University of Waterloo scientists invent cheaper way to test E. coli in drinking water


Researchers at the University of Waterloo, in Ontario, Canada, have developed a faster and cheaper way for communities to test the presence of potentially dangerous Escherichia coli (E. coli) in their drinking water.

E. coli is a gram-negative, facultatively anaerobic, rod-shaped, coliform bacterium of the genus Escherichia, commonly found in the lower intestine of warm-blooded organisms (endotherms).

Some E. coli serotypes can cause serious food poisoning in a person.

While other existing tests cost approximately $70 and can take up to three days to provide the results, the new invention uses only paper strips similar to those used in litmus tests to generate results in less than three hours and at an affordable cost of 50 cents.

Waterloo Institute for Nanotechnology executive director Sushanta Mitra said: “This has the potential to allow routine, affordable water testing to help billions of people in the developing world avoid getting sick.”

The bottom of the paper strip is laced with sugar that starts dissolving once the paper is placed in water.

E. coli bacteria are attracted by the sugar trail and get trapped in the porous paper when they come in contact with it.

Water, as it enters the paper strip, carries the trapped E. coli into an area of the strip containing a mixture of chemicals, which react with the bacteria to turn the strip pinkish red, signifying a positive test.

Currently being refined by Glacierclean Technologies, the test can be used to enhance water safety in remote or rural areas of the developed world as well as help reduce testing costs for municipal treatment systems.