Isolation and RFLP Genotyping of Toxoplasma gondii in Free-Range Chickens (Gallus domesticus) in Grenada, West Indies, Revealed Widespread and Dominance of Clonal Type III Parasites

J Parasitol. 2017 Feb;103(1):52-55. doi: 10.1645/15-945. Epub 2016 Oct 24.

Abstract

The objectives of the present cross-sectional study were to isolate and genotype Toxoplasma gondii in free-range chickens from Grenada, West Indies. Using the modified agglutination test, antibodies to T. gondii were found in 39 (26.9%) of 145 free-range chickens with titers of 25 in 7 chickens, 50 in 6 chickens, 100 in 2 chickens, and 200 or higher in 24 chickens. The hearts of the 39 seropositive chickens were bioassayed in mice; viable T. gondii was isolated from 20 and further propagated in cell culture. Genotyping of T. gondii DNA extracted from cell-cultured tachyzoites using the 10 PCR-restriction fragment length polymorphism (RFLP) markers SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico revealed 4 genotypes, including ToxoDB PCR-RFLP no. 2 (Type III), no. 7, no. 13, and no. 259 (new). These results indicated that T. gondii population genetics in free-range chickens seems to be moderately diverse with ToxoDB no. 2 (Type III) as the most frequent (15/20 = 75%) compared to other genotypes in Grenada.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agglutination Tests / veterinary
  • Animals
  • Antibodies, Protozoan / blood
  • Biological Assay / veterinary
  • Chickens / parasitology*
  • Cross-Sectional Studies
  • Genotype
  • Genotyping Techniques / veterinary*
  • Grenada / epidemiology
  • Heart / parasitology
  • Mice
  • Polymerase Chain Reaction
  • Polymorphism, Restriction Fragment Length*
  • Poultry Diseases / epidemiology
  • Poultry Diseases / parasitology*
  • Seroepidemiologic Studies
  • Toxoplasma / classification
  • Toxoplasma / genetics
  • Toxoplasma / immunology
  • Toxoplasma / isolation & purification*
  • Toxoplasmosis, Animal / epidemiology
  • Toxoplasmosis, Animal / parasitology*

Substances

  • Antibodies, Protozoan