occurrence of viruses and p ro tozoan parasi tes in surface, ground and treated water in the ci ty of mashhad, iran

a research plan was developed to evaluate the occurrence of enteroviruses, giardia cysts and cryptosporidium oocysts in thirty-five different sites in the city of mashhad, iran. the occurrence of these pathogenic microorganisms was evaluated to investigate a possible health risk in the communities. for the detection of enteroviruses in water samples, the conventional method of cell culture, using buffalo green monkey (bgm) cell line, was used. the minimum sample volume for viruses was 500 liters, collected using a positively charged mk cartridge filter, eluted with beef extract and concentrated by organic flocculation. the method of detection for cysts and oocysts relied on microscopic observation of water samples by the immunofluorescence assay (ifa). for this study, water samples were collected using a cartridge filter, eluted by washing the filter using a detergentbased medium, concentrated by centrifugation, clarified by a percoll-sucrose density gradient, stained by an indirect fluorescent antibody, and examined by epifluorescence microscopy. a total of seventy surface, ground or treated water samples were collected from 35 different sites in the metropolitan city of mashhad. thirty-five samples were assayed for the presence of enteroviruses by cell culture and 35 samples were assayed by ifa technique for the detection of cysts and oocysts. two surface water samples tested positive for virus presence and three surface water samples tested positive for giardia cysts. based on the results of this research project, no microbial contamination of finished water was documented, suggesting proper treatment of surface water at the time of sampling.