Metacyclogenesis ofLeishmania (Viannia) guyanensis: a comprehensive study of the main transformation features in axenic culture and purification of metacyclic promastigotes by negative selection withBauhinia purpurealectin

Leishmania (Viannia) guyanensisis one species that causes cutaneous leishmaniasis in the New World. The incidence of infections with this parasite is probably underestimated and few studies exist on this species, despite its epidemiological importance. In particular, there are no studies concerningL. guyanensismetacyclogenesis and no technique for obtaining metacyclic promastigotes for this species is presently available. Here, we have studiedL. guyanensismetacyclogenesis in axenic culture, describing the main changes that occur during this process, namely, in morphology and size, sensitivity to complement-mediated lysis, surface carbohydrates and infectivity to macrophages. We have shown that metacyclogenesis inL. guyanensispromastigotes is basically complete on the 4thday of culture, as determined by decreased body size, increased flagellum length, resistance to complement-mediated lysis and infectivity. We have also found that only a fraction of the parasites is agglutinated byBauhinia purpurealectin. The non-agglutinated parasites, which also peaked on the 4thday of culture, had all morphological traits typical of the metacyclic stage. This is the first report describing metacyclogenesis inL. guyanensisaxenic promastigotes and a simple and efficient method for the purification of metacyclic forms. Furthermore, a model of human macrophage infection withL. guyanensiswas established.