Direct Genotyping of Toxoplasma gondii in Ocular Fluid Samples from 20 Patients with Ocular Toxoplasmosis: Predominance of Type II in France

Fekkar, Arnaud; Ajzenberg, Daniel; Bodaghi, Bahram; Touafek, Fériel; Hoang, P. Le; Delmas, J.; Robert, P.-Y.; Dardé, Marie‐Laure; Mazier, Dominique; Paris, Luc

doi:10.1128/jcm.02196-10

Cited by 63 publications

(42 citation statements)

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“…All 67 T. gondii strains isolated from different areas of Austria were genotype II (ToxoDB #1or #3), suggesting the clonal population structure. These results was similar with previous findings reporting the predominance of T. gondii type II in cats in bordered countries, Germany and France (Herrmann et al 2010;Fekkar et al 2011;Maksimov et al 2013). MS analysis of 67 type II isolates from Austria consisted of only 13 different genotypes.…”

Section: Discussionsupporting

confidence: 94%

Genetic characterization ofToxoplasma gondiiisolates from Portugal, Austria and Israel reveals higher genetic variability within the type II lineage

et al. 2015

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This study compared genetic diversity of Toxoplasma gondii isolates from Portugal, Austria and Israel. For this, we genotyped 90 T. gondii isolates (16 from Portugal, 67 from Austria and 7 from Israel) using 10 nested PCR-restriction length polymorphism (RFLP) genetic markers and 15 microsatellite (MS) markers. By PCR-RFLP typing, 7 isolates from Portugal chickens were identified as type II (ToxoDB #1 or #3), 4 were type III (ToxoDB #2) and the remaining 4 isolates have unique genotype pattern were designated as ToxoDB #254. One mouse virulent isolate from a bovine fetus (Bos taurus) in Portugal was type I (ToxoDB #10) at all loci and designated as TgCowPr1. All 67 isolates from Austria and 7 from Israel were type II (ToxoDB #1 or #3). By MS typing, many additional genetic variations were revealed among the type II and type III isolates. Phylogenetic analysis showed that isolates from the same geographical locations tend to cluster together, and there is little overlapping of genotypes among different locations. This study demonstrated that the MS markers can provide higher discriminatory power to reveal association of genotypes with geographical locations. Future studies of the type II strains in Europe by these MS markers will be useful to reveal transmission patterns of the parasite.

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Section: Discussionsupporting

confidence: 94%

Genetic characterization ofToxoplasma gondiiisolates from Portugal, Austria and Israel reveals higher genetic variability within the type II lineage

et al. 2015

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“…Toxoplasma gondii strains have different capacities of dissemination according to their genetic background (16), which may explain why the sensitivity of PCR with peripheral blood was lower here than in studies performed in Brazil (20)(21)(22). In France, genotype II is most frequently responsible for OT (23); additional studies in other geographical zones should be performed to assess locally the performance of blood PCR in OT.…”

Section: Discussionmentioning

confidence: 83%

PCR-Based Detection of Toxoplasma gondii DNA in Blood and Ocular Samples for Diagnosis of Ocular Toxoplasmosis

et al. 2014

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dPCR detection of Toxoplasma gondii in blood has been suggested as a possibly efficient method for the diagnosis of ocular toxoplasmosis (OT) and furthermore for genotyping the strain involved in the disease. To assess this hypothesis, we performed PCR with 121 peripheral blood samples from 104 patients showing clinical and/or biological evidence of ocular toxoplasmosis and from 284 (258 patients) controls. We tested 2 different extraction protocols, using either 200 l (small volume) or 2 ml (large volume) of whole blood. Sensitivity was poor, i.e., 4.1% and 25% for the small-and large-volume extractions, respectively. In comparison, PCR with ocular samples yielded 35.9% sensitivity, while immunoblotting and calculation of the Goldmann-Witmer coefficient yielded 47.6% and 72.3% sensitivities, respectively. Performing these three methods together provided 89.4% sensitivity. Whatever the origin of the sample (ocular or blood), PCR provided higher sensitivity for immunocompromised patients than for their immunocompetent counterparts. Consequently, PCR detection of Toxoplasma gondii in blood samples cannot currently be considered a sufficient tool for the diagnosis of OT, and ocular sampling remains necessary for the biological diagnosis of OT.

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“…Strains isolated from patients are mainly the strains circulating in a given country, and the same type of strain can be responsible for different outcomes. For example, type II strains were involved in 96% of consecutive cases of congenital toxoplasmosis in France (9), in 85% of immunocompromised patients who acquired Toxoplasma infection in Europe (12), and in 73% of cases of ocular disease in France (121). In immunocompromised patients, the conclusion of a study of 85 patients (HIV and non-HIV immunodeficient patients) was that the genotype of the infecting strain had no influence on the clinical manifestation (cerebral or extracerebral) or clinical outcome (12), indicating that immune status is responsible for virulence expression in these patients.…”

Section: Genotypes and Virulencementioning

confidence: 99%

Epidemiology of and Diagnostic Strategies for Toxoplasmosis

2012

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SUMMARY The apicomplexan parasite Toxoplasma gondii was discovered a little over 100 years ago, but knowledge of its biological life cycle and its medical importance has grown in the last 40 years. This obligate intracellular parasite was identified early as a pathogen responsible for congenital infection, but its clinical expression and the importance of reactivations of infections in immunocompromised patients were recognized later, in the era of organ transplantation and HIV infection. Recent knowledge of host cell-parasite interactions and of parasite virulence has brought new insights into the comprehension of the pathophysiology of infection. In this review, we focus on epidemiological and diagnostic aspects, putting them in perspective with current knowledge of parasite genotypes. In particular, we provide critical information on diagnostic methods according to the patient's background and discuss the implementation of screening tools for congenital toxoplasmosis according to health policies.

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Direct Genotyping of Toxoplasma gondii in Ocular Fluid Samples from 20 Patients with Ocular Toxoplasmosis: Predominance of Type II in France

Cited by 63 publications

References 31 publications

Genetic characterization ofToxoplasma gondiiisolates from Portugal, Austria and Israel reveals higher genetic variability within the type II lineage

Genetic characterization ofToxoplasma gondiiisolates from Portugal, Austria and Israel reveals higher genetic variability within the type II lineage

PCR-Based Detection of Toxoplasma gondii DNA in Blood and Ocular Samples for Diagnosis of Ocular Toxoplasmosis

Epidemiology of and Diagnostic Strategies for Toxoplasmosis

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