Lesion progression and bacterial proliferation of <i>M. ulcerans</i> in the footpads of mice treated or non-treated with RS.

<p>Mice were infected with <i>M. ulcerans</i> strain 98–912 and were left untreated (closed circles) or subjected to treatment with RS for 10 weeks (open circles). (A) Lesion progression was assessed by measurement of footpad swelling (n = 15). Bacterial proliferation was assessed by CFU (B) and AFB counts (C) (n = 5). (D) Percentage of well stained (black bars) versus poorly stained (including beaded) (grey bars) AFB in the footpad for the antibiotic treated group of mice. At day 12 post-infection, treatment was initiated until day 82. (E) AFB at day 12 post-infection, with well stained (arrowheads) and beaded (arrow) bacilli. (F) AFB at day 156 post-infection, with beaded (arrow) and poorly stained (triangle) bacilli. Asterisks represent significant differences between treated and non-treated mice on panels B and C (**, <i>P</i><0.01, ***, <i>P</i><0.001). Significant differences over time for the well stained or poorly stained group in panel D were determined by comparing each time point with the following (***, <i>P</i><0.001). Grey bar on panels A, B and C represents the time period of antibiotic administration. d.l., detection limit; n.d., not detected. †, mice were sacrificed for ethical reasons after the emergence of ulceration. Results are from one representative experiment of two independent experiments. Data points and bars represent the mean ± SEM.