Determination of the viability of Toxoplasma gondii oocysts by PCR real-time after treatment with propidium monoazide.

This study aimed to investigate a methodology for discriminating viable and non-viable T. gondii oocysts in water. Analyses included two steps: (i) microscopic investigation with vital dyes; (ii) molecular investigation, using a real time PCR (qPCR), after parasite treatment (or not) with propidium monoazide (PMA). The method was called qPCR-PMA. Oocyst aliquots were incubated (15 min) at 25 ºC or 100 ºC and analyzed by microscopy, after trypan blue and neutral red staining. Microscopic investigation determined viable and non-viable oocysts. For the molecular investigation, both aliquots of oocysts were treated with PMA. Non-viable oocysts, after PMA treatment, exhibited an inhibition of DNA amplification by qPCR. Although analyses were carried out with oocysts treated experimentally, these results suggest that qPCR-PMA can be a useful strategy to distinguish viable and non-viable T. gondii oocysts in water safety testing, showing if water is safe to drink.

Citation

Maria Aparecida Moraes Marciano, Rafaela Aparecida Silva, Maria Luisa Barbosa, Antônio Roberto Souza Ferreira, Vera Lucia Pereira-Chioccola. Determination of the viability of Toxoplasma gondii oocysts by PCR real-time after treatment with propidium monoazide. Revista do Instituto de Medicina Tropical de Sao Paulo. 2020;62:e84

Mesh Tags

Substances

PMID: 33146312

search → result