Detection of Toxoplasma gondii in cats by comparing bioassay in mice and polymerase chain reaction (PCR).

Feline toxoplasmosis can usually be diagnosed by serological and coprological methods. However, when the interpretation of results is difficult, it becomes necessary to rely on the direct detection of the parasite. In this study, samples of brain from 64 Toxoplasma-seropositive cats were subjected to direct detection of Toxoplasma gondii by bioassay in mice and nested-PCR. T. gondii was isolated by bioassay in mice in 41 (64%) cases, and nested-PCR was positive in 37 (57.8%) cases (p>0.05). The results therefore suggest that nested-PCR could be a rapid technique for diagnosing toxoplasmosis in cats.