A New Zebrafish Model of Oro-Intestinal Pathogen Colonization Reveals a Key Role for Adhesion in Protection by Probiotic Bacteria
Figure 5
Protective effect of selected strains against gnotobiotic zebrafish larva infection by E. ictaluri.
A. Four dpf-old freshly hatched axenic zebrafish larvae were kept germ-free or incubated with selected protective bacterial strains for 2 days prior to exposure to E. ictaluri at 6 dpf. Mortality was monitored daily after E. ictaluri infection. Control non-infected larvae are shown in gray. Asterisks indicate significant difference from E. ictaluri-infected population (***p<0.001). B. Inflammation marker expression in pretreated E. ictaluri-infected larvae. qRT-PCR was performed on 5 individual larvae per group using primers specific to il1b, tnfa and il10 on RNA extracted at 3 dpi ( = 9 dpf) from germ-free or E. coli MG6155 F′ pre-colonized zebrafish larvae exposed to E. ictaluri at 3 days post infection. Results were normalized to mean expression in germ-free animals; mean ± SEM. Asterisk indicates significant difference between E. ictaluri-infected and uninfected populations (**p<0.01, ***p<0.001).