Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 8 4 2013 12 15 601 607 EN Mohhammed Asadpour Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran. Gholamreza Razmi Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran. Gholamreza Mohhammadi Department of Clinical Science, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran. Abolghasen Naghibi Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran. 2015 10 14   Background: Cryptosporidium parvum is a zoonotic pathogen transmissible from a variety of animals to humans and is a considerable public health concern. Dairy cattle have been identified in numerous reports as a major source of environmen-tal contamination with this pathogen. The aim of study was to detect and isolate the Cryptosporidium spp. from fecal samples of naturally infected pre-wean calves in the Mashhad area Methods: Overall, 300 fecal specimens from 1 to 30 days pre-weaned calves were collected from 10 farms in the Mashhad area the capital center of the Khorasan Razavi Province, Iran and microscopically examined for Cryptosporidium spp. All infected samples were also analyzed using nested –PCR. A polymerase chain reac-tion (PCR)-restriction fragment length polymorphism (RFLP) analysis of the small-subunit (SSU) rRNA gene was also used to detect and identify Cryptosporid-ium spp. in PCR- positive samples. Results: Eighty five (28.3%) of the specimens were positive for Cryptosporidium spp. The prevalence of Cryptosporidium spp. in 8-14 days old and diarrheic calves were significantly higher than other groups. Restriction digestion of the PCR products by SspI, VspI restriction enzymes and sequence analysis revealed the presence of C. parvum bovine genotype in all isolates. Conclusions: Our results suggest that pre-weaned calves are likely to be an important reservoir of zoonotic C. parvum. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/449 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/449/519