Plasmodium falciparum
Mechanisms of ResistanceAssociations between Malaria-Preventive Regimens and Plasmodium falciparum Drug Resistance-Mediating Polymorphisms in Ugandan Pregnant WomenIntermittent preventive treatment in pregnancy (IPTp) with monthly sulfadoxine-pyrimethamine (SP) is recommended for malaria-endemic parts of Africa, but efficacy is compromised by resistance, and, in recent trials, dihydroartemisinin-piperaquine (DP) has shown better antimalarial protective efficacy. We utilized blood samples from a recent trial to evaluate selection by IPTp with DP or SP of...
Epidemiology and SurveillancePrevalence of Plasmodium falciparum Kelch 13 (PfK13) and Ubiquitin-Specific Protease 1 (pfubp1) Gene Polymorphisms in Returning Travelers from Africa Reported in Eastern ChinaDelayed clearance of Plasmodium falciparum by artemisinin-based combination therapies (ACTs) has already been observed for African isolates. Here, we aimed to investigate the prevalence, among travelers returning from African countries, of polymorphisms in two genes correlated with delayed parasite clearance (encoding...
Mechanisms of ResistanceAssociations between Aminoquinoline Resistance Genotypes and Clinical Presentations of Plasmodium falciparum Infection in UgandaMutations that mediate resistance of Plasmodium falciparum to aminoquinoline antimalarials are selected by prior drug use and may alter parasite fitness, but associations with clinical presentations are uncertain. We evaluated genotypes in samples from a case-control study of determinants of severe malaria in Ugandan children 4 months to 10 years of age. We studied...
SusceptibilityActivity of Epigenetic Inhibitors against Plasmodium falciparum Asexual and Sexual Blood StagesEarlier genetic and inhibitor studies showed that epigenetic regulation of gene expression is critical for malaria parasite survival in multiple life stages and a promising target for new antimalarials. We therefore evaluated the activity of 350 diverse epigenetic inhibitors against multiple stages of Plasmodium falciparum. We observed ≥90% inhibition at 10 μM for 28...
Mechanisms of ResistanceExperimentally Engineered Mutations in a Ubiquitin Hydrolase, UBP-1, Modulate In Vivo Susceptibility to Artemisinin and Chloroquine in Plasmodium bergheiAs resistance to artemisinins (current frontline drugs in malaria treatment) emerges in Southeast Asia, there is an urgent need to identify the genetic determinants and understand the molecular mechanisms underpinning such resistance. Such insights could lead to prospective interventions to contain resistance and prevent the eventual spread to other regions where malaria is endemic. Reduced susceptibility to artemisinin in Southeast...
Mechanisms of ResistanceA Histone Methyltransferase Inhibitor Can Reverse Epigenetically Acquired Drug Resistance in the Malaria Parasite Plasmodium falciparumMalaria parasites invade and replicate within red blood cells (RBCs), extensively modifying their structure and gaining access to the extracellular environment by placing the plasmodial surface anion channel (PSAC) into the RBC membrane. Expression of members of the cytoadherence linked antigen gene 3 (clag3) family is required for PSAC activity, a process that is regulated epigenetically. PSAC is a well-established route of...
Mechanisms of ResistanceEffect of Drug Pressure on Promoting the Emergence of Antimalarial-Resistant Parasites among Pregnant Women in GhanaThe continuous spread of antimalarial drug resistance is a threat to current chemotherapy efficacy. Therefore, characterizing the genetic diversity of drug resistance markers is needed to follow treatment effectiveness and further update control strategies. Here, we genotyped Plasmodium falciparum resistance gene markers associated with sulfadoxine-pyrimethamine (SP)...
SusceptibilityNovel Endochin-Like Quinolones Exhibit Potent In Vitro Activity against Plasmodium knowlesi but Do Not Synergize with ProguanilQuinolones, such as the antimalarial atovaquone, are inhibitors of the malarial mitochondrial cytochrome bc1 complex, a target critical to the survival of both liver- and blood-stage parasites, making these drugs useful as both prophylaxis and treatment. Recently, several derivatives of endochin have been optimized to produce novel quinolones that are active in vitro and in animal models. While these...
Experimental TherapeuticsWhole-Cell Phenotypic Screening of Medicines for Malaria Venture Pathogen Box Identifies Specific Inhibitors of Plasmodium falciparum Late-Stage Development and EgressWe report a systematic, cellular phenotype-based antimalarial screening of the Medicines for Malaria Venture Pathogen Box collection, which facilitated the identification of specific blockers of late-stage intraerythrocytic development of Plasmodium falciparum. First, from standard growth inhibition assays, we identified 173 molecules with antimalarial activity (50%...
Experimental TherapeuticsPreclinical Antimalarial Combination Study of M5717, a Plasmodium falciparum Elongation Factor 2 Inhibitor, and Pyronaridine, a Hemozoin Formation InhibitorAntimalarial drug resistance in the Plasmodium falciparum parasite poses a constant challenge for drug development. To mitigate this risk, new antimalarial medicines should be developed as fixed-dose combinations. Assessing the pharmacodynamic interactions of potential antimalarial drug combination partners during early phases of development is essential in developing...