FIGURE 7.

Animal systemic infection experiments. (A) Determination of bacterial virulence. Seven-day-old ducks were inoculated intra-tracheally with the APCE94, APCE94ΔeivC, or APCE94CΔeivC strains at 10⁸ colony-forming units (CFUs). Ducks injected with PBS were used as negative controls. Survival was monitored until 7 days post-infection. (B) Bacterial colonization and proliferation in ducks. Groups of eight 7-day-old ducks were intra-tracheally infected with 10⁸ CFUs of bacteria. Bacteria were recovered from the lung, blood, liver and spleen at 24 h post-infection. A non-parametric Mann–Whitney U-test was conducted to determine statistical significance (^∗p < 0.05).