Microsatellite characterization of Plasmodium falciparum from symptomatic and non-symptomatic infections from the Western Amazon reveals the existence of non-symptomatic infection-associated genotypes.
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.
dalla Martha
Rosimeire Cristina
RC
Centro de Pesquisa em Medicina Tropical, Porto Velho, RO, Brasil.
Tada
Mauro Sughiro
MS
Ferreira
Ricardo Godoi de Mattos
RG
da Silva
Luiz Hildebrando Pereira
LH
Wunderlich
Gerhard
G
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
D016054:DNA, Protozoan; D005819:Genetic Markers