Infectious Aromas

            If you learned anything from grade eight health class it should have been sweat stinks. Well, not the sweat really, but the bacteria that thrive on it. The truth is, all bacteria stink, or at least smell. The same way you and I produce odourous byproducts now and then, bacteria too take in food and expel smelly waste.

            Similar to you and your college roommates, not all bacteria smell the same. In fact, each species and strain has a signature bouquet. This is because of differences in the nutrients each bacteria takes up, and the subtle differences in how they each process that food.

            In the lab we sometimes use to our advantage the fact that some bacterial cultures smell like smelly feet, while others are more reminiscent of sun-bathed pumpkins. Just by smelling a culture flask or plate, I can tell whether my experiment is pristine or compromised by contamination. Although this helps tell me if I’ve wasted another week of my life, a group led by Ken Suslick of the University of Illinois is using the same principles to develop potentially lifesaving technology.

            In his research, Dr. Suslick has developed arrays of chemically-sensitive dyes to detect low levels of air-born chemicals. These dyes react with a range of compounds and change colour based on a variety of chemical characteristics. So where one chemical might cause a reaction that makes a dye turn blue, a different chemical might cause the same dye to turn pink. Dr. Suslick’s group has developed a printed grid of different dyes that react differently to each chemical. When exposed to a specific chemical, the grid becomes a colourful fingerprint of its reactivities.

            So how does this technology help in a medical setting? Like we established before, each bacteria has a different scent, and these scents are made up of chemical compounds. This means that each bacteria has a different coloured scent fingerprint detected by the dye matrix. By exposing the grid to a sample of the bacteria this test can be used to identify infectious organisms in a matter of hours, a process that could take days by traditional techniques. In fact, the accuracy of this method is so high that it can even be used to tell antibiotic resistant strains and garden-variety strains apart.

            Time matters when an unknown bacteria has set up shop in your body. This technology provides a colourful solution for a quick diagnosis.

Learn more in the the original research paper