Genomic sequencing of artemisinin-resistant parasite lines generated in the lab.

To characterize artemisinin resistance mechanisms, we generated dihydroartemisinin (DHA) resistance in the P. falciparum Dd2 strain using a stepwise increment in DHA concentration over a period of two years. The resistant parasites showed prolonged ring stage phenotype and low susceptibility to DHA as indicated by consistently high ring-stage survival values. In addition, the resistance was also evident at the later stages as revealed by high mature-stage survival rates and a significant increase in the half-maximal inhibitory concentration (IC50) values to ART and other related drugs in an in vitro assay.