Quality assessment of supplied drinking water in Jaipur city, India, using PCR-based approach

Jaipur city is one of the largest and fast developing cities of state Rajasthan, India. Majority of population in the city depends on piped water supplies for drinking and other domestic purposes. However, limited water resources, rapid industrialization and urbanization had resulted in increased pressure on water availability which in turn has led to deterioration of quality of drinking water. Microbial pathogens are one of the major health risks associated with water. With microorganisms, a primary cause for the occurrence of infectious diseases, the concentrations of harmful bacterial cells should be routinely monitored to maintain microbiological quality control of drinking water. The specific aim of the present study was to assess the microbiological and physicochemical quality of drinking water supplied in Jaipur. Water samples from twelve areas were collected and evaluated for physicochemical contaminants such as pH, electrical conductivity, fluoride, iron, nitrate, residual chlorine, total dissolved solids, total hardness and turbidity. The samples were also evaluated for eight most commonly found bacterial pathogens. Pathogenic bacteria were detected using polymerase chain reaction-based assays. Majority of parameters except few were found to be within bureau of Indian standards safety limits. Of all the bacteria tested, Pseudomonas was the most prominent bacteria and was detected in all locations. Escherichia coli, Aeromonas and Shigella were detected in three of the twelve locations, whereas Campylobacter was detected in two of the locations. Vibrio, Salmonella and Arcobacter were not detected in any of the locations. This approach was rapid, specific and sensitive. This study shows that water quality standards based on the occurrence of specific pathogens enumerated with PCR-based assays could serve as a method of evaluating the biological quality of water. Also, this study confirms the presence of these pathogenic bacteria in drinking water which may pose a serious health risk to consumers. This suggests that proper management of water resources (surface and groundwater) and regular water monitoring are needed. Also water utility operations should be such that quality is not impaired during transmission, storage and distribution of the municipal tap water to the consumer.