FIG. 1.
Lymphocytes are protective against infection with a low-virulence strain but not with a highly virulent strain of M. ulcerans. Wild-type (▪), Rag2−/− (□), or nude (□) mice were subcutaneously infected in the footpads with 3 × 105 AFB of M. ulcerans 5114 (A and C) or 98-912 (B and D). At different time points, the infected footpads were collected and homogenized for bacterial load determination by AFB counting. The data points represent the means ± the standard errors of the mean (SEM) (n = 5). The results of one experiment representative of two are shown. The statistical significance was calculated using the Student t test, comparing wild-type and immunodeficient mice (***, P < 0.001).