Occurrence and molecular characterization of Enterocytozoon bieneusi among long-tailed macaques (Macaca fascicularis) in Hainan Province: High genetic diversity and zoonotic potential

Abstract

Objective: Microsporidia have been rapidly emerging as pathogens in both immunocompromised and immunocompetent humans. Enterocytozoon bieneusi (E. bieneusi) is the most common microsporidial species found in human. E. bieneusi has also been found in a wide range of animals and is considered to be a potentially important zoonotic pathogen. The epidemiological and genetic characterization of E. bieneusi among long-tailed macaques [Macaca fascicularis (M. fascicularis) is not fully understood. Here, we conducted the first molecular epidemiological investigation of E. bieneusi among M. fascicularis in Hainan Province, the southernmost part of China. Methods: A total of 193 fecal specimens of M. fascicularis were collected from a breeding base housing non-human primates for experimental use in Hainan Province, China. E. bieneusi was identified and genotyped by nested PCR analysis of the internal transcribed spacer (ITS) region of the rRNA gene. Phylogenetic analysis was performed by constructing a neighboring-joining tree of the ITS gene sequences using MEGA6. Results: A total of 59 (30.6%) of the M. fascicularis were PCR-positive for E. bieneusi. All 59 samples were sequenced successfully and 16 ITS genotypes were identified. These included nine known genotypes: Type IV (n=19), D (n=11), CM1 (n=8), PigEBITS7 (n=4), Pongo2 (n=4), Peru 8 (n=3), Peru11 (n=1), WL21 (n=1) and CM2 (n=1). Additionally, seven novel genotypes named as HNM-I to HNM-VII (one each) were identified. Importantly, genotypes D, Type IV, Peru8, PigEBITS7, and Peru11, which were the predominant (38/59, 64.4%) genotypes identified among M. fascicularis in this study, are also well-known human-pathogenic genotypes. All the genotypes of E. bieneusi identified in this study, including the seven novel ones, belonged to zoonotic group 1. Conclusions: This is the first report of the identification of E. bieneusi in M. fascicularis in Hainan Province, China. The findings of numerous known human-pathogenic types and seven novel genotypes (HNM-I to HNM-VII) of E. bieneusi all belong to zoonotic group 1 indicate the possibility of transmission of this important pathogenic parasite between M. fascicularis and humans.

Keywords

• Enterocytozoon bieneusi; Genotype; ITS region; Macaca; Zoonotic