First detection and genotyping of Enterocytozoon bieneusi in pet golden hamsters (Mesocricetus auratus) and Siberian hamsters (Phodopus sungorus) in China

Enterocytozoon bieneusi, a common opportunistic pathogen, has been detected in humans and a wide range of animals worldwide. However, no information on the prevalence and molecular characterization of E. bieneusi in hamsters is available worldwide. In this study, fecal specimens were collected from 175 golden hamsters and 175 Siberian hamsters purchased from pet shops in three provinces of China. The average infection rate of E. bieneusi was 12.0% (42/350), with 14.9% (26/175) in pet golden hamsters and 9.1% (16/175) in pet Siberian hamsters. Four genotypes were identified in pet golden hamsters, including three known genotypes (D, Henan-II, and SHW5) and one novel genotype (named Ebph1). Five genotypes were found in pet Siberian hamsters, including one known genotype (D) and four novel genotypes (named Ebph2 to Ebph5). Genotypes D and Ebph2 were the dominant genotype in pet golden hamsters (23/26, 88.5%) and Siberian hamsters (9/16, 56.3%), respectively. Phylogenetic analysis showed that the E. bieneusi isolates clustered into two groups: Group 1 (D, Henan-II, SHW5, and Ebph1) and Group 3 (Ebph2 to Ebph5). To the best of our knowledge, this is the first report of E. bieneusi infection in golden hamsters and Siberian hamsters worldwide. The identification of four genotypes belonging to Group 1 of high zoonotic potential suggests that pet hamsters especially golden hamsters can be potential sources of human microsporidiosis.