Which microorganisms commonly thrive in drinking water distribution systems and how might they impact human health?

Question

What will be an ideal response?

Answer 1

Answer: Despite sufficient chlorination of drinking water, biofilms persist on the walls of pipes in water distribution systems. The biofilms consist mostly of non-pathogenic bacteria, but can harbor opportunistic pathogens such as Naegleria, Acanthamoeba, Legionella, Pseudomonas, and Mycobacterium species. There are also large numbers of protists present that graze on (eat) the bacteria in the biofilm. Legionella, Pseudomonas, and Mycobacterium species can live inside these protists, increasing their ability to persist in the environment. Although these organisms are present in drinking water systems, they are usually opportunistic pathogens and thus may not affect the health of people with normal immune systems. The impact of these organisms and how they might be distributed through showerheads and other mechanisms is an area of current research.