Resistance has developed in Plasmodium malaria parasites to every antimalarial drug in clinical use, prompting the need to characterize the pathways mediating resistance. Here, we report a framework for assessing development of resistance of Plasmodium falciparum to new antimalarial therapeutics. We investigated development of resistance by P. falciparum to the dihydroorotate dehydrogenase (DHODH) inhibitors DSM265 and DSM267 in tissue culture and in a mouse model of P. falciparum infection. We found that resistance to these drugs arose rapidly both in vitro and in vivo. We identified 13 point mutations mediating resistance in the parasite DHODH in vitro that overlapped with the DHODH mutations that arose in the mouse infection model. Mutations in DHODH conferred increased resistance (ranging from 2- to ~400-fold) to DHODH inhibitors in P. falciparum in vitro and in vivo. We further demonstrated that the drug-resistant parasites carrying the C276Y mutation had mitochondrial energetics comparable to the wild-type parasite and also retained their fitness in competitive growth experiments. Our data suggest that in vitro selection of drug-resistant P. falciparum can predict development of resistance in a mouse model of malaria infection.

中文翻译：

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在小鼠感染模型中，体外选择预测疟原虫对二氢乳清酸脱氢酶抑制剂的抗性。

疟原虫对临床使用的每种抗疟药物都产生了耐药性，这促使需要对介导耐药性的途径进行表征。在这里，我们报告了一个框架，用于评估恶性疟原虫对新抗疟疗法的耐药性的发展。我们研究了恶性疟原虫在组织培养和恶性疟原虫感染小鼠模型中对二氢乳清酸脱氢酶 (DHODH) 抑制剂 DSM265 和 DSM267 的耐药性的发展。我们发现对这些药物的耐药性在体外和体内都迅速出现。我们在体外鉴定了 13 个介导寄生虫 DHODH 抗性的点突变，这些突变与小鼠感染模型中出现的 DHODH 突变重叠。DHODH 中的突变使 P. 中对 DHODH 抑制剂的抗性增加（范围从 2 到 ~400 倍）。体外和体内恶性疟原虫。我们进一步证明，携带 C276Y 突变的耐药寄生虫具有与野生型寄生虫相当的线粒体能量学，并且在竞争性生长实验中也保持了它们的适应性。我们的数据表明，抗药性恶性疟原虫的体外选择可以预测疟疾感染小鼠模型中抗药性的发展。