Unusual dominant genotype NIA1 of Enterocytozoon bieneusi in children in Southern Xinjiang, China

Author summary This study reports the infection rates and genetic characteristics ofEnterocytozoon bieneusiin 609 children in kindergarten in Southern Xinjiang, China. All samples were screened for this pathogen with PCR, based on the internal transcribed spacer (ITS) ofE.bieneusi. Thirty-six fecal samples (5.9%, 36/609) were positive, with the highest prevalence observed in children from Yopurga (17.5%, 11/63). Three novel genotypes were identified (CXJH1, CXJH2 and CXJH3). Phylogenetic analysis revealed that theE.bieneusiisolates clustered into two groups: Group 1 (A, CXJH1, D, EbpA, KB-1, and NIA1) and Group 2 (CHN6, CXJH2, and CXJH3). Genotype NIA1 used to be detected in HIV-positive patients, however, it was most prevalent (52.8%, 19/36) among the nine genotypes identified in this study. Additionally, we confirmed the zoonotic potential ofE.bieneusigenotype D and this is the first report of human infection byE.bieneusigenotypes KB-1 and CHN6. Enterocytozoon bieneusiis the mainly pathologies or intestinal disorders that causes approximately 90% of reported cases of human microsporidiosis. To understand the prevalence and genotype distribution ofE.bieneusiin the Xinjiang Uygur Autonomous Region, China, 609 fecal samples were collected from children in kindergarten in Southern Xinjiang and screened for this pathogen by PCR and sequencing of the internal transcribed spacer (ITS). Thirty-six fecal samples (5.9%, 36/609) were positive forE.bieneusi, with the highest prevalence observed in children from Yopurga (17.5%, 11/63). Nine genotypes were identified, of which six were known (A, CHN6, D, EbpA, KB-1, and NIA1) and three were novel (CXJH1, CXJH2 and CXJH3). Genotype NIA1 was most prevalent (52.8%, 19/36), followed by genotypes D (16.7%, 6/36), A (8.3%, 3/36), and EbpA (8.3%, 3/36). The remaining five genotypes were detected in one sample each. Phylogenetic analysis revealed that theE.bieneusiisolates clustered into two groups, one consisting of six genotypes (Group 1: A, CXJH1, D, EbpA, KB-1, and NIA1) and another consisting of three genotypes (Group 2: CHN6, CXJH2, and CXJH3). Our results confirmed that infection ofE.bieneusiunusual dominant genotype NIA1 occurs in children in Xinjiang, China. Further epidemiological studies must be conducted to clarify potential sources ofE.bieneusiinfection in this area.