<i>S</i>. <i>flexneri</i> induces neutrophil death in Sept15 morphants.

<p>A-B. Quantification of neutrophils in <i>lyz</i>:dsRed larvae injected with (A) Ctrl or (B) Sept15 morpholino (Mo), uninfected (open circles) or infected for 6 h with a low (closed circles) or high (grey circles) dose of <i>S</i>. <i>flexneri</i> M90T, from 4 or more larvae per treatment from 3 independent experiments. Circles represent individual larvae. Mean ± SEM also shown (horizontal bars). Significance testing performed by ANOVA with Bonferroni posttest. **, P<0.01; ***, P<0.001. C. Representative images of <i>lyz</i>:dsRed larvae injected with Ctrl, Sept15, or Sept15 + Irf8 Mo. Scale bar, 250 μm. D. Quantification of neutrophils in <i>lyz</i>:dsRed larvae injected with Ctrl (open circles), Sept15 (closed circles), or Sept15 + Irf8 (grey circles) Mo. Circles represent individual larvae. Mean ± SEM also shown (horizontal bars). Significance testing performed by ANOVA with Bonferroni posttest. ***, P<0.001. E. Survival curves of Sept15 or Sept15 + Irf8 morphants infected with <i>S</i>. <i>flexneri</i> M90T (low dose). Pooled data from 3 independent experiments per treatment using at least 15 larvae per treatment. Significance testing performed by Log Rank test. F. Enumeration of bacteria at 0, 24, or 48 hpi from Sept15 (open circles) or Sept15 + Irf8 (closed circles) morphants infected with <i>S</i>. <i>flexneri</i> M90T (low dose). Half-filled circles represent enumerations from larvae at time 0 and are representative of inocula for both conditions. Pooled data from 3 independent experiments per inoculum class using up to 3 larvae per treatment. Circles represent individual larvae, and only larvae having survived the infection (thus far) included here (i.e., dead larvae not homogenised for counts). Mean ± SEM also shown (horizontal bars). Significance testing performed by Student’s t test.