Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 6 4 2011 12 15 41 45 EN N Taghipour Dept. of Parasitology, Shahid Beheshti University of Medical Sciences, Tehran, Iran E Nazemalhosseini- Mojarad Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Iran A Haghighi Dept. of Parasitology, Shahid Beheshti University of Medical Sciences, Tehran, Iran A Haghighi Dept. of Parasitology, Shahid Beheshti University of Medical Sciences, Tehran, Iran M Rostami- Nejad Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Iran S Romani Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Iran A Keshavarz Dept. of Parasitology, Shahid Beheshti University of Medical Sciences, Tehran, Iran M Alebouyeh Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Iran MR Zali Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Iran 2015 10 03 Background: Cryptosporidium is a worldwide protozoan parasite and one of the most common causes of infection and diarrhea in humans and cattle. The aim of the present study was determina­tion of subtypes of Cryptosporidium among children with diarrhea in Tehran by se­quence analysis of the highly polymorphic 60-kDa glycoprotein (GP60) gene. Methods: Fecal samples were collected from 794 diarrheic children. Initial identification of Crypto­spo­ridium was carried out on stool samples by Ziehl-Neelsen acid-fast staining method. DNA was extracted from positive microscopically samples and Cryptosporidium genotypes and subtypes were determined, accordingly. Results: Out of 794 collected samples, 19 (2.40 %) were positive for Cryptosporidium oocysts. Sequences analysis of GP60 gene showed that 17 (89.47 %) of the positive isolates were Crypto­spori­dium parvum and 2 (10.52 %) were C. hominis. All subtypes of C. parvum isolates belonged to allele families IIa (6/17) and IId (11/17). The most common allele in all 17 isolates belonged to IId A20G1a (41.18%). A22G1 (IF) subtype was detected in two C. hominis isolates of the chil­dren. Conclusion: The predominancy of C. parvum species (specially, IId A20G1a sub­type) in current study underlines the importance of zoonotic Cryptosporidium transmission in Iran. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/203 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/203/202