FIG. 3.
FimA-specific serum IgG (A) and IgA (B) titers following coimmunization with recombinant S. gordonii. Rats were orally inoculated with the live recombinant S. gordoni vaccine strains (SgFimN and SgFimC2) or the control GP251 strain at weeks 0 and 3. Each inoculation consisted of two doses (48 h apart) of 109 CFU of live cells instilled into the oral cavity. Serum and saliva were collected at weeks 3, 6, and 9, and FimA-specific antibody titers in serum were determined by PCFIA. Serum antibody titers (relative fluorescence units [RFU]) are expressed as the mean ± the standard error (n = 6). ∗∗∗, P < 0.001 versus control-immunized group.