Phylogenetic relationship of Blastocystis sp. STs based on SSU rRNA gene sequences. Clustal X and Mega 7 software were used to calculate genetic distance and build the phylogenetic tree. The phylogenetic tree was constructed using the maximum likelihood method, based on the evolutionary distances calculated by the Tamura-3 parameter model; all positions containing gaps and missing data were eliminated. Bootstrap values were obtained using 1,000 replicates. The blue and red fonts represent the known and novel sequences, respectively identified in this study.