title: Molecular assessment of Plasmodium falciparum resistance to antimalarial drugs in Papua New Guinea using an extended ligase detection reaction fluorescent microsphere assay.
abstract: Surveillance for Plasmodium falciparum drug resistance mutations is becoming an established tool for assessing antimalarial treatment effectiveness. We used an extended version of a high-throughput post-PCR multiplexed ligase detection reaction fluorescent microsphere assay (LDR-FMA) to detect single-nucleotide P. falciparum drug resistance polymorphisms in 402 isolates from children in Papua New Guinea (PNG) participating in an antimalarial treatment trial. There was a fixation of P. falciparum crt (pfcrt) K76T, pfdhfr C59R and S108N, and pfmdr1 mutations (92%, 93%, 95%, and 91%, respectively). Multiple mutations were frequent. Eighty-eight percent of isolates possessed a quintuple mutation (underlined), SVMNT, NRNI, KAA, and YYSND, in codons 72 to 76 for pfcrt; 51, 59, 108, and 164 for pfdhfr; 540, 581, and 613 for pfdhps; and 86, 184, 1034, 1042, and 1246 for pfmdr1, and four of these carried the K540E pfdhps allele. The pfmdr1 D1246Y mutation was associated with PCR-corrected day 42 in vivo treatment failure in children allocated piperaquine-dihydroartemisinin (P = 0.004). Although the pfmdr1 NFSDD haplotype was found in only four isolates, it has been associated with artemether-lumefantrine treatment failure in Africa. LDR-FMA allows the large-scale assessment of resistance-associated single-nucleotide polymorphisms (SNPs). Our findings reflect previous heavy 4-aminoquinoline/sulfadoxine-pyrimethamine use in PNG. Since artemether-lumefantrine and piperaquine-dihydroartemisinin will become first- and second-line treatments, respectively, the monitoring of pfmdr1 SNPs appears to be a high priority.
authors.affiliation: School of Medicine and Pharmacology, Fremantle Unit, University of Western Australia, Nedlands, Western Australia, Australia.
authors.forename: Rina P M
authors.initials: RP
authors.lastname: Wong
authors.forename: Harin
authors.initials: H
authors.lastname: Karunajeewa
authors.forename: Ivo
authors.initials: I
authors.lastname: Mueller
authors.forename: Peter
authors.initials: P
authors.lastname: Siba
authors.forename: Peter A
authors.initials: PA
authors.lastname: Zimmerman
authors.forename: Timothy M E
authors.initials: TM
authors.lastname: Davis
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D002675:Child, Preschool; D004351:Drug Resistance / Q000235:genetics*; D005453:Fluorescence; D006801:Humans; D007223:Infant; D008025:Ligases / Q000378:metabolism; D016778:Malaria, Falciparum / Q000469:parasitology; D008863:Microspheres; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics; D010219:Papua New Guinea; D021261:Parasitic Sensitivity Tests; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D015800:Protozoan Proteins / Q000235:genetics*
chemical_list: D000962:Antimalarials; D008025:Ligases; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D015800:Protozoan Proteins; C513498:Mdr1 protein, Plasmodium falciparum