title: The sensitivity of clinical isolates of Leishmania from Peru and Nepal to miltefosine.
abstract: Clinical isolates of Leishmania, from visceral leishmaniasis (VL) cases in Nepal and from cutaneous leishmaniasis (CL) cases in Peru, were cultured using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to type species and strain. Promastigotes from 38 isolates, within eight passages from isolation, were used to infect mouse peritoneal macrophage cultures in vitro, and the amastigote sensitivity to miltefosine was determined. The concentration required to kill 50% of intracellular amastigotes from Nepalese VL isolates, all typed as Leishmania (L.) donovani (N = 24) from both Sbv responders and nonresponders, ranged from 8.7 to 0.04 microg/mL. In contrast, the concentration required to kill 50% intracellular amastigotes from isolates from Peru, typed as L.(V.) braziliensis (N = 8), was > 30 to 8.4 microg/mL, L.(V.) guyanensis (N = 2) > 30 to 1.9 microg/mL, L.(L.) mexicana (N = 1) > 30 microg/mL, and L. (V.) lainsoni (N = 4) was 3.4 to 1.9 microg/mL. This demonstrates a notable difference in the intrinsic sensitivity of Leishmania species to miltefosine in vitro. If this model can be correlated to therapeutic outcome, it may have implications for the interpretation of clinical trials.
authors.affiliation: Department of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Yardley
authors.forename: Simon L
authors.initials: SL
authors.lastname: Croft
authors.forename: Simonne
authors.initials: S
authors.lastname: De Doncker
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Dujardin
authors.forename: Siddhartha
authors.initials: S
authors.lastname: Koirala
authors.forename: Suman
authors.initials: S
authors.lastname: Rijal
authors.forename: Cesar
authors.initials: C
authors.lastname: Miranda
authors.forename: Alejandro
authors.initials: A
authors.lastname: Llanos-Cuentas
authors.forename: Francois
authors.initials: F
authors.lastname: Chappuis
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D006801:Humans; D007891:Leishmania / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D016773:Leishmaniasis, Cutaneous / Q000469:parasitology*; D007898:Leishmaniasis, Visceral / Q000469:parasitology*; D017737:Macrophages, Peritoneal / Q000469:parasitology; D051379:Mice; D009390:Nepal; D021261:Parasitic Sensitivity Tests / Q000379:methods; D010568:Peru; D010767:Phosphorylcholine / Q000031:analogs & derivatives* / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D000981:Antiprotozoal Agents; D010767:Phosphorylcholine; C039128:miltefosine