Location: Animal Parasitic Diseases LaboratoryTitle: A new atypical genotype mouse virulent strain of Toxoplasma gondii isolated from the heart of a wild caught puma (Felis concolor) from Durango, Mexico) Author
Submitted to: Veterinary Parasitology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/3/2013
Publication Date: 10/1/2013
Publication URL: http://handle.nal.usda.gov/10113/58236
Citation: Dubey, J.P., Alvarado-Esquivel, C., Herrera-Valenzuela, V., Gayosso-Dominguez, E., Oliveira, S., Verma, S., Choudhary, S., Kwok, O.C., Su, C. 2013. A new atypical genotype mouse virulent strain of Toxoplasma gondii isolated from the heart of a wild caught puma (Felis concolor) from Durango, Mexico. Veterinary Parasitology. 197:674-677. 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. The authors report first isolation of Toxoplasma from a wild cougar in Mexico, indicating that wild cats can spread Toxoplasma in urban environment. The results will be of interest to biologists, parasitologists, and public health workers.
Technical Abstract: Nothing is known of the genetic diversity of Toxoplasma gondii circulating in wildlife in Mexico. In the present study, a mouse virulent T. gondii strain was isolated from the heart of a wild puma (Felis concolor). The puma was found roaming in outskirt of Durango City, Mexico and tranquailized for moving to a zoo. The puma died during translocation and a necropsy examination was performed. The puma had an antibody titer of 200 by the modified agglutination test. Its heart and brain tissue were bioassayed in 2 outbred Swiss Webster (SW) and 1 gamma interferon gene knockout (KO) mouse. The KO mouse and the 2 SW mice that became infected after inoculated with homogenate of puma heart died of acute toxoplasmosis 12, 19 and 20 days p.i. respectively and tachyzoites were found in lungs of all 3 mice. None of the 4 SW and 1 KO mouse inoculated with digest of the puma brain became infected with T. gondii. Tachyzoites from the lungs of mice were propagated in cell cultures. Tachyzoites from cell culture were inoculated in to 5 SW; the mice died or had to be killed 14 days p.i. and a cat fed tissues of these mice shed T. gondii oocysts. Results of mortality and infectivity of tachyzoites and oocysts in SW mice indicated that the puma T. gondii strain (designated TgPumaMe1) was virulent for outbred mice. DNA isolated from culture-derived tachyzoites was characterized using 11 PCR-RFLP markers (SAG1, 5’- and 3’-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) revealed a new genotype (ToxoDB PCR-RFLP #222). Isolation of atypical genotype T. gondii from wild puma indicates that mouse virulent strains are circulating in wildlife in Mexico.