Real-time PCR for dihydrofolate reductase gene single-nucleotide polymorphisms in Plasmodium vivax isolates.
Mutations in the dhfr gene of Plasmodium vivax (pvdhfr) are associated with resistance to the antifolate antimalarial drugs. Polymorphisms in the pvdhfr gene were assessed by hybridization probe technology on the LightCycler instrument with 134 P. vivax-infected blood samples from Turkey (n = 24), Azerbaijan (n = 39), Thailand (n = 16), Indonesia (n = 53), and travelers (n = 19). Double mutations (S58R and S117N) or quadruple mutations (F57L/I, S58R, T61M, and S117N) in the pvdhfr genes were found in all Thai samples (100%). pvdhfr mutant-type alleles were significantly more common in samples from travelers (42%) than in those from patients from Indonesia (5%). Surprisingly, the pvdhfr single-mutation allele (S117N) was identified at a high frequency in parasites from Turkey and Azerbaijan (71 and 36%, respectively), where sulfadoxine-pyrimethamine is not recommended for the treatment of P. vivax malaria by the World Health Organization and the Malaria National Programs.
Brega
Sara
S
Service de Parasitologie, Faculté de Médecine, 8 avenue Rockefeller, 69373 Lyon cedex 08, France.
de Monbrison
Frédérique
F
Severini
Carlo
C
Udomsangpetch
Rachanee
R
Sutanto
Inge
I
Ruckert
Paul
P
Peyron
François
F
Picot
Stéphane
S
D000328:Adult; D000595:Amino Acid Sequence; D000818:Animals; D016054:DNA, Protozoan / Q000235:genetics; D006801:Humans; D016780:Malaria, Vivax / Q000469:parasitology; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D010966:Plasmodium vivax / Q000201:enzymology* / Q000235:genetics*; D017354:Point Mutation / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*
D016054:DNA, Protozoan; D015345:Oligonucleotide Probes; D013762:Tetrahydrofolate Dehydrogenase