title: Microsatellite characterization of Plasmodium falciparum from symptomatic and non-symptomatic infections from the Western Amazon reveals the existence of non-symptomatic infection-associated genotypes.
abstract: In Western Amazon areas with perennial malaria transmission, long term residents frequently develop partial immunity to malarial infection caused either by Plasmodium falciparum or P. vivax, resulting in a considerable number of non-symptomatically infected individuals. For yet unknown reasons, these individuals sporadically develop symptomatic malaria. In order to identify if determined parasite genotypes, defined by a combination of eleven microsatellite markers, were associated to different outcomes--symptomatic or asymptomatic malaria--we analyzed infecting P. falciparum parasites in a suburban riverine population. Despite of detecting a high degree of diversity in the analyzed samples, several microsatellite marker alleles appeared accumulated in parasites from non-symptomatic infections. This result may be interpreted that a number of microsatellites, which are not directly related to antigenic features, could be associated to the outcome of malarial infection. The result may also point to a low frequency of recombinatorial events which otherwise would dissociate genes under strong immune pressure from the relatively neutral microsatellite loci.
authors.affiliation: Centro de Pesquisa em Medicina Tropical, Porto Velho, RO, Brasil.
authors.forename: Rosimeire Cristina
authors.initials: RC
authors.lastname: dalla Martha
authors.forename: Mauro Sughiro
authors.initials: MS
authors.lastname: Tada
authors.forename: Ricardo Godoi de Mattos
authors.initials: RG
authors.lastname: Ferreira
authors.forename: Luiz Hildebrando Pereira
authors.initials: LH
authors.lastname: da Silva
authors.forename: Gerhard
authors.initials: G
authors.lastname: Wunderlich
mesh_terms: D000483:Alleles; D000818:Animals; D001938:Brazil; D016054:DNA, Protozoan / Q000235:genetics*; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D016778:Malaria, Falciparum / Q000469:parasitology*; D018895:Microsatellite Repeats / Q000235:genetics*; D010963:Plasmodium falciparum / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012307:Risk Factors
chemical_list: D016054:DNA, Protozoan; D005819:Genetic Markers