Submitted to: Parasitology Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 28, 1997
Publication Date: N/A
Interpretive Summary: Infections by the protozoan (single celled) parasite, Toxoplasma gondii are widely prevalent in man and animals throughout the world. Humans become infected with T. gondii by ingesting tissue cysts from infected meat, by ingesting food or water contaminated with oocysts or congenitally. Cats are the only hosts that can excrete environmentally resistant T. gondii (oocysts). Cats become immune to T. gondii after primary infection and usually do not shed oocysts for the second time. However, little is known of the parasite stages that initiate immunity to oocysts in the intestines of the cats. Scientists at the Beltsville Agricultural Research Center and Obihiro University in Japan have for the first time developed techniques to separate T. gondii stages from the intestine of infected cats. These results will be of use to study the basic biology of the parasite and would be of interest to biologists, veterinarians and parasitologists.
A method for isolation of enteroepithelial stages of Toxoplasma gondii from the intestinal mucosa of experimentally infected cats was developed using Percoll density gradient centrifugation. Gamonts and merozoites were obtained essentially free of host cell debris. A recovery rate of nearly 30% of the parasites in the original preparations was obtained by this method. Merozoites were separated from gamonts by filtration through a 3 um polycarbonate filter.