Michigan Technological University scientists have come up with a way to make a strain of E. coli glow under fluorescent light, a technique that may one day help track down all sorts of pathogens, and even prove beneficial in fight against breast cancer.
Associate Professor of Chemistry Haiying Liu, who led the research project, points out that E. coli bacteria are naturally found in animal intestines and are usually harmless, but when virulent strains contaminate food, they can cause serious illness and even death.
Liu's trick takes advantage of E.coli's affinity for the sugar mannose.
During the study, the research team attached mannose molecules to specially engineered fluorescent polymers, and stirred them into a container of water swimming with E. coli.
The researchers said that microscopic hairs on the bacteria, called pili, hooked onto the mannose molecules like Velcro, effectively coating the bacteria with the polymers.
They later shined white light onto E. coli colonies growing in the solution, and the bugs lit up like blue fireflies.
"They became very colorful and easy to see under a microscope," said Liu.
The researcher says that this approach may help identify a wide array of pathogens by mixing and matching from a library of different sugars and polymers, which fluoresce different colours under different frequencies of light.
If blue means E. coli, they add, fuchsia may one day mean influenza.
Liu is adapting the technique to combat breast cancer also. In place of mannose, he plans to link the fluorescent polymers to a peptide that homes in on cancer cells.
He says that upon introduction to the vascular system, the polymers would travel through the body, stick to tumour cells, and then illuminated by a type of infrared light that shines through human tissue.
The researcher says that the glowing polymers would provide a beacon to pinpoint the location of the malignant cells, and allow surgeons to easily identify and remove malignant cells while minimizing damage to healthy tissue.
An article on the team's work on E. coli has been published in the journal Chemistry.