title: Genetic diversity of polymorphic vaccine candidate antigens (apical membrane antigen-1, merozoite surface protein-3, and erythrocyte binding antigen-175) in Plasmodium falciparum isolates from western and central Africa.
abstract: The malaria vaccine candidate antigens erythrocyte binding antigen 175 (EBA-175), merozoite surface protein 3 (MSP-3), and apical membrane antigen (AMA-1) from Plasmodium falciparum isolates from countries in central and west Africa were assessed for allelic diversity. Samples were collected on filter paper from 600 P. falciparum-infected symptomatic patients in Cameroon, Republic of Congo, Burkina Faso, Ghana, and Senegal and screened for class-specific amplification fragments. Genetic diversity, assessed by mean heterozygosity, was comparable among countries. We detected a clinical increase in eba 175 F-allele frequency from west to east across the study region. No statistical difference in msp-3 allele distribution between countries was observed. The ama-1 3D7 alleles were present at a lower frequency in central Africa than in West Africa. We also detected little to no genetic differentiation among sampling locations. This finding indicates that, at least at the level of resolution offered by restriction fragment length polymorphism analysis, these antigens showed remarkable genetic homogeneity throughout the region sampled, perhaps caused by balancing selection to maintain a diverse array of antigen haplotyes.
authors.affiliation: Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso. a.soulama.cnrfp@fasonet.bf
authors.forename: Issiaka
authors.initials: I
authors.lastname: Soulama
authors.forename: Jude D
authors.initials: JD
authors.lastname: Bigoga
authors.forename: Magatte
authors.initials: M
authors.lastname: Ndiaye
authors.forename: Edith C
authors.initials: EC
authors.lastname: Bougouma
authors.forename: Josephine
authors.initials: J
authors.lastname: Quagraine
authors.forename: Prisca N
authors.initials: PN
authors.lastname: Casimiro
authors.forename: Timothy T
authors.initials: TT
authors.lastname: Stedman
authors.forename: Sodiomon B
authors.initials: SB
authors.lastname: Sirima
mesh_terms: D000350:Africa, Central; D000354:Africa, Western; D000483:Alleles; D000953:Antigens, Protozoan / Q000235:genetics* / Q000276:immunology; D016054:DNA, Protozoan / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D017780:Malaria Vaccines / Q000235:genetics*; D016778:Malaria, Falciparum / Q000235:genetics / Q000469:parasitology / Q000517:prevention & control; D010963:Plasmodium falciparum / Q000235:genetics* / Q000276:immunology; D016133:Polymerase Chain Reaction; D015800:Protozoan Proteins / Q000235:genetics* / Q000276:immunology
chemical_list: D000953:Antigens, Protozoan; D016054:DNA, Protozoan; D017780:Malaria Vaccines; D015800:Protozoan Proteins; C085731:erythrocyte membrane protein 1, Plasmodium falciparum; C065668:erythrocyte-binding antigen 175, Plasmodium; C089133:merozoite surface protein 3, Plasmodium