Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 6 3 2011 09 15 43 51 EN MR Mahmoudi Department of Parasitology and Mycology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran AND Fasciolosis & Parasitic disease Center Research, Guilan University of Medical Sciences, Rasht, Iran AND Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran K Ashrafi Fasciolosis & Parasitic disease Center Research, Guilan University of Medical Sciences, Rasht, Iran H Abedinzadeh Tehran Province Water & Wastewater (TPWW), Tehran, Iran F Tahvildar-Bideruni Department of Parasitology and Mycology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran A Haghighi Department of Parasitology and Mycology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran M Bandehpour Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran and Department of Biotechnology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran N Taghipour Lailabadi Department of Parasitology and Mycology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran B Kazemi Department of Parasitology and Mycology, Faculty of Medicine, Shahid Beheshti University of MedicalSciences, Tehran, Iran AND Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran AND Department of Biotechnology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2015 10 03 Background: The protozoan parasites Cryptosporidium spp. and Giardia are known to occur widely in both raw and drinking waters. They are two of the causative agents of waterborne out-breaks of gastroenteritis throughout the world. In the present study, a PCR assay and FA were developed for detection of Cryptosporidium oocysts and Giardia cyst in environmental samples. Methods: We have detected Cryptosporidium spp. oocysts and Giardia cysts in seeded and un-seeded environmental water samples by PCR method. Water samples were spiked with oocysts (50, 100,300,500) and filtrated with a 1.2-µm pore size cellulose nitrate and follow by DNA extrac¬tion and purification by QIAamp DNA mini kit. Nested-PCR assay amplified an 850 bp fragment of 18s rRNA gene specific for Cryptosporidium and 435 bp fragment of glutamate dehydrogenase (GDH) target gene for Giardia. Also many river water from north of Iran, be checked by these methods. Results: Cryptosporidium and Giardia DNAs were detected in seeded water sample and Giardia was detected in all 5 water samples from river in north of Iran by nested- PCR and FA. Also in one river water sample, Cryptosporidium was detected. Conclusion: This protocol is effective for detection of these waterborne parasites in treated and untreated water samples. This study can also serve as a platform for further investigations and research water source in Iran. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/187 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/187/186