First molecular characterisation of Giardia duodenalis infection in dairy goats in Brazil.

The aim of this study was to perform the first molecular genotyping of Giardia duodenalis from goats in Brazil, in order to assess the risk for zoonotic transmission. Samples were collected from two dairy goat farms (Saanen breed) located in the city of Niteroi in the state of Rio de Janeiro, Brazil. Goat faecal samples (n = 58) were collected directly from the rectums of all animals up to one year of age and were subjected to centrifuge-flotation in sugar saturate solution. Nested-PCR and sequencing using β-giardin and tpi gene targets was performed on positive samples. Seventeen out of fifty-eight (29.31%) faecal samples were positive for Giardia duodenalis cysts, all belonging to the same farm. Only eight isolates were successfully sequenced (eight samples for β-giardin and four samples for tpi), all belonging to genotype E. Two types of sequences were identified for each locus within isolates from the current study, which exhibited sequence heterogeneity with variable numbers of single nucleotide polymorphisms. The present study contributes to a better understanding of the molecular epidemiology of this parasite.