Role of FliC and FliD flagellar proteins of Clostridium difficile in adherence and gut colonization

In vitro and in vivo adhesive properties of flagella and recombinant flagel lin FliC and flagellar cap FliD proteins of Clostridium difficile were anal yzed. FliC, FliD, and crude flagella adhered in vitro to axenic mouse cecal mucus. Radiolabeled cultured cells bound to a high degree to FliD and weak ly to flagella deposited on a membrane. The tissue association in the mouse cecum of a nonflagellated strain was 10-fold lower than that of a flagella ted strain belonging to the same serogroup, confirming the role of flagella in adherence.