Image: New test finds bacteria in liquids and indicates their presence by changing color (Photo courtesy of Georgia Kirkos/McMaster University)
Bacteriophages, the most widespread form of life on Earth, specialize in attacking and destroying specific types of bacteria. Its natural ability to fight bacteria has long been used to treat infections. Now researchers have developed a new test that uses harmless bacteriophages to detect disease-causing bacteria in fluids. This test allows even untrained users to identify bacterial contamination in liquids using a biogel that changes color when exposed to bacteria such as E. coli listeria and other common pathogens.
The test, developed by a team of engineers and biochemists at McMaster University (Hamilton, Ontario, Canada), uses bacteriophages embedded in a gel to detect bacteria in fluid samples, including urine, even at low concentrations. In the test, the bacteriophages target and attack specific bacteria in the sample. When destroyed, the bacteria release small amounts of intracellular material that the test can detect, causing the gel to change color. If no bacteria are present, the color remains unchanged. The process only takes a few hours to provide results, significantly faster than traditional laboratory cultures, which can take up to two days. The proof, detailed in an article published in Advanced materialsis part of a broader effort by researchers to develop simple technologies accessible to consumers, clinicians and industry.
The team had previously worked to create a portable library of tests that used phages to fight antibiotic-resistant infections. To validate the new test, the researchers used urine samples from Hamilton Health Sciences patients, and the results were consistent with results from traditional laboratory methods. This new test can be customized for any bacteria using specific bacteriophages and DNA probes targeting microbes such as Listeria and Salmonella. The ability to analyze the contamination of complex fluids such as blood and urine is particularly challenging, and the simplicity and reliability of this new test make it a valuable tool. The researchers hope to work with commercial partners to bring this innovation to market.
“Today, people who suspect they may have a urinary tract infection have to go to the doctor and sometimes wait days for the result. This technology would make it very easy for people to get tested at home and get a result within hours,” said corresponding author Tohid Didar, an associate professor of mechanical and biomedical engineering who holds the Canada Research Chair in Nanobiomaterials.
