Artemisinin-based combination therapies are the most effective frontline treatments for Plasmodium falciparum malaria; therefore, the recent emergence and potential spread of artemisinin resistance in Southeast Asia, the epicenter of multidrug-resistant P. falciparum, has raised global concerns. Studies of clinical isolates from western Cambodia and genetically modified laboratory strains have established a causal link of artemisinin resistance with mutations in the K13 gene (Pf3D7_1343700), but the molecular mechanism of K13-mediated artemisinin resistance is not understood. Population genetic studies of parasites from Southeast Asia showed independent emergence of the K13 mutants in multiple parasite populations. To further address this urgent problem, this U.S.-China joint project will (1) identify novel molecular markers associated with artemisinin resistance through a genome-wide association study of P. falciparum parasite isolates from the China- Myanmar border area, where artemisinin family drugs have the longest history of deployment; (2) perform functional studies to determine the role of the K13 gene and its polymorphisms in artemisinin resistance; and (3) elucidate the molecular mechanism of artemisinin resistance through the identification of the molecular complex of the K13 protein. This joint project, built on a solid foundation of our past collaboration, encompasses the complementary expertise and resources from the collaborating institutions. The proposed studies will take advantage of the large archive of culture-adapted P. falciparum clinical isolates collected from the China-Myanmar border area and the significant inroad we have made into this field from our earlier collaborations. Information generated from this study will be highly useful for monitoring, curbing and deterring the spread of artemisinin resistance, and will have far-reaching impacts on both regional and global malaria elimination campaigns.

Public Health Relevance

Artemisinins are currently our last line of defense against multidrug-resistant malaria parasites. The emergence of malaria parasites resistant to the artemisinin family of drugs in the Greater Mekong Subregion of Southeast Asia is highly concerning. This U.S.-China joint project will address this urgent problem through mechanistic studies of artemisinin resistance using genomic technologies and molecular characterization of candidate resistance genes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI128940-04
Application #
9834819
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
O'Neil, Michael T
Project Start
2016-12-13
Project End
2021-11-30
Budget Start
2019-12-01
Budget End
2020-11-30
Support Year
4
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of South Florida
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
069687242
City
Tampa
State
FL
Country
United States
Zip Code
33617
Bunditvorapoom, Duangkamon; Kochakarn, Theerarat; Kotanan, Namfon et al. (2018) Fitness Loss under Amino Acid Starvation in Artemisinin-Resistant Plasmodium falciparum Isolates from Cambodia. Sci Rep 8:12622
Siddiqui, Faiza A; Cabrera, Mynthia; Wang, Meilian et al. (2018) Plasmodium falciparum Falcipain-2a Polymorphisms in Southeast Asia and Their Association With Artemisinin Resistance. J Infect Dis 218:434-442
Bai, Yao; Zhang, Jiaqi; Geng, Jinting et al. (2018) Longitudinal surveillance of drug resistance in Plasmodium falciparum isolates from the China-Myanmar border reveals persistent circulation of multidrug resistant parasites. Int J Parasitol Drugs Drug Resist 8:320-328