IgG and intestinal fluid IgA levels. Significantly, pretreatment with harvested IgG- and IgA-containing fluids was sufficient to prevent in vitro adhesion of C. difficile to human Caco-2 intestinal cells. These results highlight the potential of nontoxigenic C. difficile membrane fraction as a vaccine candidate for C. difficile infection.