FIG 3.

(A) Expression and purification of protein FliCD. The gene sequence encoding FliCD was synthesized and cloned in Bacillus megatarium. FliCD was purified from bacterial lysate via Ni-affinity chromatography and analyzed via SDS-PAGE. (B–E) FliCD immunizations via the intraperitoneal (i.p.) route induce anti-FliCD antibody responses. Groups of C57BL/6 mice (n = 10) were immunized 4 times at 12-day intervals with 10 or 20 μg of FliCD with alum as an adjuvant. Sera and feces were collected, and anti-FliCD IgG/IgA titers were measured via standard ELISA. The data are presented as the mean ± SEM (*, P < 0.05; **, P < 0.01; ns, not significant).