Identification of an in vitro artemisinin-resistant Plasmodium falciparum kelch13 R515K mutant parasite in Senegal

Abstract

The emergence of artemisinin partial resistance (ART-r) in <i>Plasmodium falciparum</i> malaria parasites has substantially compromised the efficacy of antimalarial treatments across southeast Asia (SE Asia). The spread of ART-r within the African continent could jeopardize past progress made in reducing worldwide malaria burden. A clinical index malaria case was identified in Kaolack, Senegal with persistent fever after complete artesunate-amodiaquine (ASAQ) treatment. Fifteen malaria-infected blood samples were collected by Institut Pasteur Dakar's Senegalese sentinel surveillance system, from different healthcare centers surrounding the index case. We have identified one <i>Plasmodium falciparum</i> clinical isolate carrying R515K mutation in the artemisinin resistance gene PfKelch13. CRISPR-Cas9 genome editing was carried out and transgenic Pf3D7Pfkelch13^R515K was tested for <i>in vitro</i> standard Ring-stage Survival Assay <i>(RSA</i> ^0-3hpi). Gene editing has confirmed that <i>PfKelch13^R515K</i> drove increased <i>in vitro</i> RSA^0-3hpi value. In this article, we report the functional significance of PfKelch13^R515K mutation in an African context.