Fig. 9

In vivo efficacy of ES24 in an S. pneumoniae zebrafish embryo infection model. (A) Viability of S. pneumoniae D39 after overnight incubation with a concentrations series of ES24 or NFT measured with resazurin. (B) Survival of 2 days postfertilization zebrafish embryos infected with S. pneumoniae D39. Embryos were injected with 150 CFU of bacteria in the caudal vein and subsequently treated with 5 μM ES24 or 5 μM NFT by adding the compounds directly to the water 1 h post infection (hpi). ES24 treatment improved the survival rate significantly in zebrafish embryos infected with S. pneumoniae D39 compared with NFT-treated embryos (p < 0.0001) or nontreated infected embryos (p < 0.0001). NFT also improved the survival rate compared with nontreated infected embryos, albeit not significantly (p = 0.4139). Data represents the mean ± SEM. Experiments were performed in biological triplicates with 10 fish per condition in each replicate. Survival rates were compared using log-rank statistics.