Zoonotic potential of Enterocytozoon bieneusi among children in rural communities in Thailand

Enterocytozoon bieneusi is a common opportunistic intestinal pathogen worldwide. Genotype distribution of E. bieneusi differs by geography and host immunity. In order to investigate the prevalence, genotype characteristics, and host specificity of E. bieneusi in the community, we conducted a preliminary cross-sectional study among children in Western and Northern Thailand. Seventy-eight (78) and 102 stool samples were collected; the prevalence of E. bieneusi was 3.8% and 2.9% by nested PCR in Western and Northern Thailand, respectively. Three genotypes were identified: Genotype D predominated, followed by EbpC, and then novel genotype ETMK1. The first two genotypes have zoonotic potential. Analysis of the genetic proximity of the E. bieneusi ITS sequences from our study, compared with those published in genetic databases, showed that all positive samples were classified into Group 1, the largest group consisting of various host specificity. The present study demonstrates the possible zoonotic transmission of E. bieneusi in rural communities in Thailand. A large-scale investigation of both human and animal samples, as well as improvements in the available phylogenetic tools, will be required to elucidate transmission routes of E. bieneusi in this area.