Figure 6.

Characterization of the in vitro and in vivo expression of the putative effectors (A) and their fitness contribution in E. piscicida during infection of turbot fish (B). (A) qRT-PCR analysis of the expression of the putative effectors during bacterial growth in DMEM, J774A.1 or in vivo in turbot fish at 3 or 7 DPI. The preparation of total mRNA from E. piscicida WT and ΔesrB cells grown in the above-mentioned conditions is detailed in Materials and Methods. *P < 0.05, **P < 0.01 based on Student's t-test. (B) Barcoded WT and in-frame deletion mutants of the putative effectors were recovered from turbot fish inoculated with a pool of WT and mutant strains, and competitive indices (CI) were calculated based on the ratios of individual mutant/WT tags in output vs. input. Data from liver, spleen and kidney at 3 and 7 DPI are shown as the mean ± SEM. *P < 0.05, **P < 0.01 based on ANOVA followed by Dunnett's test for multiple comparisons comparing the data with the corresponding WT (barcode A,B)/WT(barcode C,D). All the experiments were conducted in triplicate with liver, spleen, and kidney samples that were pooled (n = 5) at each time point.