First genotyping of Enterocytozoon bieneusi in plateau pikas (Ochotona curzoniae) from the Qinghai Plateau, Northwest China.

Enterocytozoon bieneusi is considered the most common microsporidian species and is frequently detected in humans and various animals worldwide. However, information on E. bieneusi infection in plateau pikas (Ochotona curzoniae) is somewhat limited. Therefore, this study was conducted to determine the infection status and genotype characteristics of E. bieneusi in plateau pikas in China. A total of 33 fresh fecal samples were collected from plateau pikas captured on the Qinghai Plateau. By PCR assay and DNA sequencing of the ITS gene, 5 (15.2%, 5/33) isolates were diagnosed as positive. Sequence analysis revealed the presence of one known sheep-derived genotype, CHS17 (4/5), and a novel E. bieneusi genotype, CHPP1 (1/5), with maximum shared identity with the CHS17 genotype. Phylogenetically, these isolates were clustered into subgroup 1i of zoonotic group 1 with genotypes CHS17 and CHN14 from plateau ruminants, but the new CHP1 genotype formed a cluster separate from those genotypes. This is the first report of E. bieneusi in plateau pikas. The findings suggested that these animals might be potential reservoirs of zoonotic E. bieneusi, and transmission of the pathogen between plateau pikas and sheep probably occurs in the region.