Submitted to: Journal of Parasitology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/1/2011
Publication Date: 10/1/2011
Citation: Dubey, J.P., Passos, L.M., Chelaiah, R., Ferreira, L., Gennari, S.M., Su, C. 2011. Isolation of viable Toxoplasma gondii from guinea fowl (Numida meleagris) and rabbits from Brazil. Journal of Parasitology. 97:842-845. Interpretive Summary: Toxoplasma gondii is a single-celled parasite of all warm-blooded hosts worldwide. It causes mental retardation and loss of vision in children, and abortion in livestock. Cats are the main reservoir of T. gondii because they are the only hosts that can excrete the resistant stage (oocyst) of the parasite in the feces. Humans become infected by eating undercooked meat from infected animals and food and water contaminated with oocysts. Why some people become sick whereas others do not is not clear. In the present study scientists document genetic diversity of Toxoplasma in guinea fowl and rabbits. The results will be of interest to biologists, parasitologists, and public health workers.
Technical Abstract: Toxoplasma gondii was isolated from a feral guinea fowl (Numida meleagris) and domestic rabbits from Brazil for the first time. Serum and brains from 10 guinea fowl and 21 rabbits from Brazil were examined for T. gondii infection. Antibodies to T. gondii were found in 2 of 10 fowl and 2 of 21 rabbits by the modified agglutination test (titer 1:25 or higher). Viable T. gondii (designated Tg NmBr1) was isolated from 1 of the 2 seropositive fowl by bioassay in mice, but not from the 8 seronegative fowl by bioassay in cat. Viable T. gondii was isolated from both seropositive rabbits (designated TgRabbitBr1, TgRabbitBr2) by bioassay in mice from 1, and by bioassay in cat from the other. All 3 isolates were grown in cell culture and tachyzoite-derived DNA were genotyped using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). The TgNmBr1 was found to be clonal Type II, a rare finding in Brazil in any host. The rabbit isolates were atypical, similar to isolates from cats from Brazil (TgRabbitBr1 was identical to TgCatBr5, and TgRabbitBr2 was identical to TgCatBr1, a common genotype in Brazil, donoted type BrII). This is the first genetic characterization of T. gondii isolates from the rabbits and guinea fowl in Brazil, and first host record for T. gondii in the guinea fowl.