Assessment of serum IgG antibody responses post-immunization. Titers of serum IgG, IgG1, and IgG2a against a Salmonella-specific antigen OMP in immunized mice were measured by ELISA assay. Mice were subcutaneously injected with lysed JOL1950 while non-stimulated mice were inoculated with 100 μL of sterile PBS. Data are shown as mean ± standard error (SE). NS; non-stimulated, *P < 0.05, (vs. NS).