Colonization of opportunistic bacteria within distribution system

The opportunistic bacteria including P.aeruginosa are ubiquitous to a wide variety of aquatic environments including drinking water distribution systems. Concern over the survival and spread of opportunistic pathogens in public drinking water supplies has been expressed in recent years because of the public health risk associated with their presence in properly treated water. A municipal drinking water distribution system in Neemuch was monitored over a 12 month period to investigate population shifts of opportunistic bacteria at various sampling sites. Data generated during this study indicated that samples collected from storage reservoir, DS1, DS2 and end points contained P.aeruginosa in substantial amounts significantly higher than the health standards (P<0.05). However, Acinetobacter, Aeromonas, Moraxella and Flavobacterium were detected in negligible amounts with lower isolation rate. Differences in the concentration of opportunistic bacteria among the four sampling sites; Dam, Storage Reservoir, Distribution System and Point of use were significant throughout the year (P<0.05), except between the two sampling sites; DS1 and DS2 within the distribution system. Reductions in cell counts and isolation rate of opportunistic bacteria during the treatment method from surface raw water to finished water reflected an improvement in its trophic status, indicating that the treatment practices principally fulfilled their function. However, their presence in samples after chlorine disinfection during distribution presents potential threat to Neemuch community. Collectively, our results show the need to develop best management practices for municipal water to control bacterial regrowth and deterioration of water before it is utilized at the point of consumption.