Until recently,
Toxoplasma gondii
was considered to be clonal with little genetic variability. In this paper we summarize
recent genotyping data from chickens in Brazil, and pigs, lambs and white-tailed deer in the USA, to demonstrate
the high genetic diversity and geographical distribution of
T. gondii. A total of 149
T. gondii isolates from 13 geographical
areas of Brazil and 182
T. gondii isolates from pigs, 53 isolates from sheep and 15 isolates from fetal white-tailed
deer from USA were genotyped using the 10 RCFP-PCR genetic markers SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-
2, L358, PK1 and Apico. Genotyping of 149
T. gondii isolates from free range chickens in Brazil identified 58 genotype
groups. No clonal type II lineage was found. Of the 253 isolates from animals from USA, 18 genotypes were identified,
predominantly type II. These studies indicate a higher genetic diversity than previously recognized.
