Molecular phylogenetic identification of Blastocystis sp. isolated from humans in the Northwest of Iran

Blastocystis sp. is a common parasite of humans with a vast variety of nonhuman hosts and global distribution. Based on molecular methods, distinct subtypes are isolated from different hosts. In this study, we detected human-isolated Blastocystis subtypes in the northwestern of Iran.

A total of 600 stool samples referred to health centers in Urmia and Maragheh cities in the northwest of Iran was randomly collected and examined using direct wet mount, formalin-ether concentration, a modified version of the Ziehl–Neelsen staining technique for the detection of parasitological items and using barcoding method (18S rRNA gene) for the molecular survey.

From 600 samples studied, 496 (82.7%) and 104 (17.3%) were male and female, respectively. Three subtypes, including ST1, ST2 and ST3, were identified from collected samples, and the frequent subtypes were ST3, ST1, and ST2, respectively.

While genetic similarity of Blastocystis isolated from human and animal did not show in this region, the zoonotic cycle of this parasite, probably by fecal contamination, exists in the study area. By identifying Blastocystis subtypes, it is possible to prevent the transmission and related complications.