scholarly journals In vitro susceptibility of Leishmania infantum strains isolated from Spanish HIV-positive patients to Abelcet and Fungizone

2002 ◽  
Vol 50 (2) ◽  
pp. 304-306 ◽  
Author(s):  
J. E. Pinero
Keyword(s):  
Leishmania Infantum ◽  
Hiv Positive ◽  
In Vitro Susceptibility

scholarly journals In Vitro Susceptibility to Miltefosine of Leishmania infantum (syn. L. chagasi) Isolates from Different Geographical Areas in Brazil

2021 ◽  
Vol 9 (6) ◽  
pp. 1228
Author(s):  
Caroline Ricce Espada ◽  
Erica V. de Castro Levatti ◽  
Mariana Côrtes Boité ◽  
Dorcas Lamounier ◽  
Jorge Alvar ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Oral Drug ◽  
Efficacy And Safety ◽  
In Vitro Susceptibility ◽  
Intracellular Amastigotes ◽  
Geographic Regions ◽  
Therapeutic Tools ◽  
Cure Rates ◽  
Intracellular Amastigote

Treatment of visceral leishmaniasis in Brazil still relies on meglumine antimoniate, with less than ideal efficacy and safety, making new therapeutic tools an urgent need. The oral drug miltefosine was assayed in a phase II clinical trial in Brazil with cure rates lower than previously demonstrated in India. The present study investigated the susceptibility to miltefosine in 73 Brazilian strains of Leishmania infantum from different geographic regions, using intracellular amastigote and promastigote assays. The EC50 for miltefosine of 13 of these strains evaluated in intracellular amastigotes varied between 1.41 and 4.57 μM. The EC50 of the 73 strains determined in promastigotes varied between 5.89 and 23.7 μM. No correlation between in vitro miltefosine susceptibility and the presence of the miltefosine sensitive locus was detected among the tested strains. The relatively low heterogeneity in miltefosine susceptibility observed for the 73 strains tested in this study suggests the absence of decreased susceptibility to miltefosine in Brazilian L. infantum and does not exclude future clinical evaluation of miltefosine for VL treatment in Brazil.

scholarly journals Treatment of canine visceral leishmaniasis with Milteforan™ induces Leishmania infantum resistance to miltefosine and amphotericin B

2021 ◽  
Author(s):  
Gustavo Gonçalves ◽  
Monique Paiva Campos ◽  
Alessandra Silva Gonçalves ◽  
Lia Carolina Soares Medeiros ◽  
Fabiano Borges Figueiredo
Keyword(s):  
Visceral Leishmaniasis ◽  
Amphotericin B ◽  
Leishmania Infantum ◽  
Cross Resistance ◽  
Canine Visceral Leishmaniasis ◽  
In Vitro Susceptibility ◽  
Meglumine Antimoniate ◽  
Parasite Fitness ◽  
The Impact

Visceral leishmaniasis (VL) is the most severe form of leishmaniasis and is caused by Leishmania infantum in the Americas. Since the use of Milteforam™ was authorized to treat canine visceral leishmaniasis (CVL) in Brazil in 2017, there has also been fear of the emergence of parasites resistant to this drug and, through cross-resistance mechanisms, to meglumine antimoniate and amphotericin B. Additionally, the literature shows that acquisition of resistance is followed by increased parasite fitness, with higher rates of proliferation, infectivity and metacyclogenesis, which are determining factors for parasite virulence. In this context, this study aims to analyze the impact of treating a dog with Milteforan™ on the generation of parasites resistant to miltefosine, meglumine antimoniate, and amphotericin B. To this end, in vitro susceptibility tests were conducted against these drugs with T0 (parasites isolated from the dog before treatment with Milteforan™), T1 (after one course of treatment), and T2 (after two courses of treatment) isolates. The rates of cell proliferation, infectivity, and metacyclogenesis of the isolates were also evaluated. The results indicate a gradual increase in parasite resistance to miltefosine and amphotericin B with increasing the number of treatment courses. A trend increase in the metacyclogenesis rate of the parasites was also observed as drug resistance increased. Therefore, treatment of CVL with Milteforan™ induces resistance to miltefosine and amphotericin B as well as changes in parasite fitness, and may have an impact on animal and human public health.

