Fig. 6.

Mouse IgG and IgA responses after C. difficile infection. Mouse serum and fecal samples (n = 10, M1 to M10) were collected 30 days after an initial spore challenge. Serum IgG titers (A), fecal IgA titers (B), and serum neutralizing titers (C) were measured. Gray and open bars show anti-TcdA and anti-TcdB levels, respectively. Immunization of glucosyltransferase-deficient holotoxins A (aTcdA) and B (aTcdB) induced higher levels of IgG. “Immunized” represents sera from mice immunized with aTcdA and aTcdB. “Infected” represents sera from mice infected with C. difficile.