Detection and genotyping of Giardia duodenalis infecting pigs and small ruminants in the state of Piauí, northeastern Brazil

Genotipagem e relações filogenéticas de Giardia duodenalis infectando suínos, caprinos e ovinos no nordeste do Brasil, avaliadas por sequenciamento parcial do gene da β-giardina

ABSTRACT:

This study performed a molecular detection and characterization of Giardia duodenalis infecting pigs, goats and sheep in rural and peri-urban communities in the state of Piauí, northeastern Brazil, and proposed phylogenetic relationships among the characterized parasites. We assessed 52 fecal samples from pigs, 13 from goats, and 10 from sheep. A fragment of the β-giardin locus was PCR-amplified and sequenced. Overall, PCR-based G. duodenalis positivity was 11/52 (21.2%) in pigs, 2/13 (15.4%) in goats, and 2/10 (20%) in sheep. Seven out of 15 successfully amplified samples could be sequenced: three from pigs, two from goats, and two from sheep. Parasites from different hosts were found to belong to sub-assemblage AII. The phylogenetic analyses of the original G. duodenalis AII β-giardin sequences obtained from distinct host species and sequences of G. duodenalis recovered from humans available in GenBank suggest that the parasites are genetically related, supporting a local scenario of cross-host transmission.

INDEX TERMS:
Giardia duodenalis; pigs; goat; sheep; β-giardin; DNA sequencing; Brazil