Characterization of PfCRT F145I in piperaquine-resistant Plasmodium falciparum isolates from Cambodia through zinc-finger nuclease-mediated gene editing

Abstract

ACTs are the first-line treatment for clinical malaria in the malaria-endemic world and have reduced malaria-associated mortality and morbidity. However, the recent emergence of Plasmodium falciparum that is resistant to both the artemisinins and key partner drugs, piperaquine, in Cambodia and nearby countries in GMS poses a threat to the control and elimination of malaria. Identification and validation of molecular markers of antimalarial drug resistance provide surveillance tools to monitor resistance and inform drug policy decisions and insights into the molecular mechanisms underlying resistance. Previous studies have found that F145I mutation within the PfCRT and plasmepsin2/3 gene copy number are associated with resistance to piperaquine. When PfCRT F145I is introduced into Dd2 of P. falciparum, it confers piperaquine resistance. In this study, we will use gene-editing approaches to remove F145I from field isolates that contain both this mutation and amplified plasmepsin2/3, to quantify the effect on malaria parasite susceptibility to piperaquine.