Figure 4.

Vaccination with S. Typhi porins reduces the bacterial burden following challenge. C57BL/6J mice were injected intradermally in the ear with vehicle (Veh), proteinase K-digested porins (PorK), porins (PorID), or intraperitoneally with porins (PorIP) or heat-inactivated S. Typhi (HIS) at day 0 with a homologous boost at day 14 (A). At day 28, IgM (B) and IgG (C) serum titers were measured, and mice were challenged intraperitoneally with 10⁵ S. Typhi CFU. At day 29, bacterial burden in the spleen (D) and liver (E) was determined (n = 7; 3 independent experiments; significant difference for a Kruskal–Wallis test ** p < 0.05 with Dunn’s multiple comparison).