Publication
Title
Lack of correlation between the promastigote back-transformation assay and miltefosine treatment outcome
Author
Abstract
Objectives Widespread antimony resistance in the Indian subcontinent has enforced a therapy shift in visceral leishmaniasis treatment primarily towards miltefosine and secondarily also towards paromomycin. In vitro selection of miltefosine resistance in Leishmania donovani turned out to be quite challenging. Although no increase in IC50 was detected in the standard intracellular amastigote susceptibility assay, promastigote back-transformation remained positive at high miltefosine concentrations, suggesting a more resistant phenotype. This observation was explored in a large set of Nepalese clinical isolates from miltefosine cure and relapse patients to assess its predictive value for patient treatment outcome. Methods The predictive value of the promastigote back-transformation for treatment outcome of a set of Nepalese L. donovani field isolates (n = 17) derived from miltefosine cure and relapse patients was compared with the standard susceptibility assays on promastigotes and intracellular amastigotes. Results In-depth phenotypic analysis of the clinical isolates revealed no correlation between the different susceptibility assays, nor any clear link to the actual treatment outcome. In addition, the clinical isolates proved to be phenotypically heterogeneous, as reflected by the large variation in drug susceptibility among the established clones. Conclusions This in vitro laboratory study shows that miltefosine treatment outcome is not necessarily exclusively linked with the susceptibility profile of pre-treatment isolates, as determined in standard susceptibility assays. The true nature of miltefosine treatment failures still remains ill defined.
Language
English
Source (journal)
The journal of antimicrobial chemotherapy. - London, 1975, currens
Publication
London : 2015
ISSN
0305-7453 [print]
1460-2091 [online]
Volume/pages
70:11(2015), p. 3023-3026
ISI
000368245500013
Full text (Publishers DOI)
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UAntwerpen
Faculty/Department
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Publication type
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Affiliation
Publications with a UAntwerp address
External links
Web of Science
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Creation 14.08.2015
Last edited 27.03.2017
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