ARS | Publication request: CHARACTERIZATION OF TOXOPLASMA GONDII ISOLATES FROM CATS FROM COLOMBIA, SOUTH AMERICA

Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 28, 2006
Publication Date: August 1, 2006
Citation: Dubey, J.P., Su, C., Vecino, J.C., Sundar, N., Gomez, J.E., Lora, F., Jimenez, J., Kwok, O.C., Shen, S.K., Zhang, X., Nieto, A. 2006. Characterization of Toxoplasma gondii isolates from cats from Colombia, South America. Veterinary Parasitology. 141:42-47.

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 a university in Colombia, South America report the first genetic characterization of Toxoplasma from cats from Colombia. The results will be of interest to biologists, parasitologists, and veterinarians.

Technical Abstract: Cats are important in the epidemiology of Toxoplasma gondii infection because they are the only hosts that can excrete the environmentally-resistant oocysts. In the present study, prevalence of T. gondii was determined in serum, feces, and tissues 170 unwanted cats from Colombia, South America. Antibodies to T. gondii were assayed by the modified agglutination test and found in 77 of 170 ( 45.2 %) cats with titers of < 1:5 in 93, 1: 5 in eight,1:10 in 17, 1:20 in 10, 1:40 in seven, 1:80 in four, 1:160 in eight, 1:320 in six, and 1:640 or higher in 17 cats. T. gondii oocysts were not found in feces of any cat as ascertained by bioassay in mice. Tissues (brain, heart, tongue) of 116 cats were bioassayed in mice or cats. T. gondii was isolated from tissues of 15 of the 42 cats with titers of 1:40 or higher and not from any of the 90 cats titers of 1:20 or lower. Of the 29 cats whose tissues were bioassayed individually, T. gondii was isolated from the tongues of nine, hearts of eight, and brains of five. Mice inoculated with tissues of 12 of 15 infected cats died of toxoplasmosis; with nine T. gondii isolates all infected mice died. Overall, 65 of 92 (70%) of T. gondii–infected mice died of toxoplasmosis. Genotyping of these 14 isolates using polymorphisms at the loci SAG1, SAG2, SAG3, BTUB and GRA6 revealed 5 genotypes. Two isolates had type I alleles and 1 isolate had type II alleles at all loci. The rest 11 isolates contained the combination of type I and III alleles and were divided into three genotypes.