Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2007
Publication Date: 12/5/2007
Citation: Dubey, J.P., Lopez-Torres, N.Y., Sundar, N., Velmurugan, G.V., Kwok, O.C., Hill, R., Su, C. 2007. Mouse-virulent Toxoplasma gondii from feral cats in Mona Island, Puerto Rico. Journal of Parasitology. 93:1265-1369.
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. Toxoplasmosis causes mortality in many species of animals in the zoos, especially primates. Scientists at the Beltsville Agricultural Research Center and Department of Natural Resources in Puerto Rica report characteristics of Toxoplasma isolates from cats from a remote island . The results will be of interest to biologists, parasitologists, and veterinarians
Technical Abstract: Cats are essential in the life cycle of Toxoplasma gondii because they are the only hosts that can excrete the environmentally-resistant oocysts. Samples of serum, feces, and tissues from cats from Mona, a remote island off the coast of Puerto Rico were examined for T. gondii infection. Antibodies to T. gondii were assayed by the modified agglutination test, and found in 16 of 19 (84.2 %) of cats with titers of 1:10 in 2, 1: 80 in 1, 1: 160 in 4, 1:320 in 3, and 1:1,280 or higher in 6. Tissues of 19 of the 20 cats were bioassayed in mice for T. gondii infection. Toxoplasma gondii was isolated from tissues of 12 cats; from the hearts of 10, skeletal muscle of 10, and brain of 1 cat. All infected mice from 10 of 12 isolates died of acute toxoplasmosis during primary infection. Genotyping of these 12 T. gondii isolates by multi-locus PCR-RFLP markers SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and an apicoplast marker Apico revealed 6 genotypes; 5 isolates had Type I alleles at all loci and the remainders were atypical. These isolates of T. gondii were different biologically and phenotypically from the feline isolates from the rest of Americas.