Antimonial susceptibility and in vivo behaviour of Leishmania major isolates collected in Algeria before and after treatment.

The repercussions of cutaneous leishmaniasis therapy on the behaviour and drug susceptibility of Leishmania major parasites is poorly documented. This study explored the link between antimonial susceptibility and in vivo behaviour in Leishmania major isolates collected before and after treatment in Algeria. This study was performed on 3 isolates collected from patients prior to treatment and paired with 3 isolates collected from the same patient after treatment failure. Their in vitro susceptibility towards trivalent (SbIII) and pentavalent (SbV) antimony were ascertained, and their in vivo behaviour was evaluated by determining their capacity to disseminate, proliferate and induce lesions in mice. No relationship was observed between in vitro antimony resistance and parasite fitness in the murine model.