Figure 1.

Exposure to paraoxon improves resistance to oral but not to systemic infection with virulent bacteria. Mice treated with paraoxon or saline for 3 weeks were infected with virulent Salmonella either (A) orally [1 × 10⁴ colony-forming units (CFUs)/mouse] or (B) i.p. (5 × 10³ CFUs/mouse) and followed for survival. Graphs represent the mean values ± SEM of pooled data from 2 to 3 independent experiments (n = 15–17/group). Asterisks denote statistically significant differences between the control and experimental groups (**p < 0.01). Log-rank (Mantel–Cox) statistical test was used for the analysis.