Location: Animal Parasitic Diseases LaboratoryTitle: Occurrence, isolation, and genetic characterization of Toxoplasma gondii from white tailed deer (Odocoileus virginianus) in New Jersey) Author
Submitted to: Journal of Parasitology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/8/2013
Publication Date: 10/1/2013
Citation: Dubey, J.P., Randall, A., Choudhary, S., Ferreira, L., Verma, S., Oliveira, S., Kwok, O.C., Su, C. 2013. Occurrence, isolation, and genetic characterization of Toxoplasma gondii from white tailed deer (Odocoileus virginianus) in New Jersey. Journal of Parasitology. 99:763-769. 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 under cooked meat from infected animals and food and water contaminated with oocysts. In the present study, authors found a very high prevalence of Toxoplasma in deer hunted in New Jersey. The ingestion of infected deer meat can be a source of infection for humans and more importantly for cats that can further spread infection in the environment. The results will be of interest to biologists, parasitologists, and public health workers.
Technical Abstract: White tailed deer (WTD) is an important reservoir host for Toxoplasma gondii. Each yr hundreds of thousands WTD are hunted or die in road accidents in the U.S.A. Humans and animals can become infected with T. gondii by eating infected venison. Wild felids that eat infected deer tissues can shed oocysts and contaminate the environment. In the present study, we tested 264 WTD from New Jersey for T. gondii infection during the 2011-2012 hunting season. Serum samples were tested for antibodies to T. gondii by the modified agglutination test starting at 1:25 serum dilution; 76 (28.7%) of 264 WTD were seropositive. Heart muscle samples from 64 seropositive WTD were digested in pepsin and the digests were bioassayed in mice for the isolation of T. gondii. Viable T. gondii was isolated from the myocardium of 9 WTD; tachyzoites from infected mouse tissues were further propagated in cell culture. One of the 9 strains was virulent for outbred mice Swiss Webster mice. The DNA isolated from culture-derived tachyzoites of these 9 T. gondii isolates was characterized using 11 PCRRFLP markers (SAG1, 5’- and 3’-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). Six genotypes were found, including ToxoDB genotype #2 (Type III), #3 (Type II variant), #4 (Type 12), #216, #220 and #221. The latter 2 were new genotypes that were reported for the first time. This is the first report of T. gondii infection in deer from this region of the U.S.A.