development of sensitive detection of cryptosporidium and giardia from surface water in iran

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. r esults : 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.