Antimalarial Drug Resistance Mechanisms in Plasmodium falciparum

Plasmodium falciparum poses a persistent threat to malaria control due to its capacity to acquire and propagate mutations that compromise antimalarial efficacy. Central to this adaptability are alterations in membrane transporters, metabolic enzymes and regulatory proteins. The digestive vacuole-resident chloroquine resistance transporter (PfCRT) expels 4-aminoquinoline drugs, while polymorphisms in the multidrug resistance protein 1 (PfMDR1) adjust susceptibility to artemisinin partner drugs such as mefloquine and lumefantrine. Antifolate resistance arises from stepwise mutations in dihydrofolate reductase and dihydropteroate synthase, reducing drug binding. Copy number amplification of pfmdr1 further diminishes partner-drug potency. More recently, single-base mutations in the kelch13 propeller domain have conferred delayed clearance under artemisinin pressure by altering endocytic and proteostasis pathways. These mechanisms act in concert to undermine artemisinin-based combination therapies (ACTs), threatening global malaria elimination efforts and necessitating enhanced molecular surveillance, strategic drug deployment and the development of novel compounds targeting resistant parasites.

Research from Nature Portfolio

Recent studies have elucidated the molecular basis by which PfCRT senses vacuolar pH and coordinates drug transport. Alanine-scanning mutagenesis pinpointed a conserved glutamate residue that acts as a pH sensor, modulating the conformational cycle of PfCRT and affecting chloroquine efflux kinetics. Structural modelling and molecular dynamics simulations revealed an allosteric mechanism in which proton binding reduces drug transport, offering insights for compounds that might restore chloroquine susceptibility. In parallel, genome-wide sequencing of asymptomatic isolates from Mali tracked temporal shifts in resistance marker frequencies across the parasite population. Whole-genome analysis identified increased prevalence of lumefantrine and sulfadoxine-pyrimethamine resistance alleles, high multiclonality and genes under selective pressure. These findings provide a recent and region-specific snapshot of evolving resistance landscapes, informing tailored intervention strategies.

Antimalarial Drug Resistance Mechanisms in Plasmodium falciparum publication trend

The graph below shows the total number of articles in antimalarial drug resistance mechanisms in plasmodium falciparum across all publications each year (not limited to Nature Index journals).

Technical terms

Chloroquine resistance transporter (PfCRT): A digestive vacuole membrane protein whose mutations reduce chloroquine accumulation and mediate resistance.

Multidrug resistance protein 1 (PfMDR1): An ATP-binding cassette transporter affecting susceptibility to multiple partner drugs in ACT regimens.

Kelch13 propeller domain: A regulatory protein region where specific mutations cause delayed artemisinin clearance by altering parasite endocytosis.

Single-nucleotide polymorphism (SNP): A single-base change in the genome that can modify protein function and confer drug resistance.

Selective sweep: Rapid increase in frequency of a beneficial allele in a population, reducing genetic diversity around that locus.

References

1. pH-dependence of the Plasmodium falciparum chloroquine resistance transporter is linked to the transport cycle. Nature Communications (2023).
2. Genome-wide genetic variation and molecular surveillance of drug resistance in Plasmodium falciparum isolates from asymptomatic individuals in Ouélessébougou, Mali. Scientific Reports (2023).
3. Sanger sequencing and deconvolution of polyclonal infections: a quantitative approach to monitor drug-resistant Plasmodium falciparum. EBioMedicine (2024).
4. PfCRT mutations conferring piperaquine resistance in falciparum malaria shape the kinetics of quinoline drug binding and transport. PLOS Pathogens (2023).
5. Two decades of molecular surveillance in Senegal reveal rapid changes in known drug resistance mutations over time. Malaria Journal (2024).