Dominance of Giardia duodenalis assemblage A and Enterocytozoon bieneusi genotype BEB6 in sheep in Inner Mongolia, China.

To examine the occurrence and genotype distribution of Giardia duodenalis and Enterocytozoon bieneusi in sheep, fecal specimens were collected from 162 lambs and 213 ewes on seven farms in the Hulunbeier Prairie in Inner Mongolia, China. By PCR analysis of the triose-phosphate isomerase gene, 16 of the 375 (4.3%) specimens were positive for G. duodenalis, with 13 sequenced successfully belonging to assemblage A. Lambs had a significantly higher infection rate than ewes (8.6% versus 0.9%, respectively). The dominance of assemblage A in sheep was supported by PCR analysis of the β-giardin and glutamate dehydrogenase genes; 4 of 7 β-giardin-positive specimens and 3 of 5 glutamate dehydrogenase-positive specimens were identified as assemblage A. A much higher occurrence of E. bieneusi was detected by PCR analysis of the ribosomal internal transcribed spacer; 77.8% of lambs and 62.9% of ewes were positive for the pathogen. Two genotypes of E. bieneusi were found: BEB6 and CM7. Genotype BEB6 was seen in 237 animals and on all seven farms, whereas genotype CM7 was detected in 23 animals from six farms. These data indicate that sheep in Inner Mongolia are commonly infected with G. duodenalis assemblage A and E. bieneusi genotype BEB6, two zoonotic pathogens in China.