Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 9 1 2014 03 15 79 89 EN Salman Ghaffari Dept. of Parasitology and Mycology, School of Medicine, Babol University of Medical Sciences, Babol, Iran. Narges Kalantari Cellular and Molecular Biology Research Centre, Babol University of Medical , Babol, Iran. 2015 10 14   Background: Cryptosporidium species are important cause of diarrheal diseases in both developing and developed countries. This study aimed to compare the perfor-mance of several molecular methods for identification of Cryptosporidium species, and to detect genetic variation among each of these species isolated from Iran, Ma-lawi, Nigeria, Vietnam and the United Kingdom. Methods: The oocysts DNA samples were derived from 106 Cryptosporidium posi-tive feces. Polymerase chain reaction, PCR- restriction fragment length polymor-phism and DNA sequence analysis of the 18S rRNA and the Cryptosporidium oo-cysts wall protein genes; PCR and DNA sequence analysis of a fragment of 70 kDa heat shock protein and 60 kDa glycoprotein genes were carried out. Results: Based on these analysis, three species of Cryptosporidium including C. homi-nis, C. parvum and C. meleagridis, and both C. hominis and C. parvum were found in Iranian and the UK samples, respectively. Also, three C. hominis (Ib, Ib3& Id) and three C. parvum (IIa, IIc & IId) subtypes were identified by sequence analysis of the GP60 gene. Of these, C. hominis Ib was predominant and interestingly, one subgen-otype (C. hominis Ib A10G2) accounted for the majority of the samples. Conclusion: The current study demonstrates the complex subtypes of Cryptosporid-ium isolates in both developing and developed countries. This is the first report of C. parvum IId subgenotype and three new subtypes of C. parvum IIa in the UK, a new subtype of C. hominis Id from Malawi; and the first multi-locus study of three species of Cryptosporidium in human from Iran. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/430 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/430/308