To better assess the zoonotic transmission of giardiasis and differentiate mixed infections of assemblages, high-resolution multilocus genotyping analysis using more intra-assemblage variation genes, including β-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes, has been widely used to characterize G. duodenalis isolates from humans and animals [1, 15]. The gene discussed is TPI1; the disease is infection.