Figure 2

Macrophage infection assays. Percentages of internalization (A) and intracellular survival at 48 h (B) in J774A.1 macrophages of the wild type R. equi 103S⁺ strain, the virulence plasmid cured R. equi 103S⁻ strain, R. equi Δetrx3, and R. equi Δetrx3 + pSET-etrx3 (Δetrx3 + etrx3). Bacterial viability was calculated by quantifying the number of colony forming units (CFUs) of each strain and by normalizing these data against R. equi 103S⁺ CFUs. Data are expressed as mean ± SD of three technical replicates repeated in three independent experiments. One-way ANOVA and post hoc Tukey’s multiple comparison tests were performed to assess for statistical significance in relation to the wild type strain. **p-value < 0.01.