Some carbohydrates act as a “fingerprint” or marker for each cell. These markers allow cells to recognize and talk to each other, which is critical for all aspects of cell development and cell-to-cell interaction. Importantly, carbohydrate markers allow the body to discriminate between substances that belong to the body from those that are foreign in order to determine the appropriate immune response required. Further protection against foreign material is provided by protective layers of mucus at entry points to the body such as the nose, throat and lungs. These layers are derived from carbohydrates. Many disease-causing bacteria are able to attach to, and infect cells, by binding to these carbohydrates. Alicia Lammerts van Bueren is studying how enzymes called glycoside hydrolases enable bacteria to infect human cells and hide from the body’s immune system. Her specific focus is on a glycoside hydrolase found on the surface of both Streptococcus pneumonie, which is the leading cause of pneumonia and bacterial meningitis, and Streptococcus pyogenes, which causes strep throat, necrotizing fasciitis and toxic shock. All these diseases can be fatal if left untreated. Alicia’s research into the carbohydrate binding function of these enzymes may explain how these bacteria cause disease in humans, and potentially lead to new drugs or vaccines to treat bacterial infections, which is particularly important given the rise of antibiotic resistance to streptococcal infections.