en Infectious disease (Molecular and Cellular aspects) Infectious disease (Molecular and Cellular aspects) Original Article Original Article <p><em>Cryptosporidium</em> is one of the most common causes of childhood diarrhea in developing countries. The aim of this randomized pilot study was to detect and characterize infective species and determine the genotypes of <em>Cryptosporidium</em> parasites in pediatric patients suffering from diarrhea in North West of Iran. A total of 113 fecal samples were collected from diarrheic children hospitalized in Tabriz Pediatric Hospital. The amplification of small subunit ribosomal RNA gene was performed using a nested polymerase chain reaction protocol and its products were digested using two restriction enzymes for <em>Cryptosporidium</em> species and genotype differentiation. <em>Cryptosporidium </em>oocysts were found in 2 (1.76%) children with diarrhea and restriction pattern revealed the presence of <em>C.parvum </em>bovine genotype in both positive fecal samples. The findings indicate that <em>Cryptosporidium parvum </em>is responsible for cryptosporidiosis in children in the study region and probably zoonotic transmission is the predominant route of parasite transmission.</p> Child, Cryptosporidium, genotype, PCR, Iran 235 239 http://ijmcmed.org/browse.php?a_code=A-10-532-1&slc_lang=en&sid=1 Behroz Mahdavi poor Behroz.mahdavi@gmail.com 10031947532846006043 10031947532846006043 Yes Department of Laboratory Science, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran. Mohammad Asgharzadeh Asgharzadehmo@yahoo.com 10031947532846006044 10031947532846006044 No Biotechnology Research Center and Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran. Esmaeel Fallah Fallahe@tbzmed.ac.ir 10031947532846006045 10031947532846006045 No Department of Parasitology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. Kareem Hatam-Nahavandi Karim.hatam@gmail.com 10031947532846006046 10031947532846006046 No Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Jalil Rashedi Rashedijalil@gmail.com 10031947532846006047 10031947532846006047 No Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran. Abdolhossein Dalimi dalimi_a@modares.ac.ir 10031947532846006048 10031947532846006048 No Department of Medical Parasitology, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran.