Fig. 5. Protection efficacies of Salmonella-based LI vaccines against S. typhimurium. BALB/c mice (n = 10) vaccinated with either Salmonella-based LI vaccine constructs (the co-mixture of 4 vaccine candidates) or PBS were challenged at 6 weeks post-vaccination with a virulent Salmonella strain. Mortality and bacterial recovery from spleen were recorded. (A) Mortality in vaccinated and PBS control groups. (B) Bacterial load in survived mice post-challenge.

Each data point represents mean ± standard deviation of 5 mice per group. A non-parametric χ² test was used to analyze significant differences in mortality, and Student's t-test for bacterial load.

LI, Lawsonia intracellularis; PBS, phosphate buffered saline; LfliC, Lawsonia flagellin; Lhly, Lawsonia hemolysin.

^*p < 0.05.