Molecular survey of Enterocytozoon bieneusi in a Japanese porcine population.

Enterocytozoon bieneusi is an emerging and clinically significant enteric human pathogen that is mainly associated with chronic diarrhea. It has been identified in a variety of wild, domestic, and companion mammals and birds. This pathogen is genetically diverse and is composed of over 80 host-specific and zoonotic genotypes. Pigs are considered one of the main reservoirs of this pathogen given its high reported prevalence in pigs, and pigs may harbor zoonotic and pig-specific genotypes. Therefore, genotyping of isolates from pigs and other animals is essential for the control of E. bieneusi infection. In Japan, it remains unclear whether this pathogen is present in the porcine population. In the present study, we examined 30 fecal samples from pigs reared on 6 farms in western Japan. Ten pigs (33%) were found to be positive when assessed by polymerase chain reaction. The genotypes were varied and were found to be animal specific (EbpA, H, PigEBITS5) and zoonotic (D, EbpC) in genotype. The observation that pigs in Japan appear to be infected with zoonotic and animal genotypes of E. bieneusi raises questions about the prevalence of this infection among the human population in Japan.