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Fadel EF, EL-Hady HA, Ahmed AM, Tolba MEM. Molecular diagnosis of human toxoplasmosis: the state of the art. J Parasit Dis 2024; 48:201-216. [PMID: 38840888 PMCID: PMC11147977 DOI: 10.1007/s12639-024-01667-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 03/23/2024] [Indexed: 06/07/2024] Open
Abstract
Toxoplasma gondii (T. gondii) is an obligate intracellular apicomplexan protozoan that causes toxoplasmosis. Approximately one-third of the world's population is currently T. gondii-seropositive. Although most infections are symptomless, a few can produce retinal lesions and, in immunocompromised persons or when congenitally contracted, can progress to life-threatening central nervous system disseminated infections. Therefore, quick, and precise diagnosis is a must. Molecular techniques nowadays play a crucial role in toxoplasmosis diagnosis, particularly in immunocompromised patients or congenital toxoplasmosis. This review aimed to detail recent advancements in molecular diagnostics of T. gondii infections. The terms "Toxoplasmosis," "Molecular diagnostics," "PCR," "qPCR," "B1," and "rep529" were used to search the English-language literature. In developed nations, conventional PCR (PCR) and nested PCR have been supplanted by quantitative PCR (qPCR), although they are still widely employed in poor nations. The diagnosis of toxoplasmosis has been revolutionized by the emergence of molecular diagnostics. Unfortunately, there is still substantial interlaboratory variability. There is an immediate need for standardization to increase the comparability of results between laboratories and clinical trials. Graphical abstract A graphical abstract highlighting the summary of Toxoplasma molecular diagnostics, created using Biorender.com.
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Affiliation(s)
- Eman Fathi Fadel
- Department of Medical Parasitology, Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Hanaa Ahmed EL-Hady
- Department of Medical Parasitology, Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Amal Mostafa Ahmed
- Department of Medical Parasitology, Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Mohammed Essa Marghany Tolba
- Department of Microbiology and Clinical Parasitology, Faculty of Medicine, King Khaled University, Abha, Saudi Arabia
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Robert MG, Brenier-Pinchart MP, Garnaud C, Fricker-Hidalgo H, Pelloux H. Molecular diagnosis of toxoplasmosis: recent advances and a look to the future. Expert Rev Anti Infect Ther 2021; 19:1529-1542. [PMID: 34112045 DOI: 10.1080/14787210.2021.1941867] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Toxoplasmosis is a globally distributed parasitic infection that can be particularly severe when opportunistic or congenital. Its diagnosis requires accurate and rapid techniques that rely mainly on serology and molecular methods. AREAS COVERED The aim of this review was to discuss the positioning of the molecular diagnosis of toxoplasmosis according to the different clinical situations possibly resulting from infection with T. gondii, and to detail recent developments in this technique. The English and French literature were searched with the following keywords: 'Toxoplasmosis', "Molecular diagnosis" and 'PCR'. EXPERT OPINION Molecular techniques have revolutionized the diagnosis of toxoplasmosis, and practices have considerably evolved over the past decades. However, there is still a high degree of inter-laboratory heterogeneity which impairs comparisons between results and studies. Efforts to standardize practices are underway.
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Affiliation(s)
- Marie Gladys Robert
- Service de Parasitologie-Mycologie, CHU Grenoble Alpes, Grenoble, France.,Université Grenoble Alpes, Institut pour l'Avancée des Biosciences (IAB), Grenoble, France
| | - Marie-Pierre Brenier-Pinchart
- Service de Parasitologie-Mycologie, CHU Grenoble Alpes, Grenoble, France.,Université Grenoble Alpes, Institut pour l'Avancée des Biosciences (IAB), Grenoble, France.,Centre National de Référence Toxoplasmose - Pôle Biologie Moléculaire, France
| | - Cécile Garnaud
- Service de Parasitologie-Mycologie, CHU Grenoble Alpes, Grenoble, France.,Université Grenoble Alpes, CNRS, CHU Grenoble Alpes, Grenoble INP, TIMC-IMAG, Grenoble, France
| | | | - Hervé Pelloux
- Service de Parasitologie-Mycologie, CHU Grenoble Alpes, Grenoble, France.,Université Grenoble Alpes, Institut pour l'Avancée des Biosciences (IAB), Grenoble, France.,Centre National de Référence Toxoplasmose - Pôle Biologie Moléculaire, France
