Surveillance of enteric viruses and coliphages in a tropical urban catchment

• Published in: Water research (Oxford) Vol. 58; pp. 122 - 131
• Main Authors: Rezaeinejad, S., Vergara, G.G.R.V., Woo, C.H., Lim, T.T., Sobsey, M.D., Gin, K.Y.H.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-07-2014; Elsevier
• Subjects: Adenoviridae - genetics; Adenoviridae - isolation & purification; Applied sciences; Bacteria; Catchments; Coliphages; Coliphages - genetics; Coliphages - isolation & purification; Continental surface waters; Enteric viruses; Enterovirus - genetics; Enterovirus - isolation & purification; Environmental Monitoring; Exact sciences and technology; Fresh Water - virology; Natural water pollution; Norovirus; Norovirus - genetics; Norovirus - isolation & purification; Pollution; Polymerase Chain Reaction; Quantitative PCR; Recreation; Recreational water quality; Reoviridae; Rotavirus; Rotavirus - genetics; Rotavirus - isolation & purification; Samples; Sampling; Seasons; Singapore; Statistical analysis; Statistical methods; Tropical Climate; Urban catchment; Urban Renewal; Viruses; Water Microbiology; Water Quality; Water treatment and pollution; Asia; Singapore; Recreational water quality; Coliphages; Urban catchment; Quantitative PCR; Enteric viruses; Adenoviridae; Norovirus; Microbiology; Picornaviridae; Tropical zone; Enterovirus; Urban area; Reoviridae; Pathogenic; Watershed; Biological contamination; Rotavirus; Coliphage; Virus; Polymerase chain reaction; Water tank; Gene amplification; Astrovirus; Surveillance; Water quality; Molecular biology; Bathing water; Phage
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2014.03.051

An assessment of the occurrence and concentration of enteric viruses and coliphages was carried out in highly urbanized catchment waters in the tropical city-state of Singapore. Target enteric viruses in this study were noroviruses, adenoviruses, astroviruses and rotaviruses. In total, 65 water samples were collected from canals and the reservoir of the Marina catchment on a monthly basis over a period of a year. Quantitative PCR (qPCR) and single agar layer plaque assay (SAL) were used to enumerate target enteric viruses and coliphages in water samples, respectively. The most prevalent pathogen were noroviruses, detected in 37 samples (57%), particularly norovirus genogroup II (48%), with a mean concentration of 3.7 × 102 gene copies per liter. Rotavirus was the second most prevalent virus (40%) with a mean concentration of 2.5 × 102 GC/L. The mean concentrations of somatic and male-specific coliphages were 2.2 × 102 and 1.1 × 102 PFU/100 ml, respectively. The occurrence and concentration of each target virus and the ratio of somatic to male-specific coliphages varied at different sampling sites in the catchment. For sampling sites with higher frequency of occurrence and concentration of viruses, the ratio of somatic to male-specific coliphages was generally much lower than other sampling sites with lower incidences of enteric viruses. Overall, higher statistical correlation was observed between target enteric viruses than between enteric viruses and coliphages. However, male-specific coliphages were positively correlated with norovirus concentrations. A multi-level integrated surveillance system, which comprises the monitoring of bacterial indicators, coliphages and selected enteric viruses, could help to meet recreational and surface water quality criteria in a complex urbanized catchment.
•Enteric viruses and coliphages were monitored in a tropical urban catchment.•The most prevalent and most abundant enteric virus was norovirus.•Noroviruses were positively correlated with male-specific coliphages.•Coliphage ratio was low where enteric viruses were frequently detected.•Coliphage ratio was high where enteric viruses were seldom detected.