Publication
Title
In vitro sensitivity testing of **Leishmania** clinical field isolates: preconditioning of promastigotes enhances infectivity for macrophage host cells
Author
Abstract
Diagnostic material from patients with leishmaniasis is generally available as promastigotes, and proper testing for susceptibility to first-line drugs by the intracellular amastigote assay is frequently hampered by the poor infectivity of the promastigotes for the macrophage host cell. Several conditions for optimization of the in vitro metacyclogenesis and cell infectivity of Leishmania donovani, L. guyanensis, and L. braziliensis field strains obtained from patients receiving standard antimony medication were investigated. Triggering log-phase promastigotes to become amastigote-like by increasing the temperature or acidifying the culture medium was not successful. Adequate metacyclogenesis and the highest levels of macrophage infection were obtained after 5-day-old late-log-phase promastigote cultures were preconditioned at 25°C to pH 5.4 for 24 h in Schneider's medium prior to infection. The susceptibility assay with primary peritoneal mouse macrophages included pentavalent antimony (SbV; sodium stibogluconate), trivalent antimony (SbIII; potassium antimonyl tartrate), miltefosine, and the experimental drug PX-6518. All strains were sensitive to miltefosine (50% inhibitory concentration [IC50] < 10 µM) and PX-6518 (IC50 < 2 µg/ml) but showed distinct susceptibility to SbV and/or SbIII, depending on whether they were derived from cured, relapse, or nonresponder patients. Within the available set of Leishmania species and strains, simultaneous SbV-SbIII resistance was clearly associated with treatment failure; however, a larger set of isolates is still needed to judge the predictive value of SbV-SbIII susceptibility profiling on treatment outcome. In conclusion, the proposed conditioning protocol further contributes toward a more standardized laboratory model for evaluation of the drug sensitivities of field isolates.
Language
English
Source (journal)
Antimicrobial agents and chemotherapy. - Washington, D.C.
Publication
Washington, D.C. : 2009
ISSN
0066-4804
Volume/pages
53:12(2009), p. 5197-5203
ISI
000271834400035
Full text (Publisher's DOI)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 19.11.2009
Last edited 17.09.2017
To cite this reference