Molecular Investigation of Genetic Signatures of Selection in Plasmodium falciparum Actin-Binding Protein Coronin, Cysteine Desulfurase, and Plasmepsin 2 Gene in Mbita Field Isolates, Western Kenya

Abstract

Background: Plasmodium falciparum (Pf) resistance to antimalarial drugs is a major impediment to malaria control. The Pf.Kelch 13 (PfK13) gene has been largely reported to be associated with artemisinin resistance. However, recent studies have shown artemisinin resistance without Kech13 mutations suggesting the implication of others genes in artemisinin resistance. In this current study, we focused on mutations in Pf.actin-binding protein coronin, Pf.cysteine desulfurase and Pf.plasmepsin 2 gene, three putative candidates recently were reported to be involved in artemisinin, lumefantrine and piperaquine resistance respectively. Method: Archived blood samples previously collected from asymptomatic school children from December 2016 to October 2018 were used in this study. Genomic DNA was extracted using ISOLATE II Genomic DNA kit. After PCR amplification, amplicons were purified and sequenced by capillary sequencing. Reads were analyzed for the identification of point mutations previously reported to be involved in drug selection. Results: Mutations R100K, and G50E involved in reduced artemisinin susceptibility were detected in Pfcoronin. From 2016/17 to 2018 the allele 100k increased frequency (11.2%); while 50E was only observed in 2018 time point reaching 11.1%. Lumefantrine selection marker K65, in codon (K65Q) was observed at 14.2% in Pfcysteine desulfurase, and the mutant’ allele 65Q gradually increased frequency from 28.5% in 2016/17 to 57.1% in 2018. Pf.plasmepsin 2 was the less polymorphic gene. Several other polymorphism codons and single nucleotide variants were detected. Conclusion: The findings indicate the presence of mutations associated with reduced artemisinin susceptibility and lumefantrine selection marker. Therefore, the results call for continuous monitoring of molecular makers in Mbita parasites.