No abstract

To study the influence of Toxoplasma gondii genotypes on the severity of human congenital toxoplasmosis (asymptomatic, benign, or severe infection or newborn or fetal death), 8 microsatellite markers were used to analyze 86 T. gondii isolates collected from patients with congenital toxoplasmosis. Seventy-four different genotypes were detected, some identical genotypes originating probably from the same source of contamination. The 3 less polymorphic microsatellite markers associated with 6 isoenzymatic markers allowed a classification of isolates into the 3 classical types and detected atypical genotypes. Whatever the clinical findings, type II isolates were largely predominant (84.88% in the whole collection and 96.49% in 57 consecutive cases). Type I and atypical isolates were not found in asymptomatic or benign congenital toxoplasmosis. However, in 4 cases in which children were not infected despite isolation of T. gondii from placenta, only type I isolates were found.

No abstract

For the prenatal diagnosis of congenital T. gondii infection, an approach based on a PCR test performed on amniotic fluid is rapid, safe, and accurate.

We report the genotyping analysis of Toxoplasma gondii isolates in samples collected from 88 immunocompromised patients, along with clinical and epidemiological data. Most of these samples were collected in France during the current decade by the Toxoplasma Biological Resource Center. Lack of specific anti-Toxoplasma treatment, pulmonary toxoplasmosis, and involvement of multiple organs were the 3 main risk factors associated with death for this patient group. Genotyping results with 6 microsatellite markers showed that type II isolates were predominant among patients who acquired toxoplasmic infection in Europe. Non-type II isolates included 13 different genotypes and were mainly collected from patients who acquired toxoplasmosis outside Europe. Type III was the second most common genotype recovered from patients, whereas type I was rare in our population. Three nonarchetypal genotypes were repeatedly recovered from different patients who acquired the infection in sub-Saharan Africa (genotypes Africa 1 and Africa 2) and in the French West Indies (genotype Caribbean 1). The distribution of genotypes (type II vs. non-type II) was not significantly different when patients were stratified by underlying cause of immunosuppression, site of infection, or outcome. We conclude that in immunocompromised patients, host factors are much more involved than parasite factors in patients' resistance or susceptibility to toxoplasmosis.