Antibody responses in mice. A Serum IgG responses to SaoA. B Vaginal IgA responses to SaoA and C Serum IgG to Salmonella Choleraesuis OMPs were measured by ELISA. The data represent reciprocal antibody titers in sera from ten mice orally immunized with attenuated Salmonella carrying either pS-SaoA or pYA3493 (empty vector) and BSG at indicated weeks after immunization. Serum and vaginal wash obtained from individual mice were serially diluted to obtain titers, starting from either 1:50 or 1:10. Error bars represent variation between mice. Significant differences were indicated. **P < 0.01, for Salmonella Choleraesuis with pS-SaoA compared to Salmonella Choleraesuis with pYA3493 in A and C; #
P < 0.05; ##
P < 0.01, for Salmonella carrying either pS-SaoA or pYA3493 compared each other. No antibody responses were detected to antigen tested in mice immunized with the only BSG or in pre-immune sera from vaccinated mice. ELISA was performed twice with identical results.