Figure 6.

Limitation of Salmonella enterica Typhimurium strain SL1344 (St) dissemination in the presence of antibody preparations after oral administration. Mice were orally administered 2 × 10⁷ St alone or in association with preparations IgA and IgM (IgA/M), secretory-like IgA and IgM (SCIgA/M), or IgG. (A) Bacterial counts in mucosal tissues [Peyer’s patches (PPs), mesenteric lymph nodes] were determined by plating of tissue lysates 48 h post-delivery of St or immune complexes prepared in the presence of 1 mg antibodies. (B) Similar experiment as in (A), using immune complexes made of 2 × 10⁷ St and decreasing amounts of antibodies, with bacterial counts assessed in PPs, mesenteric lymph nodes and the spleen at day 6 post-administration. Experiments were performed twice, with three mice per group, and the compilation of the two experimental sets is depicted. Bars represent medians. Statistical analyses were performed by comparison with the “No Ab” experimental group. Ab, antibody; MLNs, mesenteric lymph nodes; CFUs, colony forming units.