Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/6/2004
Publication Date: 2/8/2004
Citation: Sreekumar, G., Graham, D.H., Dahl, E., Lehmann, T., Raman, M., Bhalerao, D.P., Vianna, M.C., Dubey, J.P. 2004. Genotyping of Toxoplasma gondii isolates from chickens from India. Veterinary Parasitology. 118:187-194. Interpretive Summary: Infection by the single-celled parasite, Toxoplasma gondii, is common in man and animals. Humans become infected by eating undercooked infected meat or ingesting the resistant stage of Toxoplasma (oocysts) in the environment. Infections in free range-range chickens is indicative of Toxoplasma infection in the environment because chickens feed from the ground. Scientists at the Beltsville Agricultural Research Center and Centers for Disease Control, Atlanta, Georgia, report isolation and moecular characterization of toxoplasma gondii strains from free-range chickens from India for the first time. These results will be of interest to public health workers, parasitologists and veterinarians.
Technical Abstract: The present study was undertaken to isolate and genotype Toxoplasma gondii from free range chickens (Gallus domesticus) from villages in Maharashtra and Tamil Nadu states of Central and South India, respectively. Blood, heart, and brain from a total of 741 chickens were examined for T. gondii infection. Antibodies to T. gondii, as assayed with the modified agglutination test (MAT ' 1:5) were found in 133 (17.9%) chickens. Hearts and brains of 186 chickens were bioassayed in mice. Additionally, hearts and/ or brains of most of the seronegative (MAT <1:5) chickens were fed to 20 T. gondii-free cats, while 32 seropositive chickens (MAT 1:5) were fed to 3 cats. T. gondii was not isolated from any of the chickens by mouse bioassay. Five of the cats that were fed seronegative chickens shed oocysts, while isolates were not obtained from any of the other cats fed seropositive chickens. These 5 isolates, along with the 2 that were previously isolated in India through cat bioassay, were genetically analyzed. Genotyping using the SAG 2 locus indicated that 2 isolates were type II and 5 were type III. Microsatellite analysis revealed allelic differences between and within the lineages. This is the first report of genetic characterization of any T. gondii isolate from India