Geographical spread and structural basis of sulfadoxine-pyrimethamine drug-resistant malaria parasites

• Published in: International journal for parasitology 2021-06, Vol.51 (7), p.505-525
• Main Authors: Chaturvedi, Rini, Chhibber-Goel, Jyoti, Verma, Ishika, Gopinathan, Sreehari, Parvez, Suhel, Sharma, Amit
• Format: Article
• Language: English
• Subjects: Antimalarials - pharmacology; DHFR; DHPS; Dihydropteroate Synthase - genetics; Drug Combinations; Drug Resistance; Genotype; Mutation; Plasmodium; Plasmodium falciparum - drug effects; Plasmodium falciparum - genetics; Pyrimethamine; Pyrimethamine - pharmacology; Sulfadoxine; Sulfadoxine - pharmacology; Tetrahydrofolate Dehydrogenase - genetics
• ISSN: 0020-7519; 1879-0135
• DOI: 10.1016/j.ijpara.2020.12.011

[Display omitted] •DHPS and DHFR are validated drug targets for sulfadoxine (sdx) and pyrimethamine (pyr) in plasmodial species.•Sdx-Pyr (SP) combination medicine is a widely used antimalarial therapy.•The spread of SP resistance is attributed to increasing numbers of mutations in DHPS and DHFR enzymes.•Surveillance of sdx and pyr resistance mutations in P. falciparum and P. vivax is critical. The global spread of sulfadoxine (Sdx, S) and pyrimethamine (Pyr, P) resistance is attributed to increasing number of mutations in DHPS and DHFR enzymes encoded by malaria parasites. The association between drug resistance mutations and SP efficacy is complex. Here we provide an overview of the geographical spread of SP resistance mutations in Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) encoded dhps and dhfr genes. In addition, we have collated the mutation data and mapped it on to the three-dimensional structures of DHPS and DHFR which have become available. Data from genomic databases and 286 studies were collated to provide a comprehensive landscape of mutational data from 2005 to 2019. Our analyses show that the Pyr-resistant double mutations are widespread in Pf/PvDHFR (P. falciparum ∼61% in Asia and the Middle East, and in the Indian sub-continent; in P. vivax ∼33% globally) with triple mutations prevailing in Africa (∼66%) and South America (∼33%). For PfDHPS, triple mutations dominate South America (∼44%), Asia and the Middle East (∼34%) and the Indian sub-continent (∼27%), while single mutations are widespread in Africa (∼45%). Contrary to the status for P. falciparum, Sdx-resistant single point mutations in PvDHPS dominate globally. Alarmingly, highly resistant quintuple and sextuple mutations are rising in Africa (PfDHFR-DHPS) and Asia (Pf/PvDHFR-DHPS). Structural analyses of DHFR and DHPS proteins in complexes with substrates/drugs have revealed that resistance mutations map proximal to Sdx and Pyr binding sites. Thus new studies can focus on discovery of novel inhibitors that target the non-substrate binding grooves in these two validated malaria parasite drug targets.