Infection of zebrafish embryos with the <i>P</i>. <i>aeruginosa mgtC</i> mutant.

<p>(A) Diagram of 30 hours post-fertilization (hpf) zebrafish embryo showing the injection site used in this study (arrow). All injections were done in the caudal vein (CV) just behind to the urogenital opening (UGO). Y: Yolk, CHT: Caudal Hematopoietic Tissue. Scale bar, 100 μm. (B) Survival curves of embryos infected with PAO1 wild-type stain or PAO1 Δ<i>mgtC</i> mutant and PBS-injected (control). Approximately 1200–1400 CFU <i>P</i>. <i>aeruginosa</i> were microinjected into the caudal vein (n = 20 per group). Results are expressed as the percentage of surviving on each hour post-infection. Representative results of three biologically independent replicates are shown. Embryos are significantly more susceptible to infection with PAO1 wild-type than Δ<i>mgtC</i> mutant (<i>P</i><0.001). (C) 30 hpf embryons are intravenously infected with PAO1 or Δ<i>mgtC</i> mutant expressing mCherry. Representative fluorescence microscopy images of 18 hpi embryos infected with PAO1 (top panel) or PAO1 Δ<i>mgtC</i> mutant (bottow panel) are shown (1200–1400 CFU). Scale bar, 200 μm. (D) 30 hpf zebrafish embryos are intravenously infected with mCherry-expressing PAO1 (left panel) or PAO1 Δ<i>mgtC</i> mutant (right panel) and imaged by confocal microscopy. Arrows indicate maximum intensity projection of macrophages that phagocytose bacteria close to the site of injection at 1 hpi. Scale bar, 10 μm. (E) Survival curves of <i>pu</i>.<i>1</i> morphant (<i>pu</i>.<i>1</i> mo) embryos (n = 20 each) infected with 900 CFU of PAO1 wild type stain or PAO1 Δ<i>mgtC</i> mutant compared to the PBS- injected control. Representative results of three biologically independent replicates are shown. No statistically significant difference is obtained between wild type-infected embryos and Δ<i>mgtC</i> mutant-infected embryos (ns: non significant).