Clinical and Public Health Microbiology

Cheap, Fast Test for E. coli in Drinking Water Almost Ready for Market

A test for E. coli in drinking water that costs 50 cents per test and gives results in 30-180 minutes has been developed by researchers at the University of Waterloo in Ontario, Canada, and may be on the market in as little as nine months.

Sushanta Mitra and his colleagues Naga Siva Kumar Gunda and Saumyadeb Dasgupta say their test will allow people in developing countries and remote or rural areas of the developed world to test their water supplies and avoid illness, and will also reduce testing costs for municipal water treatment systems.

The test uses paper strips, similar to litmus test strips.  The bottom of the strips contain sugar, which dissolves in water and leaves a trail.  E. coli bacteria are attracted to the trail and get trapped in the porous paper when they touch it.  The trapped bacteria are carried into an area of the strip containing chemicals that turn pinkish red when they come in contact with E. coli, signifying a positive result.  If levels of contamination are high, the strip turns pink in 30 minutes.  Low levels of contamination can take up to 180 minutes, but the researchers are working on reducing testing times.

Mitra and Gunda co-founded a company called Glacierclean, which already sells mobile water test kits for E. coli that cost about $5 per test.  They hope to get their DipTest strips on the market in nine months or less.

“Simple ideas create paradigm shifts in technology and this is a simple, frugal innovation,” said Mitra.

For more information, got to the September 6 issue of PLOS ONE;