title: Characterization of Toxoplasma gondii isolates in free-range chickens from Amazon, Brazil.
abstract: The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 50 free-range chickens (Gallus domesticus) from Amazon, Brazil, was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT) and found in 33 (66%) chickens with titers of 1:5 in 3, 1:10 in 2, 1:20 in 1, 1:40 in 1, 1:80 in 2, 1:160 in 5, 1:200 in 9, 1:400 in 5, 1:800 in 2, 1:1,600 in 2, and 1:3,200 or higher in 1. Hearts and brains of 33 seropositive chickens were bioassayed individually in mice. Tissues from 17 seronegative chickens were pooled and fed to 2 T. gondii-free cats. Feces of cats were examined for oocysts, but none was found. Toxoplasma gondii was isolated from 24 chickens with MAT titers of 1:5 or higher. Genotyping of these 24 T. gondii isolates by polymorphisms at the SAG2 locus indicated that 14 were type I, and 10 were type III; the absence of type II strains from Brazil was confirmed. Fifty percent of the infected mice died of toxoplasmosis, irrespective of the genotype.
authors.affiliation: United 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
authors.forename: J P
authors.initials: JP
authors.lastname: Dubey
authors.forename: Solange M
authors.initials: SM
authors.lastname: Gennari
authors.forename: Marcelo B
authors.initials: MB
authors.lastname: Labruna
authors.forename: Luis M A
authors.initials: LM
authors.lastname: Camargo
authors.forename: M C B
authors.initials: MC
authors.lastname: Vianna
authors.forename: Paula L
authors.initials: PL
authors.lastname: Marcet
authors.forename: T
authors.initials: T
authors.lastname: Lehmann
mesh_terms: D000372:Agglutination Tests / Q000662:veterinary; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001681:Biological Assay / Q000379:methods / Q000662:veterinary; D001921:Brain / Q000469:parasitology; D001938:Brazil; D002415:Cats; D002645:Chickens / Q000469:parasitology*; D005243:Feces / Q000469:parasitology; D005838:Genotype; D006321:Heart / Q000469:parasitology; D051379:Mice; D033661:Oocysts / Q000302:isolation & purification; D011201:Poultry Diseases / Q000469:parasitology*; D014122:Toxoplasma / Q000276:immunology / Q000302:isolation & purification* / Q000472:pathogenicity; D014124:Toxoplasmosis, Animal / Q000469:parasitology*
chemical_list: D000913:Antibodies, Protozoan