Scientists in the US have been conducting studies that they hope will help them find ways to target four potentially deadly pathogens that exist in drinking water.
The team – based at Virginia Tech – used new cutting-edge laboratory equipment to see how many dangerous microbes exist in the tap water used in houses and hospitals.
They were particularly keen to focus on Legionella – which causes Legionnaires' disease, Mycobacterium avium complex and Pseudomonas aeruginosa. The latter is the leading cause of hospital infections and is a big concern for people with weaker immune systems.
Documenting their findings in the American Chemical Society journal, Environmental Science and Technology, the researchers stated their main intention was to discover if harmless microbes could be used to combat these pathogens.
Amy Pruden, a professor of civil and environmental engineering, explained the importance of these latest studies.
"We have new tools – the next generation DNA-sequencing tools, which have just come online in the last five years," she remarked.
"They are providing unprecedented information about microbes in all sorts of environments, including 'clean' drinking water. These tools have really surprised us by showing us the numbers and diversity of microbes. There can be thousands of different species of bacteria in a household water supply."
Ms Pruden said these harmful bacteria are "opportunistic" and we need to improve our understanding of these microbes if we are to stand a chance of fighting water-borne diseases.
She added that attempts to disinfect plumbing systems could be killing harmless, potentially helpful microbes.
Earlier this year, researchers at the University of Sheffield in the UK conducted similar experiments that showed high levels of "harmless" bacteria can also be problematic.
Although these do not cause people to fall ill, they can sometimes provide an environment for other more dangerous microbes to develop.
Leader of the studies Professor Catherine Biggs said the DNA testing being developed in Sheffield could provide a faster and more advanced system for water companies looking to treat their supplies in the future.