Genetic characteristics of Giardia duodenalis from sheep in Inner Mongolia, China

Giardia duodenalis is an important zoonotic pathogen for both human and animal health. Although there have been reports on G. duodenalis infections in animals all over the world, information regarding the prevalence and genetic characteristics of G. duodenalis in sheep in Inner Mongolia, China, is limited. In this study, 209 sheep fecal specimens were collected in this autonomous region. We established that the prevalence of G. duodenalis was 64.11% (134/209), as determined using nested PCR detection and sequences analysis of the small subunit ribosomal RNA (SSU rRNA) gene. Based on the beta-giardin (bg) locus, the glutamate dehydrogenase (gdh) locus, and the triose phosphate isomerase (tpi) locus to study genetic characteristics, both assemblages A (2.99%, 4/134) and E (97.01%, 130/134) were found. Five novel nucleotide sequence of assemblage E were detected, two at the bg locus, two at the gdh locus, and one at the tpi locus. Multilocus genotyping yielded four assemblage E and two assemblage A multilocus genotypes (MLGs), including four novel assemblage E MLGs and one novel assemblage A MLG. Results of this study indicated that G. duodenalis was highly prevalent in sheep in Inner Mongolia. This study is the first to use the multilocus genotyping approach to identify G. duodenalis in sheep from this region.