Phylogenetic relationship of Enterocytozoon bieneusi groups. The relationships between E. bieneusi genotypes identified in this study and other known genotypes deposited in the genbank were inferred by a neighbor-joining analysis of ITS sequences based on genetic distance by the Kimura-2-parameter model. The numbers on the branches represent percent bootstrapping values from 1000 replicates (only bootstrap values >50% are shown). Each sequence is identified by its accession number, genotype designation, and host origin. Genotypes with black triangles and open triangle are novel and known genotypes identified in this study, respectively.