ABSTRACT
A modified adsorption-elution technique for concentration of enteric viruses from sewage and water samples was developed. The viruses in water were concentrated by negatively charged membrane filtration, eluted with 2.9% tryptose phosphate broth containing 6% glycine pH 9.0, and reconcentrated using centrifugation by a speedVac concentrator. The presence of poliovirus, hepatitis A virus (HAV) RNA, and rotavirus antigen was determined by cell culture isolation, nested polymerase chain reaction (nested PCR), and enzyme-linked immunosorbent assay (ELISA), respectively. A total of 100 sewage and water samples were collected from various sources in congested communities in Bangkok, concentrated and examined for those enteric viruses. Of 20 surface water samples from canals which located near sewage drains, 15% were positive for HAV RNA by nested PCR. Of 48 domestic sewage samples from man-holes of underground sewers, 8% were positive for rotavirus antigen by ELISA. Even though the samples were concentrated 256-2,000 fold, poliovirus was not found by isolation in cell culture.
Subject(s)
Animals , Antigens, Viral/analysis , Cell Line , Centrifugation , Enzyme-Linked Immunosorbent Assay , Filtration , Hepatovirus/isolation & purification , Humans , Macaca mulatta , Poliovirus/isolation & purification , Polymerase Chain Reaction , RNA, Viral/analysis , Rotavirus/immunology , Thailand , Tumor Cells, Cultured , Virus Cultivation , Water MicrobiologyABSTRACT
Safe water is essential for good health of humans. The contamination of water with infected fecal material is common in areas with poor standards of hygiene and sanitation. The determination of microbiological quality of water is essential. Simple routine testing of the bacteriological quality of drinking water is designed to detect the presence of coliform bacteria and virological assessment is to detect the presence of enteric viruses, especially hepatitis A virus (HAV). Therefore, this study attempted to determine the HAV and coliform bacteria contamination in drinking water and using water of a Chao Phya River community, Bangkok where crowded living conditions increase the risk of water-related diseases. 95 samples of drinking water and 75 samples of used water in containers were collected with sterile technique for determining HAV antigen by ELISA and coliform contamination by the Most Probable Number Technique (MPN). The results revealed that HAV and coliform contamination rates of drinking water were 25.26% and 64.21%, respectively. The rain water had the highest contamination (60.00% and 80.00%). Tap water was 23.73% for HAV (14/59 samples) and 64.41% for coliforms (38/59 samples) whereas running water had the least contamination (2.94% for HAV and 5.88% for coliforms). The contamination rates of used water were 10.69% for HAV and 68.67% for coliforms.