Related Experiment Video
Updated: Aug 19, 2026
Obtaining Highly Purified Toxoplasma gondii Oocysts by a Discontinuous Cesium Chloride Gradient
Published on: November 3, 2009
Isolation and genotyping of Toxoplasma gondii from free-ranging chickens from Mexico
J P Dubey1, E S Morales, T Lehmann
1United States Department of Agriculture, Agricultural Research Service, Animal and Natural Resources Institute, Animal Parasitic Diseases Laboratory, Building 1001, Beltsville, Maryland 20705-2350, USA. jdubey@anri.barc.usda.gov
Abstract:
The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the presence of T. gondii oocysts in the environment because chickens feed from the soil. In the present study, prevalence of T. gondii in 208 free-range chickens (Gallus domesticus) from Mexico was investigated. Blood, heart, and brain from each animal were obtained to test for T. gondii infection. Antibodies to T. gondii, assayed with the modified agglutination test (1:10 or higher), were found in 13 (6.2%) chickens. Hearts and brains of 13 seropositive chickens were bioassayed in mice, and T. gondii was isolated from 6 chickens. All 6 isolates were avirulent for mice. Genotyping of chicken isolates of T. gondii using the SAG2 locus indicated that 5 were type III and 1 was type I. This is the first report of isolation of T. gondii from chickens from Mexico.
