FIG 1

(A and B) The whiB4::Tn mutant is attenuated in zebrafish. (A) Adult zebrafish (n = 20) were infected with the indicated strains at 10⁴ CFU bacteria per fish and were monitored for mortalities over an 18-week period. The survival curves were plotted using the Kaplan-Meier method and differences between curves were analyzed using the log-rank test. **, P < 0.01; ****, P < 0.0001. (B) In parallel experiment, zebrafish (n = 20) were infected with the same strains at 10⁴ CFU bacteria per fish, and at indicated time points (2, 6, and 12 weeks) postinfection, 3 live fish per group were sacrificed and bacterial burdens were determined. Data are plotted as mean ± standard error of the mean (SEM). Unpaired Student’s t test: *, P < 0.05; **, P < 0.01. (C and D) whiB4::Tn in infected zebrafish is more tolerant to antibiotic killing than WT. In a separate experiment, zebrafish were infected with the indicated strains at a dose of 10⁴ CFU/fish. At 2 weeks postinfection, animals (n = 5) were treated with ethambutol (1 mM), rifampicin (0.4 mM), or moxifloxacin (0.3 mM) for 1 or 2 weeks, and they were then sacrificed and bacterial burdens were determined. Data are plotted as mean ± standard deviation (SD). Unpaired Student’s t test: *, P < 0.05; **, P < 0.01. COM, the complemented strain.