Submitted to: Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2009
Publication Date: 5/15/2009
Citation: Dubey, J.P., Moura, L., Sundar, N., Velmurugan, G.V., Kwok, O.C., Kelly, P., Krecek, R.C., Majumdar, D., Su, C. 2009. Isolation and characterization of viable Toxoplasma gondii isolates revealed possible high frequency of mixed infection in feral cats (felis domesticus) from St. Kitts, West Indies. Parasitology. 136:589-594. 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 an University in St Kitts, West Indies first genetic characterization of Toxoplasma from cats from this country. The results will be of interest to biologists, parasitologists, and veterinarians
Technical Abstract: Cats are essential in the epidemiology of Toxoplasma gondii because they are the only hosts that can excrete the environmentally resistant oocysts in nature. Samples of serum, feces, and tissues from feral cats from St. Kitts, West Indies were examined for T. gondii infection. Antibodies to T. gondii were assayed by the modified agglutination test, and found in 71 of 96 (73.9 %) of cats with titers of 1:10 in six, 1:20 in six,1:40 in seven,1: 80 in three, 1: 160 in 10, 1:320 in 13, 1:640 in nine, and 1:1,280 or higher in 17. Tissues of 10 cats were bioassayed in mice. Toxoplasma gondii was isolated from tissues of seven cats; from hearts of six, from tongue of five, and brains of three cats. All seven isolates were avirulent for mice. Toxoplasma gondii oocysts were not found in feces of 51 cats. Genotyping of these seven T. gondii isolates by 10 multi-locus PCR-RFLP markers, including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and an apicoplast marker Apico revealed four genotypes, including clonal Type II, Type III and two unique genotypes. Five of the seven cats had potential infection with mixed genotypes.