Enterocytozoon bieneusi in Dairy Cattle in the Northeast of China: Genetic Diversity of ITS Gene and Evaluation of Zoonotic Transmission Potential.

Enterocytozoon bieneusi is the most frequently diagnosed microsporidian species in humans. It has been found in a wide range of animals and is considered an important zoonotic pathogen. To date, little information is available on the role that cattle play in the epidemiology of human microsporidiosis caused by E. bieneusi in China. In this study, 133 fecal specimens from dairy cattle were collected in Heilongjiang Province, China. Enterocytozoon bieneusi was identified and genotyped by nested PCR analysis of the internal transcribed spacer (ITS) region of the rRNA gene, with 30.1% positive. Nine ITS genotypes were identified: six known genotypes-O (n = 26), EbpA (n = 2), I (n = 2), J (n = 2), D (n = 1) and BEB4 (n = 1)-and three novel genotypes named as CC-I to CC-III (two each). Genotype O was identified in cattle for the first time. The observation of all the six known genotypes here reported previously in humans, and also the fact of all the three novel genotypes (CHN-DC1 to CHN-DC3) falling into zoonotic group 1, indicate the possibility of cattle in the transmission of E. bieneusi to humans.