Direct evidence that asparagine at position 108 of the Plasmodium falciparum dihydrofolate reductase is involved in resistance to antifolate drugs in Tanzania.
A nested polymerase chain reaction was used to amplify a fragment of the gene for dihydrofolate reductase of Plasmodium falciparum containing codon 108, where a point mutation, causing a serine to asparagine change, occurs in pyrimethamine resistant parasites. The presence of the mutation was detected by restriction enzyme digestion. Parasites in blood samples collected from asymptomatic children before, and 3 weeks after, treatment with pyrimethamine-sulfadoxine or chlorproguanil-dapsone were analysed. Parasites in the samples taken at 3 weeks carried only the asparagine mutant.
Curtis
J
J
London School of Hygiene and Tropical Medicine, UK.
Duraisingh
M T
MT
Trigg
J K
JK
Mbwana
H
H
Warhurst
D C
DC
Curtis
C F
CF
D000818:Animals; D002648:Child; D002675:Child, Preschool; D004351:Drug Resistance / Q000235:genetics; D005493:Folic Acid Antagonists / Q000627:therapeutic use*; D006801:Humans; D007223:Infant; D010963:Plasmodium falciparum / Q000235:genetics*; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*
D005493:Folic Acid Antagonists; D013762:Tetrahydrofolate Dehydrogenase