Figure 1

Bacterial loads in the brain and BBB permeability in ducks post R. anatipestifer infection. A The bacterial load in the brain tissues of ducks infected with Yb2, Yb2ΔsspA, and cYb2ΔsspA was measured 24 and 48 h post-infection. The data are presented as the means ± standard deviations of ten animals from triplicate experiments. Statistical significance was assessed using two-tailed Student’s t test. The asterisks indicate the level of statistical significance (**, p < 0.01; ****, p < 0.0001). B Three ducks each from Groups 1–4 were injected intravenously with 2% Evans blue solution (0.15 mL) and sacrificed 2 h post-injection. Representative images are shown in the figure. Blue staining in the brain indicates that the BBB was destroyed during infection. C The amounts of Evans blue dye in the brains of ducklings infected with different strains. The data are presented as the means ± standard deviations of three animals from triplicate experiments. Statistical significance was assessed using one-way analysis of variance (ANOVA). The asterisks indicate the level of statistical significance (*, p < 0.05). ns: not significant.