<i>S.</i> Typhimurium challenge experiment: an assessment of vaccination efficacy.

<p>Vaccinated C57BL/6 mice groups (PBS: n = 4, MT12: n = 4 and MT13: n = 4) were ampicillin-treated (25 mg by gavage), challenged with wild-type SB300 (amp^r, sm^r) and euthanized at day 3 post-challenge (p.c.) i.e. day 34 post-vaccination. <b>A:</b> Colonization at various host sites after SB300 challenge. <b>B:</b> Enumeration of cecal pathology in terms of 13 point pathoscore scale was determined as described above (see material and methods). Broken lines in the graphs shows minimum detection limit. n.s.: not significant, *: statistically significant (P<0.05, t-test). <b>C:</b> Representative HE-stained cecum sections obtained from SB300-challenged mice groups immunized with PBS, MT12, MT13. Bar, 200 µm. S, submucosal edema; Lp, lamina propria; L, lumen.