Enterocytozoon bieneusi genotypes in yaks (Bos grunniens) and their public health potential.

Enterocytozoon bieneusi, the most frequently diagnosed microsporidian species in humans, is also identified in a wide range of animals. To date, few data are available on E. bieneusi in yaks (Bos grunniens). In this study, we examined the occurrence and genotype identity of E. bieneusi in yaks in four counties in Qinghai Province of China. Of 327 fecal specimens examined by nested PCR analysis of the ribosomal internal transcribed spacer, 23 (7.0%) were E. bieneusi-positive. DNA sequence analysis of the PCR products revealed the presence of five distinct genotypes: three Group 2 genotypes previously reported in cattle as well as humans (BEB4, I and J) and two novel genotypes (CHN11 and CHN12) belonging to the large zoonotic group (Group 1). Data of the study suggest that these animals could be potential reservoirs for human E. bieneusi infection.