Transgenic pyrimethamine-resistant plasmodium falciparum reveals transmission-blocking potency of P218, a novel antifolate candidate drug

Antimalarial drugs capable of targeting multiple parasite stages, particularly the transmissible can be valuable tools for advancing malaria elimination agenda. Current antifolate such as pyrimethamine inhibit replicative stages in both humans and mosquitoes, but resistance remains a challenge. The lack reliable gametocyte-producing, antifolate-resistant Plasmodium falciparum laboratory strain hinders study new compounds that overcome including development mosquito. We used clustered regularly interspaced short palindromic repeats-Cas9 genome editing to develop transgenic gametocyte-producing P. with quadruple mutations (N51I, C59R, S108N, I164L) dihydrofolate reductase (dhfr) gene, using NF54 parental strain. parasites exhibited while maintaining their activity. then demonstrated could no longer male gametocyte exflagellation parasite. In contrast, P218, novel antifolate, designed resistance, potently inhibited exflagellation. IC50 P218 was five times lower than asexual stage half maximal inhibitory concentration (IC50), suggesting strong barrier transmission P218-resistant parasites. pyrimethamine-resistant is robust system evaluating against non-asexual development.