Fig. 1

Activity of TB47 (T) against M. ulcerans. a Time-killing curves of TB47 against AlMu in liquid culture. Concentrations (μg mL⁻¹). Data are expressed as mean ± SD from three independent biological repeats. The experiment was performed in triplicate (three independent experiments) and the representative results are shown. b–d Mice were treated from 12 days post infection of AlMu (ALI = 1.09 ± 0.28). Data are expressed as mean ± SD of five samples. b RLUs detected from left hind footpads of the same batch of live mice treated for 5 days and stopped for 3 days. Statistical analysis was performed using unpaired Student’s t-test. c RLUs and CFUs of footpad tissue suspension at day 0 and day 7. The experiments for b, c were performed in triplicate (three independent experiments) and the representative results are shown. The correlation coefficients (R²) of RLU and CFU for the in vivo experiments were 0.966 (including the positive) and 0.898 (TB47 treated groups only), respectively. Correlation analysis was performed using Pearson’s correlation test. The linearity of the relationship of RLU and CFU for the footpad suspension is valid when the CFUs are from 2.5 to 6.2 log₁₀ CFU mL⁻¹. Statistical analysis was performed using unpaired Student’s t-test, *P < 0.001; **P < 0.0001. d Footpad RLUs detected after completion of treatment for monitoring relapse. e Kinetic curves of RLUs from the footpads of live mice treated with different regimens. Data are expressed as mean ± SD of five samples. f Time to footpad swelling after completion of antibiotic treatment. Time to footpad swelling in mice treated with either rifampin + streptomycin for 5 weeks (gray circles) or 6 weeks (black triangles), or TB47 for 1 week (red square) or for 2 weeks (purple triangle). Statistical differences were determined by Log-rank (Mantel-Cox) test with 15 mice in each group. T, TB47; BL, base line; Ui, uninfected (for RLU detection, Ui is the base line); Ut, untreated; R, rifampin, 25; S, streptomycin, 150; Dosage (mg kg⁻¹). The dotted green lines indicated the base line (the limit of detection). Data are expressed as mean ± SD. ^*P < 0.001; ^**P < 0.0001