title: Isolation, tissue distribution, and molecular characterization of Toxoplasma gondii from chickens in Grenada, West Indies.
abstract: The prevalence of Toxoplasma gondii in free-range 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 102 free-range chickens (Gallus domesticus) from Grenada was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT). Antibodies were found in 53 (52%) chickens with titers of 1:5 in 6, 1:10 in 4, 1:20 in 4, 1:40 in 4, 1:80 in 15, 1:160 in 9, 1: 320 in 5, 1:640 in 4, and 1:1,280 or greater in 2. Hearts, pectoral muscles, and brains of 43 seropositive chickens with MAT titers of 1:20 or greater were bioassayed individually in mice. Tissues of each of 10 chickens with titers of 1:5 and 1:10 were pooled and bioassayed in mice. Tissues from the remaining 49 seronegative chickens were pooled and fed to 4 T. gondii-free cats. Feces of cats were examined for oocysts; they did not shed oocysts. T. gondii was isolated from 35 of 43 chickens with MAT titers of 1:20 or greater; from the hearts, brains, and pectoral muscles of 2, hearts and brains of 20, from the hearts alone of 11, and brains alone of 2. T. gondii was isolated from 1 of 10 chickens with titers of 1:5 or 1:10. All 36 T. gondii isolates were avirulent for mice. Genotyping of these 36 isolates using polymorphisms at the SAG2 locus indicated that 29 were Type III, 5 were Type I, 1 was Type II, and 1 had both Type I and Type III. Genetically, the isolates from Grenada were different from those from the United States; Type II was the predominant type from the United States. Phenotypically, all isolates from Grenada were avirulent for mice, whereas those from Brazil were mouse-virulent. This is the first report of isolation of T. gondii from chickens from Grenada, West Indies.
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 R
authors.initials: JR
authors.lastname: Dubey
authors.forename: M I
authors.initials: MI
authors.lastname: Bhaiyat
authors.forename: C
authors.initials: C
authors.lastname: de Allie
authors.forename: C N L
authors.initials: CN
authors.lastname: Macpherson
authors.forename: R N
authors.initials: RN
authors.lastname: Sharma
authors.forename: C
authors.initials: C
authors.lastname: Sreekumar
authors.forename: M C B
authors.initials: MC
authors.lastname: Vianna
authors.forename: S K
authors.initials: SK
authors.lastname: Shen
authors.forename: O C H
authors.initials: OC
authors.lastname: Kwok
authors.forename: K B
authors.initials: KB
authors.lastname: Miska
authors.forename: D E
authors.initials: DE
authors.lastname: Hill
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 / Q000662:veterinary; D001921:Brain / Q000469:parasitology; D002415:Cats; D002645:Chickens / Q000469:parasitology*; D016054:DNA, Protozoan / Q000737:chemistry; D005260:Female; D005838:Genotype; D019425:Grenada / Q000453:epidemiology; D006321:Heart / Q000469:parasitology; D051379:Mice; D010369:Pectoralis Muscles / Q000469:parasitology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012150:Polymorphism, Restriction Fragment Length; D011201:Poultry Diseases / Q000453:epidemiology* / Q000469:parasitology; D015995:Prevalence; D014122:Toxoplasma / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D014124:Toxoplasmosis, Animal / Q000453:epidemiology* / Q000469:parasitology
chemical_list: D000913:Antibodies, Protozoan; D016054:DNA, Protozoan