Analysis of colonization and cecal pathology of the vaccinated mice after wild-type S . Typhimurium challenge. Mice immunized with PBS, MT5 and MT4 (n = 5) were treated with ampicillin (25 mg by gavage), challenged with wild-type SB300 (ampr, smr) and sacrificed three days later (day 3 p.c.). Disease parameters like colonization at various host-tissues (A) and cecal pathology (B) were determined. n.s., not significant; *, statistically significant (p < 0.05).