Selection of Cytochrome b Mutants Is Rare among Plasmodium falciparum Patients Failing Treatment with Atovaquone-Proguanil in Cambodia

Atovaquone-proguanil remains effective against multidrug-resistant in Southeast Asia, but resistance is mediated by a single point mutation in cytochrome ( ) that can arise during treatment. Among 14 atovaquone-proguanil treatment failures in a clinical trial in Cambodia, only one recrudescence harbored the mutation Y268C. Deep sequencing did not detect the mutation at baseline or in the first 3 days of treatment, suggesting that it arose Further sequencing across similarly found no low-frequency mutations that were up-selected from baseline to recrudescence. Copy number amplification in dihydroorotate dehydrogenase (DHODH) and cytb as markers of atovaquone tolerance was also absent. mutation played a minor role in atovaquone-proguanil treatment failures in an active comparator clinical trial.