ArticleMalaria journal2013
In vitro chloroquine resistance for Plasmodium vivax isolates from the Western Brazilian Amazon.
Article in Malaria journal, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 29 papers, 1 of them a synthesis that pooled it.
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Who cites it
29 citing papers in PubMed, 1 synthesis or guideline pooled it, 44 citations in OpenAlex.
- 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
- The Landscape of Malaria in a Five-Decade Institution in the State of Amazonas: Historical Trends, Scientific Contributions, and Research Priorities.Revista da Sociedade Brasileira de Medicina Tropical · 2026Review
- AreBiomedicines · 2024Article
- A review of malaria molecular markers for drug resistance inFrontiers in cellular and infection microbiology · 2023Review
- Monitoring Plasmodium vivax resistance to antimalarials: Persisting challenges and future directions.International journal for parasitology. Drugs and drug resistance · 2021Review
- Molecular Surveillance andFrontiers in cellular and infection microbiology · 2021Article
- Antimalarial Drug Resistance and Implications for the WHO Global Technical Strategy.Current epidemiology reports · 2021Review
- Influence ofAntimicrobial agents and chemotherapy · 2020Article
- Ex vivo susceptibilities of Plasmodium vivax isolates from the China-Myanmar border to antimalarial drugs and association with polymorphisms in Pvmdr1 and Pvcrt-o genes.PLoS neglected tropical diseases · 2020Article
- Evolution of the Plasmodium vivax multidrug resistance 1 gene in the Greater Mekong Subregion during malaria elimination.Parasites & vectors · 2020Article
- A comprehensive analysis of malaria transmission in Brazil.Pathogens and global health · 2019Article
- Genetic diversity of the Plasmodium vivax multidrug resistance 1 gene in Thai parasite populations.Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases · 2018Article
- Genetic diversity of the Plasmodium vivax phosphatidylinositol 3-kinase gene in two regions of the China-Myanmar border.Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases · 2018Article
- Enhanced Ex Vivo Plasmodium vivax Intraerythrocytic Enrichment and Maturation for Rapid and Sensitive Parasite Growth Assays.Antimicrobial agents and chemotherapy · 2018Article
- Simultaneous detection of Plasmodium vivax dhfr, dhps, mdr1 and crt-o resistance-associated mutations in the Colombian Amazonian region.Malaria journal · 2018Article
- Further evaluation of the NWF filter for the purification of Plasmodium vivax-infected erythrocytes.Malaria journal · 2017Article
- Article
- Plasmodium vivax multidrug resistance-1 gene polymorphism in French Guiana.Malaria journal · 2016Article
- Plasmodium vivax mdr1 genotypes in isolates from successfully cured patients living in endemic and non-endemic Brazilian areas.Malaria journal · 2016Article
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Authors and funding
10 authors at 4 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundChloroquine (CQ) and primaquine (PQ) are still the drugs of choice to treat Plasmodium vivax malaria in many endemic areas, Brazil included. There is in vivo evidence for the P. vivax resistance to CQ in the Brazilian Amazon, where the increase in the proportion of P. vivax malaria parallels the increase of unusual clinical complications related to this species. In this study, in vitro CQ and mefloquine (MQ)-susceptibility of P. vivax isolates from the Western Brazilian Amazon was tested using the double-site enzyme-linked lactate dehydrogenase immunodetection (DELI) assay.
methodsA total of 112 P. vivax isolates were tested in vitro for CQ-susceptibility and out of these 47 were also tested for MQ-susceptibility. The DELI assay was used to detect P. vivax growth at 48-hour short-term culture in isolates with ring stages ranging from 50 to %. Each isolate was tested in triplicate and geometric means of IC50's was obtained. Nineteen isolates were genetically characterized for pvdhfr, pvmrp1, pvmdr1 and pvdhps candidate genes likely related to CQ resistance (10 with IC50<40 nM and 9 with IC50 >100 nM).
resultsTwelve out of 112 isolates were considered resistant to CQ, resulting in 10.7% (IC95% 5.0-16.4), while 3 out of 47 (6.4%; IC95% 0.0-12.8) were resistant to MQ. A discrete correlation was observed between IC50's of CQ and MQ (Spearman=0.294; p=0.045). For pvdhps gene, a non-synonymous mutation was found at codon 382 (S→C) in 5/8 CQ-sensitive samples and 1/9 CQ-resistant samples (p=0.027). The other molecular markers were not associated to CQ-susceptibility.
conclusionsIn vitro CQ-resistance estimated in this study, estimated by the DELI test, was very similar to that observed in clinical trials, suggesting that in vitro procedures developed by capable local laboratories are useful in the surveillance of CQ-resistance in the Amazon; concurrent Amazon P. vivax strains with both CQ and MQ resistance may be common; and a non-synonymous mutation at pvdhps codon 382 (S→C) was associated to in vitro susceptibility to CQ, needing further studies to be confirmed.
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