en Parasitologiy Parasitologiy پژوهشي Research <div> <p><strong>Introduction: </strong>The protozoan parasite, <em>Cryptosporidium</em> Spp., widely spreads in both raw and drinking waters. It is the causative agents of waterborne diarrhea and gastroenteritis in the world. In the present study, a molecular assay was used for the detection and quantification of <em>Cryptosporidium</em> oocysts in environmental water samples.</p> <p><strong>Materials and methods:</strong> Thirty surface water samples were collected from Rasht City rivers and lagoons during 2009-2010. The samples were analysed for <em>Cryptosporidium</em> oocysts using Real Time PCR method. Samples were filtrated through a 1.2&micro;m pore size cellulose nitrate membrane filter and then purified and quantified by Real-time PCR technique.</p> <p><strong>Results:</strong> <em>Cryptosporidium</em> oocysts were found in 19 of 30 the samples. Oocyst concentration was ranging from 0.007 to 27 oocysts per liter of the examined waters.</p> <p><strong>Conclusion:</strong> The present study showed that the investigated water supplies were contaminated by <em>Cryptosporidium </em>oocyst. This study indicated that in this level of oocysts there is a potential risk of waterborne cryptosporidiosis due to direct or indirect consumption of these waters by humans and animals. Real-time PCR is a technique that provides high sensitivity for detection quantitative purposes.</p> </div> Cryptosporidium spp., Water, Iran, Real-time PCR 42 47 http://jbrms.medilam.ac.ir/browse.php?a_code=A-10-58-2&slc_lang=en&sid=1 Mohammad-Reza Mahmoudi amirzaeii@yahoo.com 10031947532846002588 10031947532846002588 No Department of Parasitology, Faculty of Medicine, Guilan University of Medical Sciences, Rasht, Iran Mojgan Bandepour amirzaeii@yahoo.com 10031947532846002589 10031947532846002589 No Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Bahram Kazemi amirzaeii@yahoo.com 10031947532846002590 10031947532846002590 No Department of Biotechnology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Asad Mirzaei amirzaeii@yahoo.com 10031947532846002591 10031947532846002591 Yes Department of Parasitology, Faculty of Allied Medical Sciences, Ilam University of Medical Sciences, Ilam, Iran