resulting in the development of disease symptoms, including diarrhea and pseudomembranous colitis. Recent reports have
described the role of C. difficile cell surface adhesins in intestinal colonization [10e13], and have led us to the notion that targeting these factors with antibodies could impede C. difficile colonization and thus function as an effective countermeasure against CDI. Purified C. difficile adhesins including surface-layer protein have demonstrated to be effective as partially protective antigens in experimental animals [14e16]; however, purification of proteins for this purpose can be time-consuming and expensive. In the present study, we demonstrate the potential of vaccination with
the nontoxigenic C. difficile membrane fraction (ntCDMF) as an inexpensive alternative to purified adhesins. Furthermore, the potential advantage of membrane fractions is related to the possibility to target a larger repertoire of membrane proteins. In brief, we harvested serum and intestinal fluid samples from mice vaccinated with the prepared ntCDMF and examined their effects on the adhesion of C. difficile cells to human Caco-2 intestinal cells.