title: Selection and phenotype characterization of potassium antimony tartrate-resistant populations of four New World Leishmania species.
abstract: In the present study, we selected in vitro populations of Leishmania Viannia guyanensis, L.V. braziliensis, L. Leishmania amazonensis and L.L. infantum chagasi that were resistant to potassium antimony tartrate (SbIII). The resistance index of these populations varied from 4- to 20-fold higher than that of their wild-type counterparts. To evaluate the stability of the resistance phenotype, these four resistant populations were passaged 37 to 47 times in a culture medium without SbIII. No change was observed in the resistance indexes of L.V. guyanensis (19-fold) and L.L. infantum chagasi (4-fold). In contrast, a decrease in the resistance index was observed for L.V. braziliensis (from 20- to 10-fold) and L.L. amazonensis (from 6- to 3-fold). None of the antimony-resistant populations exhibited cross-resistance to amphotericin B and miltefosine. However, the resistant populations of L.V. braziliensis, L.L. amazonensis and L.L. infantum chagasi were also resistant to paromomycin. A drastic reduction was observed in the infectivity in mice for the resistant L.V. guyanensis, L.L. amazonensis and L.V. braziliensis populations. The SbIII-resistant phenotype of L.V. braziliensis was stable after one passage in mice. Although the protocol of induction was the same, the SbIII-resistant populations showed different degrees of tolerance, stability, infectivity in mice and cross-resistance to antileishmanial drugs, depending on the Leishmania species.
authors.affiliation: Laboratório de Parasitologia Celular e Molecular, Centro de Pesquisas René Rachou-CPqRR/Fiocruz, Av. Augusto de Lima 1715, Caixa Postal 1743, CEP 30190-002, Belo Horizonte, MG, Brazil.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Liarte
authors.forename: Silvane M F
authors.initials: SM
authors.lastname: Murta
mesh_terms: D000666:Amphotericin B / Q000494:pharmacology; D000818:Animals; D000966:Antimony Potassium Tartrate / Q000494:pharmacology*; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D003470:Culture Media / Q000737:chemistry; D004351:Drug Resistance; D020128:Inhibitory Concentration 50; D007891:Leishmania / Q000187:drug effects* / Q000254:growth & development* / Q000302:isolation & purification / Q000472:pathogenicity; D007896:Leishmaniasis / Q000382:microbiology / Q000473:pathology; D008099:Liver / Q000469:parasitology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010303:Paromomycin / Q000494:pharmacology; D010641:Phenotype; D010767:Phosphorylcholine / Q000031:analogs & derivatives / Q000494:pharmacology; D012641:Selection, Genetic; D012692:Serial Passage; D013154:Spleen / Q000469:parasitology; D014774:Virulence
chemical_list: D000981:Antiprotozoal Agents; D003470:Culture Media; D010767:Phosphorylcholine; C039128:miltefosine; D010303:Paromomycin; D000666:Amphotericin B; D000966:Antimony Potassium Tartrate