The development of drug resistance is reducing the efficiency of antifolates as antimalarials. This phenomenon has been linked to the occurrence of mutations in the parasite's dihydrofolate reductase (DHFR). In this way, the resistance to pyrimethamine and cycloguanil, two potent inhibitors of P. falciparum DHFR, is mainly related to mutations (single and crossed) at residues 16, 51, 59, 108 and 164 of the enzyme. In this work, we have refined a recently proposed homology-model of P. falciparum DHFR, and the resulting structure was used to obtain models for 14 mutant enzymes, employing molecular modeling. Ternary complexes of the mutant enzymes with these inhibitors have been superimposed to equivalent ternary complexes of the wild-type enzyme, allowing the proposition of hypotheses for the role of each mutation in drug resistance. Based on these results, possible reasons for antifolate resistance have been proposed.
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http://dx.doi.org/10.1016/s0301-4622(02)00077-7 | DOI Listing |
BMC Infect Dis
January 2025
Centre for Geographic Medicine Research (Coast), Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.
Background: To understand the emergence and spread of drug-resistant parasites in malaria-endemic areas, accurate assessment and monitoring of antimalarial drug resistance markers is critical. Recent advances in next-generation sequencing (NGS) technologies have enabled the tracking of drug-resistant malaria parasites.
Methods: In this study, we used Targeted Amplicon Deep Sequencing (TADS) to characterise the genetic diversity of the Pfk13, Pfdhfr, Pfdhps, and Pfmdr1 genes among primary school-going children in 15 counties in Kenya (Bungoma, Busia, Homa Bay, Migori, Kakamega, Kilifi, Kirinyaga, Kisii, Kisumu, Kwale, Siaya, Tana River, Turkana, Vihiga and West Pokot).
Wellcome Open Res
June 2024
MARCAD Program, The biotechnology Centre, University of Yaounde I, Yaounde, Centre, P 0 Box 8094, Cameroon.
Background: Antimalarial drug resistance is a major challenge in the fight against malaria. Cameroon implemented seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine and amodiaquine (SPAQ) to over 1.5 million children aged 3-59 months from 2016, raising concerns whether drug pressure may lead to a selection of known parasite resistance mutations.
View Article and Find Full Text PDF3 Biotech
December 2024
Department of Pharmaceutical Sciences, Dibrugarh University, Dibrugarh, Assam 786004 India.
Unlabelled: Malaria is a significant global public health issue, particularly prevalent in Africa, Asia, and Latin America, necessitating urgent research into novel and efficient therapies. In the current research, we have designed pyridine substituted pyrazole 1,3,5-triazine derivatives as antimalarials. A library including 300 compounds, designated as (-), has been generated using a variety of aliphatic and aromatic amines.
View Article and Find Full Text PDFSci Rep
November 2024
Department of Parasite Disease Control and Prevention, Henan Provincial Key Laboratory of Pathogenic Microbiology, Henan Provincial Medical Key Laboratory of Parasitic Diseases and Vector, Henan Province Center for Disease Control and Prevention, Zhengzhou, People's Republic of China.
Background: Malaria in pregnancy is a major public health issue, particularly among vulnerable populations in malaria-endemic sub-Saharan African countries. To mitigate its risks, WHO recommends sulphadoxine-pyrimethamine (SP) for chemoprevention and artemisinin-based combination therapy (ACT) to treat uncomplicated malaria. These interventions have helped to alleviate the risk associated with malaria in pregnancy; however, in the context of the emergence of SP- and ACT-resistant , maintained efficacy is under threat.
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