Fig 1. Lesion progression in mice infected with L. amazonensis or L. guyanensis and in vitro infection of macrophages.

Groups of 5 BALB/c (open circles) or C57BL/6 (filled circles) mice were infected in one of the hind footpads with 1x10⁶ stationary phase promastigotes of L. amazonensis (A) or L. guyanensis (B). Lesion progression was assessed weekly for up to 20 weeks by measuring the hind footpads. Lesion size was expressed as the difference between infected and non-infected footpad. Each point represents mean ± SE obtained from 5 mice. Macrophages were infected with L. amazonensis (C, E, G) or L. guyanensis (D, F, H) at a 10:1 parasite:macrophage ratio and incubated for up to 4 days. Infected cells were counted and results are expressed as percentage of infected macrophages (C, D), number of parasite/cell (E, F) and infection index (G, H). Infection index was estimated as the mean percentage of infected cells x the mean number of parasites per infected cells. Bars represent mean ± SE of two to six (depending on the time point) independent experiments. Statistically significant differences between the two groups at a P < 0.05 are represented by (*). Statistically significant differences between values of the same group as compared to values at 24h at a P < 0.05 are represented by (#).