Non-optimal translational fidelity in Salmonella impairs zebrafish infection. (A) Pairs of WT/WT, WT/rpsD* and WT/rpsL*cells (grown to early-stationary phase in LB at 37°C) were mixed at equal numbers and delivered to zebrafish via paramecia. The colony forming units were determined 24 and 48 h post-infection. Empty symbols indicate that no Salmonella cells were recovered from the fish and thus no ratio was calculated. 10 fish were used for each pair of Salmonella strains at each time point. (B) WT, rpsD* and rpsL* cells carrying mCherry (red fluorescence) were delivered to the gut of zebrafish via food-borne infection. Zebrafish are Tg(mpo::egfp)ⁱ¹¹⁴ (neutrophils are green fluorescent). The blue line indicates the gut area. 4 fish were used for each Salmonella strain. (C) Quantitation of the number of neutrophils recruited to the gut by WT, rpsD* and rpsL* cells. Each dot in A and C represents one fish. The average Salmonella CFU recovered from each fish at 24 and 48 h post infection is 4 × 10³ and 3 × 10⁴, respectively. **P < 0.01; ***P < 0.001 determined using one-way ANOVA. Error bars represent one standard deviation.