Molecular Surveillance and Ex Vivo Drug Susceptibilities of Plasmodium vivax Isolates From the China-Myanmar Border

• Published in: Frontiers in cellular and infection microbiology Vol. 11; p. 738075
• Main Authors: Zeng, Weilin, Zhao, Hui, Zhao, Wei, Yang, Qi, Li, Xinxin, Li, Xiaosong, Duan, Mengxi, Wang, Xun, Li, Cuiying, Xiang, Zheng, Chen, Xi, Cui, Liwang, Yang, Zhaoqing
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 01.11.2021
• Subjects: Cellular and Infection Microbiology; China–Myanmar border; drug sensitivity; multidrug resistance protein 1 gene; multidrug resistance-1 gene; Multidrug Resistance-Associated Proteins - genetics; Myanmar; Pharmaceutical Preparations; Plasmodium vivax; Plasmodium vivax - genetics; Protozoan Proteins - genetics; Myanmar; Plasmodium vivax; multidrug resistance-1 gene; China–Myanmar border; drug sensitivity; multidrug resistance protein 1 gene
• ISSN: 2235-2988; 2235-2988
• DOI: 10.3389/fcimb.2021.738075

Drug resistance in may pose a challenge to malaria elimination. Previous studies have found that has a decreased sensitivity to antimalarial drugs in some areas of the Greater Mekong Sub-region. This study aims to investigate the drug susceptibilities of . isolates from the China-Myanmar border and genetic variations of resistance-related genes. A total of 46 P. clinical isolates were assessed for susceptibility to seven antimalarial drugs using the schizont maturation assay. The medians of IC (half-maximum inhibitory concentrations) for chloroquine, artesunate, and dihydroartemisinin from 46 parasite isolates were 96.48, 1.95, and 1.63 nM, respectively, while the medians of IC values for piperaquine, pyronaridine, mefloquine, and quinine from 39 parasite isolates were 19.60, 15.53, 16.38, and 26.04 nM, respectively. Sequence polymorphisms in ( . multidrug resistance-1), ( . multidrug resistance protein 1), ( .  dihydrofolate reductase), and ( . dihydropteroate synthase) were determined by PCR and sequencing. had 13 non-synonymous substitutions, of which, T908S and T958M were fixed, G698S (97.8%) and F1076L (93.5%) were highly prevalent, and other substitutions had relatively low prevalences. had three non-synonymous substitutions, with Y1393D being fixed, G1419A approaching fixation (97.8%), and V1478I being rare (2.2%). Several and mutations were relatively frequent in the studied parasite population. The G698S substitution was associated with a reduced sensitivity to chloroquine, artesunate, and dihydroartemisinin. This study suggests the possible emergence of . isolates resistant to certain antimalarial drugs at the China-Myanmar border, which demands continuous surveillance for drug resistance.