genetic characterization of cryptosporidium spp. among patients with gastrointestinal complaints referred to clinical laboratories of tehran, iran

background : cryptosporidium, an intracellular protozean parasite, is among the major causative agents of gastroenteritis disorders in humans and also causing water-borne and food-borne outbreaks of diarrheal diseases. this study investigated subtypes of cryptosporidium in patients with gastrointestinal complaints in tehran, iran. methods: a total of 1685 fecal samples were collected from patients with gastrointestinal complaints who had been referred to clinical laboratories tehran, iran. the primary diagnosis was established by detection of oocysts using the modified ziehl-neelsen acid-fast staining method and following that, the positive microscopically samples were selected for sequence analysis of partial 60 kda glycoprotein (gp60) gene. results: out of 1685 collected samples, 7 (0.4 %) were positive for cryptosporidium oocysts.  sequences analysis of gp60 gene in seven cryptosporidium isolates revealed that, two subtype families were identified, iia and iid. five (of 7) isolates belonged to the subtype family iia and remaining 2 isolates belonged to iid. three sub-types were recognized within the subtype family iia including iiaa16g2r1 (3/5), iiaa17g1r1 (2/5), while iida17g1d was the only subtype within iid subtype family. conclusion: the predominance of zoonotic subtype families of c. parvum species (iia, iid) in this study highlights the importance of zoonotic transmission of cryptosporidiosis in the country.