Evidence map›Paper›PMID 32867773›Full record

ArticleMalaria journal2020

Genetic analysis of the orthologous crt and mdr1 genes in Plasmodium malariae from Thailand and Myanmar.

Yupawadee Pimpat, Naowarat Saralamba, Usa Boonyuen, Sasithon Pukrittayakamee, Francois Nosten, Frank Smithuis, Nicholas P J Day, Arjen M Dondorp, Mallika Imwong

Open access · goldAbstract read
In one paragraph

Article in Malaria journal, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
0.2field-weighted citation impact, top 40% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed, 5 citations in OpenAlex.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors at 2 institutions in 3 countries.

Yupawadee PimpatDepartment of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Naowarat SaralambaDepartment of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. naowarat.sar@mahidol.ac.th.ORCID http://orcid.org/0000-0002-4987-8442
Usa BoonyuenDepartment of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Sasithon PukrittayakameeMahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Francois NostenShoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand.
Frank SmithuisCentre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
Nicholas P J DayMahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Arjen M DondorpMahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Mallika ImwongDepartment of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Mahidol University · THNuffield Orthopaedic Centre · GB

Funding

Faculty of Tropical Medicine, Mahidol University Research Fund 2017
6 · The paper itself

Abstract

backgroundPlasmodium malariae is a widely spread but neglected human malaria parasite, which causes chronic infections. Studies on genetic polymorphisms of anti-malarial drug target genes in P. malariae are limited. Previous reports have shown polymorphisms in the P. malariae dihydrofolate reductase gene associated with pyrimethamine resistance and linked to pyrimethamine drug pressure. This study investigated polymorphisms of the P. malariae homologous genes, chloroquine resistant transporter and multidrug resistant 1, associated with chloroquine and mefloquine resistance in Plasmodium falciparum.

methodsThe orthologous P. malariae crt and mdr1 genes were studied in 95 patients with P. malariae infection between 2002 and 2016 from Thailand (N = 51) and Myanmar (N = 44). Gene sequences were analysed using BioEdit, MEGA7, and DnaSP programs. Mutations and gene amplifications were compared with P. falciparum and Plasmodium vivax orthologous genes. Protein topology models derived from the observed pmcrt and pmmdr1 haplotypes were constructed and analysed using Phyre2, SWISS MODEL and Discovery Studio Visualization V 17.2.

resultsTwo non-synonymous mutations were observed in exon 2 (H53P, 40%) and exon 8 (E278D, 44%) of pmcrt. The topology model indicated that H53P and E278D were located outside of the transmembrane domain and were unlikely to affect protein function. Pmmdr1 was more diverse than pmcrt, with 10 non-synonymous and 3 synonymous mutations observed. Non-synonymous mutations were located in the parasite cytoplasmic site, transmembrane 11 and nucleotide binding domains 1 and 2. Polymorphisms conferring amino acid changes in the transmembrane and nucleotide binding domains were predicted to have some effect on PmMDR1 conformation, but were unlikely to affect protein function. All P. malariae parasites in this study contained a single copy of the mdr1 gene.

conclusionsThe observed polymorphisms in pmcrt and pmmdr1 genes are unlikely to affect protein function and unlikely related to chloroquine drug pressure. Similarly, the absence of pmmdr1 copy number variation suggests limited mefloquine drug pressure on the P. malariae parasite population, despite its long time use in Thailand for the treatment of falciparum malaria.

Indexed as

Polymorphism, GeneticATP-Binding Cassette, Sub-Family C ProteinsChloroquineDrug ResistanceInsecticidesMefloquineMembrane Transport ProteinsMyanmarPlasmodium malariaeProtozoan ProteinsThailandATP-Binding Cassette, Sub-Family C ProteinsChloroquineInsecticidesMefloquineMembrane Transport ProteinsProtozoan ProteinsChloroquine resistant transporterMalariaMultidrug resistance proteins 1Plasmodium malariae

Identifiers

PMID32867773
PMCPMC7461347
OpenAlexW3082880696

What OpenQuestion holds

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LicenceCC BY
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.