Different allele prevalence in the dihydrofolate reductase and dihydropteroate synthase genes in Plasmodium vivax populations from China.
Antifolate resistance in Plasmodium vivax is caused by point mutations in genes encoding dihydrofolate reductase (pvdhfr) and dihydropteroate synthase (pvdhps). In this study, we used direct sequencing to survey pvdhfr and pvdhps mutations in 122 clinical P. vivax isolates from a central and a southern province of China. For pvdhfr, 36.9% were wild-type, whereas mutations were detected at four codons (57, 58, 61, and 117). The S117N/T mutation was the most prevalent (48.4%), followed by the T61M mutation (18.9%). Six pvdhfr mutant alleles were found, ranging from 37.7% to 0.8%. The dramatically different pvdhfr allele frequencies between the two P. vivax populations might be caused by different drug histories or intrinsic difference between temperate and subtropical strains. In contrast, except polymorphisms within a repeat region, no resistance-conferring mutations were detected in pvdhps. Our result suggests that P. vivax populations in China may be relatively susceptible to sulfadoxine-pyrimethamine.
Department of Entomology, Pennsylvania State University, University Park, Pennsylvania 16802, USA. doublemiao@gmail.com
Miao
M
Miao
Zhaoqing
Z
Yang
Long
L
Cui
Jessica
J
Ahlum
Yaming
Y
Huang
Liwang
L
Cui
D000483:Alleles; D000595:Amino Acid Sequence; D000962:Antimalarials / Q000494:pharmacology; D002681:China / Q000453:epidemiology; D016054:DNA, Protozoan; D004094:Dihydropteroate Synthase / Q000235:genetics* / Q000378:metabolism; D004338:Drug Combinations; D004351:Drug Resistance / Q000235:genetics; D005838:Genotype; D006801:Humans; D016780:Malaria, Vivax / Q000453:epidemiology* / Q000469:parasitology; D008969:Molecular Sequence Data; D010966:Plasmodium vivax / Q000201:enzymology* / Q000235:genetics*; D017354:Point Mutation; D011110:Polymorphism, Genetic; D011739:Pyrimethamine / Q000494:pharmacology; D013413:Sulfadoxine / Q000494:pharmacology; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics* / Q000378:metabolism
D000962:Antimalarials; D016054:DNA, Protozoan; D004338:Drug Combinations; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D013762:Tetrahydrofolate Dehydrogenase; D004094:Dihydropteroate Synthase; D011739:Pyrimethamine