Toxoplasmosis is a zoonotic disease caused by the protozoan Toxoplasma gondii. Infections occur via the ingestion of oocysts, consumption of cysts containing bradyzoites, and transplacental transmission of tachyzoites. Diversity in T. gondii strains may affect the outcome of clinical toxoplasmosis. The consumption of horse meat is a common practice in some parts of the world. The objectives of the present study were to isolate and genotype T. gondii from horses from an abattoir in the state of Rio Grande do Sul in southern Brazil that exports horse meat to Europe. Antibodies to T. gondii were found in 32.5% (13/40) of the horses using the modified agglutination test (MAT) with a cut-off of 1:25. Tissues from the 13 seropositive horses were bioassayed in mice, and one isolate, designated TgHorseBrRS1, was obtained. PCR-RFLP of the isolate revealed the ToxoDB-RFLP #228 genotype, a typical non-archetypal Brazilian genotype, and microsatellite analysis showed a unique non-archetypal genotype. This study showed that horses from Brazil can harbor viable T. gondii in their tissues, suggesting that recommendations to consumers should be made, especially in European countries where consumption of raw horse meat is common.
Keywords: Brazil; Diversity; Horse meat; Microsatellites; PCR-RFLP; Toxoplasmosis.