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United States Department of Agriculture

Agricultural Research Service

Research Project: INTEGRATED APPROACH TO THE DETECTION AND CONTROL OF FOODBORNE PARASITES AND THE IMPACT ON FOOD SAFETY

Location: Animal Parasitic Diseases

Title: Isolation and genetic characterization of Toxoplasma gondii from the gray wolf Canis lupus

Authors
item Dubey, Jitender
item Choudhary, Shanti -
item Ferreira, Leandra -
item Kwok, Oliver
item Butler, Erika -
item Carstensen, Michelle -
item Yu, L -
item Su, Chunlei -

Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 11, 2013
Publication Date: October 1, 2013
Citation: Dubey, J.P., Choudhary, S., Ferreira, L., Kwok, O.C., Butler, E., Carstensen, M., Yu, L., Su, C. 2013. Isolation and genetic characterization of Toxoplasma gondii from the gray wolf Canis lupus. Veterinary Parasitology. 197:685-690.

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. Little is known of the circulation of Toxoplasma in wildlife. In the present study, scientists found Toxoplasma in wolves for the first time. Isolation of T. gondii from feral wolves indicates a sylvatic cycle of Toxoplasma, with spillover to domestic livestock. The results will be of interest to biologists, parasitologists, and public health workers.

Technical Abstract: Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study feral gray wolf (Canis lupus) from Minnesota were examined for T. gondii infection. Antibodies to T. gondii were detected in 130 (52.4%) of 248 wolves tested by the modified agglutination test (cut-off titer of 25). Tissues (hearts, brains or both) of 109 wolves were bioassayed in mice for isolation of parasites. Viable T. gondii was isolated from 25 and the isolates were further propagated in cell culture. T. gondii DNA from these isolates was characterized using 10 PCR-RFLP markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). Four genotypes were detected. Twenty-one isolates were Type 12 (ToxoDB PCR-RFLP genotype #5), 2 were Type II clonal (ToxoDB #1), 1 was Type II variant (ToxoDB #3), and 1 was a new genotype designated as ToxoDB genotype #219.

Last Modified: 4/15/2014