title: Molecular analysis of chloroquine and sulfadoxine-pyrimethamine resistance-associated alleles in Plasmodium falciparum isolates from Nicaragua.
abstract: Chloroquine (CQ) is used as a first-line therapy for the treatment of Plasmodium falciparum malaria in Nicaragua. We investigated the prevalence of molecular markers associated with CQ and sulfadoxine-pyrimethamine (SP) resistance in P. falciparum isolates obtained from the North Atlantic Autonomous Region of Nicaragua. Blood spots for this study were made available from a CQ and SP drug efficacy trial conducted in 2005 and also from a surveillance study performed in 2011. Polymorphisms in P. falciparum CQ resistance transporter, dihydrofolate reductase, and dihydropteroate synthase gene loci that are associated with resistance to CQ, pyrimethamine, and sulfadoxine, respectively, were detected by DNA sequencing. In the 2005 dataset, only 2 of 53 isolates had a CQ resistance allele (CVIET), 2 of 52 had a pyrimethamine resistance allele, and 1 of 49 had a sulfadoxine resistance allele. In the 2011 dataset, none of 45 isolates analyzed had CQ or SP resistance alleles.
authors.affiliation: Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia; Atlanta Research and Education Foundation, Decatur, Georgia; National Reference and Diagnosis Center, Ministry of Health, Managua, Nicaragua; Pan American Health Organization, Managua, Nicaragua.
authors.forename: Sankar
authors.initials: S
authors.lastname: Sridaran
authors.forename: Betzabe
authors.initials: B
authors.lastname: Rodriguez
authors.forename: Aida Mercedes
authors.initials: AM
authors.lastname: Soto
authors.forename: Alexandre
authors.initials: A
authors.lastname: Macedo De Oliveira
authors.forename: Venkatachalam
authors.initials: V
authors.lastname: Udhayakumar
mesh_terms: D000483:Alleles; D000962:Antimalarials / Q000494:pharmacology; D002738:Chloroquine / Q000494:pharmacology*; D016054:DNA, Protozoan / Q000235:genetics; D004094:Dihydropteroate Synthase / Q000235:genetics; D004338:Drug Combinations; D004351:Drug Resistance / Q000235:genetics*; D006801:Humans; D016778:Malaria, Falciparum / Q000188:drug therapy; D026901:Membrane Transport Proteins / Q000235:genetics; D009527:Nicaragua; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D011110:Polymorphism, Genetic; D011739:Pyrimethamine / Q000494:pharmacology*; D017422:Sequence Analysis, DNA; D013413:Sulfadoxine / Q000494:pharmacology*; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics
chemical_list: D000962:Antimalarials; D016054:DNA, Protozoan; D004338:Drug Combinations; D026901:Membrane Transport Proteins; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D002738:Chloroquine; D013762:Tetrahydrofolate Dehydrogenase; D004094:Dihydropteroate Synthase; D011739:Pyrimethamine