scholarly journals Increased Leishmania infantum resistance to miltefosine and amphotericin B after treatment of a dog with miltefosine and allopurinol

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Gustavo Gonçalves ◽  
Monique Paiva Campos ◽  
Alessandra Silva Gonçalves ◽  
Lia Carolina Soares Medeiros ◽  
Fabiano Borges Figueiredo
Keyword(s):  
Amphotericin B ◽  
Leishmania Infantum ◽  
Resistance Mechanisms ◽  
Canine Leishmaniasis ◽  
Cross Resistance ◽  
In Vitro Susceptibility ◽  
Meglumine Antimoniate ◽  
Number Of Treatment ◽  
The Impact

Abstract Background Leishmania infantum is the most important etiological agent of visceral leishmaniasis in the Americas and Mediterranean region, and the dog is the main host. Miltefosine was authorized to treat canine leishmaniasis (CanL) in Brazil in 2017, but there is a persistent fear of the emergence of parasites resistant not only to this drug but, through cross-resistance mechanisms, also to meglumine antimoniate and amphotericin B. Additionally, the literature shows that acquisition of resistance is followed by increased parasite fitness, with higher rates of proliferation, infectivity and metacyclogenesis, which are drivers of parasite virulence. In this context, the aim of this study was to analyze the impact of treating a dog with miltefosine and allopurinol on the generation of parasites resistant to miltefosine, amphotericin B and meglumine antimoniate. Methods In vitro susceptibility tests were conducted against miltefosine, amphotericin B and meglumine antimoniate with T0 (parasites isolated from a dog before treatment with miltefosine plus allopurinol), T1 (after 1 course of treatment) and T2 (after 2 courses of treatment) isolates. The rates of cell proliferation, infectivity and metacyclogenesis of the isolates were also evaluated. Results The results indicate a gradual increase in parasite resistance to miltefosine and amphotericin B with increasing the number of treatment courses. An increasing trend in the metacyclogenesis rate of the parasites was also observed as drug resistance increased. Conclusion The data indicates an increased L. infantum resistance to miltefosine and amphotericin B after the treatment of a dog with miltefosine plus allopurinol. Further studies with a larger number of L. infantum strains isolated from dogs with varied immune response profiles and undergoing different treatment regimes, are advocated. Graphical Abstract

Novel Scaffolds for Leishmania infantum Trypanothione Reductase Inhibitors Derived from Brazilian Natural Products Biodiversity

2021 ◽  
Vol 18 (4) ◽  
pp. 398-418
Author(s):  
Vinícius Guimarães da Paixão ◽  
Samuel Silva da Rocha Pita
Keyword(s):  
Natural Products ◽  
Leishmania Infantum ◽  
In Vitro Assays ◽  
Current Therapy ◽  
Pharmacokinetic Analysis ◽  
Trypanothione Reductase ◽  
Resistant Species ◽  
Reductase Inhibitors ◽  
Thiol Redox

Background: Leishmania infantum causes the most lethal form of Leishmaniasis: Visceral leishmaniasis. Current therapy for this disease is related to the development of drug-resistant species and toxicity. Trypanothione Reductase (LiTR), a validated target for the drug discovery process, is involved with parasites' thiol-redox metabolism. Objective: In this study, through Virtual Screening employing two distinct Natural Products Brazilian databases, we aimed to identify novel inhibitor scaffolds against LiTR. Results: Thus, the “top 10” LiTR-ligand energies have been selected and their interaction profiles into LiTR sites through the AuPosSOM server have been verified. Finally, Pred-hERG, Aggregator Advisor, FAF-DRUGS, pkCSM and DataWarrior were employed and their results allowed us to evaluate, respectively, the cardiotoxicity, aggregation capacity, presence of false-positive compounds (PAINS) and their toxicities. Conclusion: Three molecules that overcame the in silico pharmacokinetic analysis and have a good interaction with LiTR, were chosen to use in vitro assays hoping that our computational results reported here would aid the development of new anti-leishmanial compounds.

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