Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
ISSN: 0066-4804

pasteur-00590987
https://hal-riip.archives-ouvertes.fr/pasteur-00590987
DOI : 10.1128/AAC.01532-06
PUBMED : 17438062

Éditeur(s) : HAL CCSD Centers for Disease Control and Prevention
Résumé : International audience
From 1998 through 2006, 44 cases of severe primary toxoplasmosis were observed in French Guiana in immunocompetent adults. Toxoplasma gondii isolates exhibited an atypical multilocus genotype. Severe disease in humans may result from poor host adaptation to neotropical zoonotic strains of T. gondii circulating in a forest-based cycle.
ISSN: 1080-6040

hal-00406549
https://hal.archives-ouvertes.fr/hal-00406549
PUBMED : 19331765

Éditeur(s) : HAL CCSD Elsevier
Résumé : Field isolates of Toxoplasma gondii in Europe and North America have been grouped into three clonal lineages that display different virulence in mice. Whether the genetic structure of the parasite is related to clinical expression in humans has not yet been demonstrated. We developed an enzyme-linked immunosorbent assay which uses lineage-specific, polymorphic polypeptides derived from the dense granule antigens, GRA5 and GRA6. Our goal was to compare serotypical patterns observed in asymptomatic versus symptomatic (ocular disease and severe infection in human immunodeficiency virus (HIV)-positive patients) infections among patients from Europe and South America. Independent of the clinical presentation of the disease, serotypes differed according to geographical origin, with a homogeneous distribution of serotype II in Europe and of serotypes I and III in South America. We conclude that GRA5-GRA6 serotyping is an interesting tool to study serotype prevalence in populations but it is not an accurate marker of pathogenicity of Toxoplasma infection in humans.
ISSN: 1286-4579

hal-00306841
https://hal.archives-ouvertes.fr/hal-00306841
DOI : 10.1016/j.micinf.2008.04.001
PUBMED : 18539501

Éditeur(s) : HAL CCSD
Résumé : International audience
Some of the immunologic mechanisms involved in malaria physiopathology remain unclear. In animals, the spleen seems to play a key role in protecting the host against malaria. However, little is known about the effect of spleen dysfunction on human malaria. We report two severe cases of Plasmodium falciparum infection with unusual clinical and parasitologic features in two splenectomized men living in French Guiana. The peripheral blood of these cases showed hyperparasitemia, with a high proportion of mature parasites and leukocytes with malaria pigment. Despite appropriate treatment and adequate absorption, hyperparasitemia persisted. Parasite clearance was delayed and one patient died. Only the patient who died had the merozoite surface protein 1 allele B-K1 and the varD gene genotype, which is considered to be a probable parasite virulence factor. These uncommon cases differ from most of those described in the literature, illustrating the complexity of the mechanisms underlying the protective function of the spleen in human malaria.
The American journal of tropical medicine and hygiene

pasteur-00590993
https://hal-riip.archives-ouvertes.fr/pasteur-00590993
PUBMED : 15381808