Figure 2. Ex vivo/in vitro antimalarial drug susceptibility and Pfmdr1 copy number variation of PfC2A across Aotus passages.

(A,B) IC₅₀ antimalarial drug nM concentration bar plots of reference strains D6 (white bar), in vitro culture adapted TM90C2A (blue bar) and pfC2A Aotus adapted passage levels II (black bar) and X (red bar). Drug IC50 nM resistance threshold (black line). Mean ± sample SEM (see also Table S1). (C) DHA drug susceptibility based on RSA. Survival percentage = DHA treated parasites/DMSO treated parasites × 100. Red bar represents survival of artemisinin resistant positive control strain KH001-029, D6 is included as negative reference strain. Significant survival threshold (black line) is set at 1% as in Witkowski et al.²⁴. (D) Passage level pfmdr1 copy number fold change of a Plasmodium falciparum C2A clone during adaption to Aotus monkeys. P. falciparum strains with two pfmdr1 gene copies are considered resistant to MQ. Mean ± sample SEM. Dashed line indicates threshold for pfmdr1 CN level indicative of MQ resistance. Dotted line indicates threshold for pfmdr1 CN level indicative of MQ sensitivity. MQ = Mefloquine; CQ = Chloroquine; ATV = Atovaquone; AS = Artesunate; QHS = Artemisinin; DHA = Dihydroartemisinin. p = Mann-Whitney U significance t test unpaired samples. ***p < 0.005; **p < 0.05.