A rapid and sensitive method to detect Toxoplasma gondii oocysts in soil samples.
Fiche publication
Date publication
octobre 2019
Journal
Veterinary parasitology
Auteurs
Membres identifiés du Cancéropôle Est :
Pr VILLENA Isabelle
Tous les auteurs :
Escotte-Binet S, Da Silva AM, Cancès B, Aubert D, Dubey J, La Carbona S, Villena I, Poulle ML
Lien Pubmed
Résumé
Documenting the extent of soil contamination by Toxoplasma gondii oocysts is a key issue to prevent the worldwide infection caused by this protozoan. Our aim was to improve the practicability and sensitivity of a low-cost method to detect T. gondii DNA in soil samples developed a few years ago. Various parameters of the reference protocol were modified to determine their effect on the detection of T. gondii DNA in soil samples ("natural soil" and "sand") spiked with oocysts. We tested i) filtration using stomacher bags, ii) Tween 80, Tween 20, SDS and Triton X100 as dispersion solutions, iii) sucrose solution, zinc chloride solution, Optiprep and Percoll as density gradients, iv) freeze/thaw versus mechanical grinding as lysis methods, and v) Qiagen versus Fastprep as extraction kits The optimized protocol is quicker and easier to use than the previous one, and includes the following items: 0.1% Tween80/PBS for dispersion, sucrose solution for flotation, mechanical grinding, and FastDNA spin kit for extraction. It accurately detects T. gondii DNA in both fresh and frozen soil samples and displays a detection limit below 1 oocyst/g of fresh soil.
Mots clés
Density gradients, Dispersion solution, Soil contamination, Sucrose flotation, Toxoplasma gondii, qPCR detection
Référence
Vet Parasitol. 2019 Oct;274:108904