Figure 2.

Prophylactic administration of SCIgA/M preparation limits St entry and reduces symptoms. (A) Bacterial counts measured in Peyer's patches (PPs), mesenteric lymph nodes (MLNs), spleen, and liver 6 days post-infection by oral administration of 2 × 10⁷ St into mice prophylactically treated with Ab preparations. (B) Weight loss and disease score (see section Materials and Methods) determined at day 6 post-infection as a function of the Ab preparation administered prophylactically. Each panel compiles the results of three independent experiments, conducted with 3 mice per group. (C) Histologic examination (hematoxylin and eosin staining) of intestinal tissue sections obtained from infected mice 6 days post-administration with a single dose of either 2 × 10⁷ St alone, or in the presence of prophylactically applied Ab preparation. Typical patterns for “No Ab”/IgG (left) and IgA/M/SCIgA/M (right) representative of more than 10 sections. L, Lumen; V, Villus. Magnification, x 20 for all images. ns, non-significant; *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001.