title: Evaluation of Toxoplasma ELITe MGB Real-Time PCR Assay for Diagnosis of Toxoplasmosis.
abstract: Molecular diagnosis of congenital toxoplasmosis or disseminated toxoplasmosis is based mainly on PCR. The repeated DNA elementrep529has become the main DNA target used in most PCR methods, whether laboratory developed or commercial. In this multicenter study, we evaluated theToxoplasmaELITe MGB (Elitech) commercial kit by comparison with three reference quantitative PCR assays (RAs) used routinely in three proficient laboratories of the French National Reference Center for Toxoplasmosis network, usingToxoplasmacalibrated suspensions diluted to obtain a range of concentrations from 0.1 to 10,000 parasites/ml. These suspensions were extracted with either the DNA extraction kit (EXTRAblood; Elitech) recommended by the manufacturer or the QIAamp DNA minikit (Qiagen). TheToxoplasmaELITe MGB assay was also evaluated on a panel of 128 clinical samples, including 56 amniotic fluid samples, 55 placenta samples, and various other samples, of which 95 originated from patients with proven toxoplasmosis. The ELITe MGB assay amplified low-concentration replicates (<10 parasites/ml) of calibrated suspensions less frequently than the RAs of 2/3 laboratories. Additionally, the combination of EXTRAblood andToxoplasmaELITe MGB yielded poorer sensitivity than the combination of QIAamp DNA minikit and ELITe MGB for low parasite concentrations (P< 0.001 for 1 parasite/ml). On clinical samples, the sensitivity and the specificity of the commercial assay were 89% and 100%, respectively. The sensitivity ranged from 79% (placenta samples) to 100% (amniotic fluid samples). Overall, this study shows that theToxoplasmaELITe MGB assay is suitable for the diagnosis of toxoplasmosis from non-cell-rich or non-hemoglobin-rich samples and that the EXTRAblood kit is not optimal.
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Rennes, Rennes, France florence.robert-gangneux@univ-rennes1.fr.|IRSET, INSERM U1085, Université Rennes 1, Rennes, France.|Centre National de Référence de la Toxoplasmose, Pôle Biologie Moléculaire, Montpellier, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Robert-Gangneux
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Institut de Biologie et Pathologie, Centre Hospitalier Universitaire de Grenoble, Grenoble, France.|Institute for Advanced Biosciences, INSERM U1209-CNRS UMR 5309, Université Grenoble Alpes, Grenoble, France.|Centre National de Référence de la Toxoplasmose, Pôle Biologie Moléculaire, Montpellier, France.
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Brenier-Pinchart
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Hôpital Cochin, Hôpitaux Universitaires Paris Centre, AP-HP, Faculté de Médecine, Université Paris Descartes, Paris, France.|Centre National de Référence de la Toxoplasmose, Pôle Biologie Moléculaire, Montpellier, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Yera
authors.affiliation: Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Rennes, Rennes, France.|IRSET, INSERM U1085, Université Rennes 1, Rennes, France.
authors.forename: Sorya
authors.initials: S
authors.lastname: Belaz
authors.affiliation: Département de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Montpellier, and UMR CNRS 5290-IRD 224, Université de Montpellier, Montpellier, France.|Centre National de Référence de la Toxoplasmose, Pôle Biologie Moléculaire, Montpellier, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Varlet-Marie
authors.affiliation: Département de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Montpellier, and UMR CNRS 5290-IRD 224, Université de Montpellier, Montpellier, France.|Centre National de Référence de la Toxoplasmose, Pôle Biologie Moléculaire, Montpellier, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Bastien
mesh_terms: D000653:Amniotic Fluid / Q000469:parasitology; D016054:DNA, Protozoan / Q000235:genetics*; D005260:Female; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D010920:Placenta / Q000469:parasitology; D011247:Pregnancy; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014122:Toxoplasma / Q000235:genetics* / Q000302:isolation & purification; D014125:Toxoplasmosis, Congenital / Q000175:diagnosis* / Q000469:parasitology
chemical_list: D016054:DNA, Protozoan
keywords: PCR; Toxoplasma gondii; diagnosis; rep529; toxoplasmosis