Data on selected antimalarial drug resistance markers in Zambia

Temporal genomics in Southern Zambia shows rising prevalence of Plasmodium falciparum mutations linked to delayed clearance after artemisinin-lumefantrine treatment

The emergence of antimalarial drug resistance is an impediment to malaria control and elimination in Africa. Analysis of temporal trends in molecular markers of resistance is critical to inform policy makers and guide malaria treatment guidelines. In a low and seasonal transmission region of southern Zambia, we successfully genotyped 85.5% (389/455) of Plasmodium falciparum samples collected between 2013 and 2018 from 8 spatially clustered health centres using molecular inversion probes (MIPs) targeting key drug resistance genes. Aside from one sample from 2016 carrying K13 622I, no other World Health Organization-validated or candidate artemisinin partial resistance (ART-R) mutations were observed. However, in the more recent years (2016-2017) five novel K13-propeller-domain mutations, C532S, A578S, Q613E, D680N and G718S were identified at low prevalence. Moreover, 13% (CI, 9.6-17.2) of isolates had the AP2MU 160N mutation, which has been associated with delayed clearance following artemisinin combination therapy in Africa. This mutation increased in prevalence between 2015 and 2018 and bears a genomic signature of selection. During this time period, there was an increase in the MDR1 NFD haplotype that is associated with reduced susceptibility to lumefantrine. Sulfadoxine-pyrimethamine polymorphisms were near fixation. While validated ART-R mutations are rare, a mutation associated with slow parasite clearance in Africa appears to be under selection in southern Zambia.

Tetrahydropyridine appended 8-aminoquinoline derivatives: Design, synthesis, in silico, and in vitro antimalarial studies

Antimalarial drug resistance is a major obstacle in the ongoing quest against malaria. The disease affects half of the world's population. The majority of them are toddlers and pregnant women. Needed a potent compound to act on drug-resistant Pf at appropriate concentrations without endangering the host. Envisaged solving this issue through rational drug design by creating a novel hybrid drug possessing two pharmacophores that can act on two marvellous and independent aims within the cell. Synthesized a new series of substituted 4-phenyl-1,2,3,6-tetrahydropyridine (THP) 8-Aminoquinoline-based hybrid analogs which have been integrated with quinoline, chloroquine, pamaquine, and primaquine, which exhibited antimalarial activity against Pf. Out of thirteen 4-phenyl-1,2,3,6-THP appended 8-Aminoquinoline derivatives, the compounds 1j, 1e, 1b, and 1l have exhibited good antimalarial activity against chloroquine-sensitive (3D7) and chloroquine-resistant (RKL-9) strain with the minimum inhibitory concentration. Compound 1b was the most effective and showed consistently good potency against the drug-resistant (RKL-9) strain, although all other arrays showed good antimalarial efficacy. Additional docking and molecular dynamics studies were carried out at several targeting sites to quantify the structural parameters necessary for the activity.

Temporal genomic analysis of Plasmodium falciparum reveals increased prevalence of mutations associated with delayed clearance following treatment with artemisinin-lumefantrine in Choma District, Southern Province, Zambia

The emergence of antimalarial drug resistance is an impediment to malaria control and elimination in Africa. Analysis of temporal trends in molecular markers of resistance is critical to inform policy makers and guide malaria treatment guidelines. In a low and seasonal transmission region of southern Zambia, we successfully genotyped 85.5% (389/455) of Plasmodium falciparum samples collected between 2013-2018 from 8 spatially clustered health centres using molecular inversion probes (MIPs) targeting key drug resistance genes. Aside from one sample carrying K13 R622I, none of the isolates carried other World Health Organization-validated or candidate artemisinin partial resistance (ART-R) mutations in K13. However, 13% (CI, 9.6-17.2) of isolates had the AP2MU S160N mutation, which has been associated with delayed clearance following artemisinin combination therapy in Africa. This mutation increased in prevalence between 2015-2018 and bears a genomic signature of selection. During this time period, there was an increase in the MDR1 NFD haplotype that is associated with reduced susceptibility to lumefantrine. Sulfadoxine-pyrimethamine polymorphisms were near fixation. While validated ART-R mutations are rare, a mutation associated with slow parasite clearance in Africa appears to be under selection in southern Zambia.