Identification of Blastocystis sp. subtypes from human using 18s rRNA in Northwest of Iran

Blastocystis sp. is an anaerobic parasite that lives in the digestive system of humans with a vast variety of non-human hosts as the zoonotic parasite. This study was carried out to identify subtypes and to investigate the genetic variation of Blastocystis sp. from human samples in Urmia, Tabriz & Maragheh cities Northwest of Iran. In this descriptive-cross sectional study, 300 human stools from Jan till Oct 2017 were randomly selected from treatment centers in North West of Iran. Based on microscopic observation, positive samples examined by DNA barcoding methods for detection of Blastocystis sp. subtypes and their sequences were analyzed. Out of 300 samples, 248(82.7%) cases were male and 52(17.3) were female. Of these, 20 samples diagnosed Blastocystis sp. positive with the microscopic method. 16 of them were examined by molecular method (PCR) and sequences analyses showed that 3 subtypes (STs) containing ST1, ST2, and ST3. There is a zoonotic cycle of this parasite in this studied area. By subtypes identifying of Blastocystis sp. in different hosts with distributed prevalence, it is possible to prevent the disease and complications from it and stop the transmission cycle.