Molecular evidence for zoonotic transmission of Blastocystis subtypes in Kurdistan province, West of Iran.

Blastocystis sp. is one of the most prevalent human parasites with a vast variety of non-human hosts. The aim of the present study was to determine the subtype distribution of Blastocystis in humans and trace the route of transmission by molecular data and phylogenetic analysis. Stool samples were collected from patients who referred to 14 medical laboratories in Kurdistan, Iran. All the samples were examined using the direct wet mount and formalinether concentration techniques. DNA extraction was carried out for 30 microscopically positive isolates and 33 negative samples. DNA amplification and subtype identification were also performed using the barcoding method and sequencing techniques. Of 1383 stool samples, 239 (17.3%) were infected with Blastocystis sp. Out of the 24 sequenced isolates, two (8.3%), six (25%), and 16 (66.6 %) belonged to the ST1, ST2, and ST3 subtypes, respectively. Bioinformatics analysis indicated that all the isolates were genetically similar to animal isolates. Blastocystis sp. was very common and ST1, ST2, and ST3 subtypes were prevalent in the study population. Bioinformatics analysis suggests that zoonotic transmission plays an important role in Blastocystis sp. distribution in Kurdistan province.