ArticleMalaria journal2014
Plasmodium vivax and Plasmodium falciparum ex vivo susceptibility to anti-malarials and gene characterization in Rondônia, West Amazon, Brazil.
Article in Malaria journal, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 24 papers, 2 of them syntheses that pooled it.
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Who cites it
24 citing papers in PubMed, 2 syntheses or guidelines pooled it, 29 citations in OpenAlex.
- Pooled it
- Assessment of copy number variation in genes related to drug resistance in Plasmodium vivax and Plasmodium falciparum isolates from the Brazilian Amazon and a systematic review of the literature.Malaria journal · 2017Pooled it
- Monitoring the Efficacy of Chloroquine-Primaquine Therapy for Uncomplicated Plasmodium vivax Malaria in the Main Transmission Hot Spot of Brazil.Antimicrobial agents and chemotherapy · 2019Trial
- Antimalarial cytoskeletal targeting with broad apicomplexan activity.Proceedings of the National Academy of Sciences of the United States of America · 2026Article
- Efficacy, Structure-Activity Relationship, and Mode of Action Studies of a New Generation of Acridine/Acridone-Based Antimalarials.ACS infectious diseases · 2026Article
- Structure-Guided Optimization of Novel Inhibitors ofJournal of medicinal chemistry · 2026Article
- Fluorescent Marinoquinoline Derivative as Inhibitors ofJournal of medicinal chemistry · 2025Article
- A potent and selective reaction hijacking inhibitor of Plasmodium falciparum tyrosine tRNA synthetase exhibits single dose oral efficacy in vivo.PLoS pathogens · 2024Article
- Plasmodium vivax genomic surveillance in the Peruvian Amazon with Pv AmpliSeq assay.PLoS neglected tropical diseases · 2024Article
- Toxins from Animal Venoms as a Potential Source of Antimalarials: A Comprehensive Review.Toxins · 2023Review
- Article
- Fighting Plasmodium chloroquine resistance with acetylenic chloroquine analogues.International journal for parasitology. Drugs and drug resistance · 2022Article
- Discovery and Preclinical Pharmacology of INE963, a Potent and Fast-Acting Blood-Stage Antimalarial with a High Barrier to Resistance and Potential for Single-Dose Cures in Uncomplicated Malaria.Journal of medicinal chemistry · 2022Article
- Article
- Repositioning and Characterization of 1-(Pyridin-4-yl)pyrrolidin-2-one Derivatives asACS infectious diseases · 2021Article
- Monitoring Plasmodium vivax resistance to antimalarials: Persisting challenges and future directions.International journal for parasitology. Drugs and drug resistance · 2021Review
- Simultaneous detection of Plasmodium vivax dhfr, dhps, mdr1 and crt-o resistance-associated mutations in the Colombian Amazonian region.Malaria journal · 2018Article
- Promising approach to reducing Malaria transmission by ivermectin: Sporontocidal effect against Plasmodium vivax in the South American vectors Anopheles aquasalis and Anopheles darlingi.PLoS neglected tropical diseases · 2018Article
- Article
- Measuring ex vivo drug susceptibility in Plasmodium vivax isolates from Cambodia.Malaria journal · 2017Article
Corrections and comments
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Authors and funding
5 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundChloroquine (CQ), a cost effective antimalarial drug with a relatively good safety profile and therapeutic index, is no longer used by itself to treat patients with Plasmodium falciparum due to CQ-resistant strains. P. vivax, representing over 90% of malaria cases in Brazil, despite reported resistance, is treated with CQ as well as with primaquine to block malaria transmission and avoid late P. vivax malaria relapses. Resistance to CQ and other antimalarial drugs influences malaria control, thus monitoring resistance phenotype by parasite genotyping is helpful in endemic areas.
methodsA total of 47 P. vivax and nine P. falciparum fresh isolates were genetically characterized and tested for CQ, mefloquine (MQ) and artesunate (ART) susceptibility in vitro. The genes mdr1 and pfcrt, likely related to CQ resistance, were analyzed in all isolates. Drug susceptibility was determined using short-term parasite cultures of ring stages for 48 to 72 hour and thick blood smears counts. Each parasite isolate was tested with the antimalarials to measure the geometric mean of 50% inhibitory concentration.
resultsThe low numbers of P. falciparum isolates reflect the species prevalence in Brazil; most displayed low sensitivity to CQ (IC50 70 nM). However, CQ resistance was rare among P. vivax isolates (IC50 of 32 nM). The majority of P. vivax and P. falciparum isolates were sensitive to ART and MQ. One hundred percent of P. falciparum isolates carried non-synonymous mutations in the pfmdr1 gene in codons 184, 1042 and 1246, 84% in codons 1034 and none in codon 86, a well-known resistance mutation. For the pfcrt gene, mutations were observed in codons 72 and 76 in all P. falciparum isolates. One P. falciparum isolate from Angola, Africa, showing sensitivity to the antimalarials, presented no mutations. In P. vivax, mutations of pvmdr1 and the multidrug resistance gene 1 marker at codon F976 were absent.
conclusionAll P. falciparum Brazilian isolates showed CQ resistance and presented non-synonymous mutations in pfmdr1 and pfcrt. CQ resistant genotypes were not present among P. vivax isolates and the IC50 values were low in all samples of the Brazilian West Amazon.
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