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Brenier-Pinchart MP, Varlet-Marie E, Robert-Gangneux F, Filisetti D, Guitard J, Sterkers Y, Yera H, Pelloux H, Bastien P. Impact of pre-analytic step duration on molecular diagnosis of toxoplasmosis for five types of biological samples. PLoS One 2021; 16:e0246802. [PMID: 33596222 PMCID: PMC7888589 DOI: 10.1371/journal.pone.0246802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/26/2021] [Indexed: 11/18/2022] Open
Abstract
Introduction Toxoplasma-PCR is essential to diagnose ocular, cerebral, disseminated and congenital toxoplasmosis. This multicenter study evaluated the impact of sample storage duration at +4°C on PCR assay performances in order to propose guidelines for the storage of samples during shipment or/and before PCR. Materials and methods Five matrices, amniotic (AF), cerebrospinal (CSF), and bronchoalveolar lavage fluids (BALF), whole blood (WB) and buffy coat (BC), were artificially spiked with different amounts of Toxoplasma gondii (20, 100, 500 tachyzoites per mL of sample) or with previously infected THP1 cells. DNA extractions were performed at day 0 and after 2, 4 and 7 days of storage at +4°C. Each extract was amplified at least twice by real-time PCR. Results A total of 252 spiked samples was studied. No increase of crossing point was observed and all samples were positive for AF, BALF, BC and infected THP1-spiked WB after up to 7 days at 4°C. For CSF spiked with 20 parasites/mL, only 50% of PCR reactions were positive at D7 (p<0.05). For WB spiked with type II parasites, all reactions remained positive at D7 but amplifications were significantly delayed from D2; and for WB spiked with RH strain, the proportion of positive reactions decreased at D7. Conclusion The storage of clinical samples at +4°C is compatible with the molecular detection of T. gondii parasites. Provided that PCR assays are performed in duplicate, storage of samples is possible up to 7 days. However, from the fifth day onwards, and for samples susceptible to contain low parasitic loads, we recommend to perform the PCR in multiplicate.
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Affiliation(s)
- Marie-Pierre Brenier-Pinchart
- Laboratoire de Parasitologie-Mycologie, CHU Grenoble Alpes et Institut pour l’Avancée des Biosciences (IAB), INSERM U1209-CNRS UMR 5309, Université Grenoble Alpes Grenoble, Grenoble, France
- Centre National de Référence Toxoplasmose-Pôle Biologie Moléculaire, France
- * E-mail:
| | - Emmanuelle Varlet-Marie
- Centre National de Référence Toxoplasmose-Pôle Biologie Moléculaire, France
- Université de Montpellier et Laboratoire de Parasitologie-Mycologie CHU Montpellier, Montpellier, France
| | - Florence Robert-Gangneux
- Centre National de Référence Toxoplasmose-Pôle Biologie Moléculaire, France
- CHU Rennes, Inserm, EHESP, Irset (Institut de Recherche en Santé Environnement Travail), UMR_S 1085, Université de Rennes, Rennes, France
| | - Denis Filisetti
- Centre National de Référence Toxoplasmose-Pôle Biologie Moléculaire, France
- Institut de Parasitologie et de Pathologie Tropicale, Université de Strasbourg et Laboratoire de Parasitologie et Mycologie Médicale, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Juliette Guitard
- Centre National de Référence Toxoplasmose-Pôle Biologie Moléculaire, France
- Inserm, Centre de Recherche Saint-Antoine, CRSA, AP-HP, Hôpital Saint-Antoine, Sorbonne Université, Paris, France
| | - Yvon Sterkers
- Centre National de Référence Toxoplasmose-Pôle Biologie Moléculaire, France
- CNRS, IRD, CHU de Montpellier, "MiVEGEC" et Laboratoire de Parasitologie-Mycologie, Université de Montpellier, Montpellier, France
| | - Hélène Yera
- Centre National de Référence Toxoplasmose-Pôle Biologie Moléculaire, France
- Laboratoire de Parasitologie-Mycologie, Hôpital Cochin, Université de Paris, AP-HP, Paris, France
| | - Hervé Pelloux
- Laboratoire de Parasitologie-Mycologie, CHU Grenoble Alpes et Institut pour l’Avancée des Biosciences (IAB), INSERM U1209-CNRS UMR 5309, Université Grenoble Alpes Grenoble, Grenoble, France
- Centre National de Référence Toxoplasmose-Pôle Biologie Moléculaire, France
| | - Patrick Bastien
- Centre National de Référence Toxoplasmose-Pôle Biologie Moléculaire, France
- CNRS, IRD, CHU de Montpellier, "MiVEGEC" et Laboratoire de Parasitologie-Mycologie, Université de Montpellier, Montpellier, France
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