Molecular characterization and new genotypes of <italic>Enterocytozoon bieneusi</italic> in pet chipmunks (<italic>Eutamias asiaticus</italic>) in Sichuan province, China.

Background: <italic>Enterocytozoon bieneusi</italic>, the most commonly identified microsporidian species in humans, is also identified in livestock, birds, rodents, reptiles, companion animals, even wastewater. However, there is no information available on occurrence of <italic>E. bieneusi</italic> in pet chipmunks. The aim of the present study was to determine the genotypes, molecular characterization of <italic>E. bieneusi</italic> in pet chipmunks, and assess the zoonotic potential. Results: A total of 279 fecal specimens were collected from chipmunks from seven pet shops and one breeding facility in Sichuan province, China. The prevalence for <italic>E. bieneusi</italic> was 17.6% (49/279) based on nested PCR targeting the internal transcribed spacer (<italic>ITS</italic>) region<italic>.</italic> The prevalence of <italic>E. bieneusi</italic> in chipmunks < 90 days of age was significantly higher than that in older chipmunks; however, differences among different sources and between genders were not significant. Eight genotypes of <italic>E. bieneusi</italic> were identified, including four known genotypes (D, Nig7, CHG9, and CHY1) and four novel genotypes (SCC-1 to 4). Phylogenetic analysis classified these genotypes into four distinct groups as follows: genotypes D and CHG9 clustered into group 1 of zoonotic potential; genotypes Nig7 and CHY1 clustered into group 6 and a new group, respectively; the four novel genotypes (SCC-1 to 4) formed a separate group named group 10. Conclusions: To the best of our knowledge, this is the first study reporting the prevalence and genotypes of <italic>E. bieneusi</italic> in pet chipmunks in China. Genotypes D and Nig7, found in chipmunks in this study, have also been previously identified in humans, which suggests that chipmunks might play a role in the transmission of this pathogen to humans. [ABSTRACT FROM AUTHOR]