Fig. 3.

(A) Infection rate in bone marrow-derived macrophages under Sb^V challenge. BMMs were infected with stationary growth phase L. infantum transfected either with vector pcosTL or with pcos-210. After removal of free parasites, the infected macrophages were incubated in the absence or presence of 160 μg ml⁻¹ Pentostam®. After 72 h, the cells were fixed with ice–cold methanol, stained with DAPI, and subjected to fluorescence microscopy. For each dataset, 100 macrophages were examined for the presence of parasites. Experiments were performed in quadruplicate and on separate days. The median infection rates are indicated by horizontal bars. Significance (*p = 0.029) was tested using the Mann–Whitney ranking test. n = 4. (B) Basic expression rate of ARM58 in two clinical isolates of L. braziliensis, PER002 (Sb^III sensitive) and PER104 (Sb^III resistant), measured by qPCR. Experiments were done in duplicate, arbitrary units. (C) ARM58 RNA expression in L. braziliensis populations under various selective pressure. Clone PER002cl7[pcos-210] was subjected to in vitro passage for 4 weeks with twice-weekly medium changes. The populations were kept without selection (2), under 50 μg ml⁻¹ G418 (3), under 3 μM Sb^III (4), or under 10 μM Sb^III (5). The PER002cl7 wild type was used for normalisation (1). Cultures were grown in duplicate, qPCR was done in duplicate for each culture (n = 4). The bars indicate the medians. Asterisks indicate significance (^∗p ⩽ 0.05).