Figure 7

Increased virulence and pathogenesis of Δtle in a zebrafish embryo model of infection.A, schematic overview of in vivo experiments. B, survival of infected embryos with the R strain (275 ± 27 CFU), the S strain (280 ± 36 CFU), Δtle (264 ± 33 CFU), and Δtle::C (281 ± 47 CFU). The graph shows the result of four pooled independent experiments. Embryos were marked dead in the absence of a heartbeat. Statistical analysis was performed using Log-rank (Mantel-Cox) test. ∗∗∗∗: p < 0.0001; ∗∗: p < 0.01, ns: non-significant. C, bacterial burden from infected embryos at 2, 3, and 5 dpi. The graph shows the result of three pooled independent experiments. n = 5 embryos per time-point per condition. CFU counts were Log₁₀ transformed. ∗: p < 0.05, ∗∗: p < 0.01, ∗∗∗: p < 0.001, and ∗∗∗∗: p < 0.0001. D, imaging of infected embryos at 3 dpi. One zoomed representative image of the head is shown per condition. Scale bars represent 0.2 mm. CFU, colony-forming units.