To rapidly detect the presence of E. coli in drinking water, food scientists at Cornell University, US now can employ a bacteriophage, a genetically engineered virus, in a test used in hard-to-reach areas around the world.
Rather than sending water samples to laboratories and waiting days for results, this new test can be administered locally to obtain answers within hours.
The bacteriophage T7NLC carries a gene for an enzyme NLuc luciferase. The luciferase is fused to a carbohydrate (sugar) binder, so that when the bacteriophage finds the E. coli in water, an infection starts, and the fusion enzyme is made. When released, the enzyme sticks to cellulose fibers and begins to luminesce.
After the bacteriophage binds to the E. coli, the phage shoots its DNA into the bacteria. The bacteriophage then breaks open the bacterium, releasing the enzyme as well as additional phages to attack other E. coli.
According to the team, phage-based detection technologies have the potential to rapidly determine if a water source is safe to drink, a result that serves to immediately improve the quality of life of those in the community through the prevention of disease.