Molecular characterization of Giardia psittaci by multilocus sequence analysis

► We analyzed Giardia psittaci molecularly by sequence analysis of SSU rDNA, ef1α, β-giardin, gdh. ► Phylogenetic analysis of G. psittaci shows it to be distinct from known Giardia species. ► Allelic sequence heterogeneity, observed in Giardia duodenalis, was found at ef1α in G. psittaci. ► No sequence differences at highly variable regions (gdh, β-giardin) were found in G. psittaci. ► G. psittaci might not be as diverse genetically as other Giardia species.