title: Predominance of atypical genotypes of Toxoplasma gondii in free-roaming chickens in St. Kitts, West Indies.
abstract: Toxoplasma gondii is a worldwide protozoan parasite of felids which can infect almost all warm-blooded animals, including humans. Free-roaming chickens are good indicators of environmental contamination with T. gondii oocysts because they feed from the ground. Previous research has demonstrated a high seroprevalence of T. gondii in domestic animals on St. Kitts but little is known about the genotypes circulating in the environment.
  
  
  
  Hearts and brains from 81 free-roaming chickens in St. Kitts were digested and inoculated into 243 Swiss Webster mice in a bioassay. DNA was extracted from digested chicken tissues and the brains of all mice, and screened for T. gondii. Positive samples were genotyped using restriction fragment length polymorphism. Chicken sera were also screened for T. gondii antibodies using a modified agglutination test (MAT).
  
  
  
  Overall, 41% (33 out of 81) of chickens were positive for T. gondii either by serology and/or by PCR. Antibodies to T. gondii were detected by MAT in 32% (26 out of 81) of chickens, and T. gondii DNA was detected in mouse brains representing 26% (21 out of 81) of chickens. Genotyping of 21 DNA isolates, using polymorphisms at 10 loci, including SAG1, SAG2 (5'-3' SAG2 and alt.SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico, revealed that 7 were ToxoDB genotype #141, 6 were #1 (Type II), 3 were #13, 3 were #265, one was #264 and one was #2 (Type III). Genotypes #13 and #141 appear to be more virulent.
  
  
  
  The results of this study highlight the greater genetic diversity of T. gondii circulating in the Caribbean region, with potentially different degrees of virulence to humans.
authors.affiliation: Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ, UK. clare.hamilton@moredun.ac.uk.|Ross University School of Veterinary Medicine, Island Main Road, West Farm, Saint Kitts and Nevis. clare.hamilton@moredun.ac.uk.
authors.forename: Clare M
authors.initials: CM
authors.lastname: Hamilton
authors.affiliation: Ross University School of Veterinary Medicine, Island Main Road, West Farm, Saint Kitts and Nevis.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Kelly
authors.affiliation: Ross University School of Veterinary Medicine, Island Main Road, West Farm, Saint Kitts and Nevis.|School of Applied Science, Temasek Polytechnic, 21 Tampines Avenue 1, Singapore, 529757, Singapore.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Boey
authors.affiliation: Ross University School of Veterinary Medicine, Island Main Road, West Farm, Saint Kitts and Nevis.
authors.forename: Tatiana M
authors.initials: TM
authors.lastname: Corey
authors.affiliation: Ross University School of Veterinary Medicine, Island Main Road, West Farm, Saint Kitts and Nevis.
authors.forename: Hieuhanh
authors.initials: H
authors.lastname: Huynh
authors.affiliation: Ross University School of Veterinary Medicine, Island Main Road, West Farm, Saint Kitts and Nevis.
authors.forename: Deidra
authors.initials: D
authors.lastname: Metzler
authors.affiliation: EA 3800, UFR Medecine, SFR CAP-SANTE, University of Reims Champagne Ardenne, Reims, France.|Laboratory of Parasitology, National Reference Centre on Toxoplasmosis, Hospital Maison Blanche, CHU Reims, Reims, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Villena
authors.affiliation: Department of Microbiology, University of Tennessee, 1414 W. Cumberland Avenue, Knoxville, TN, 37996-0845, USA.
authors.forename: Chunlei
authors.initials: C
authors.lastname: Su
authors.affiliation: Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ, UK.
authors.forename: Elisabeth A
authors.initials: EA
authors.lastname: Innes
authors.affiliation: Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, EH26 0PZ, UK.
authors.forename: Frank
authors.initials: F
authors.lastname: Katzer
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D002645:Chickens; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D051379:Mice; D011110:Polymorphism, Genetic; D011201:Poultry Diseases / Q000097:blood / Q000469:parasitology*; D014122:Toxoplasma / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D014124:Toxoplasmosis, Animal / Q000097:blood / Q000469:parasitology*; D014900:West Indies
chemical_list: D000913:Antibodies, Protozoan
keywords: Chickens; Genotyping; St. Kitts; Toxoplasma gondii; West Indies