Currently, there is no way to specifically and accurately image small numbers of bacteria in vivo.  Today's method commonly consists of CT imaging, which shows tissue damage.  The problem is that it is hard to distinguish between bacterial infections and other types of disease that cause tissue damage.  When bacterial infections are not detected early enough, they can become extremely hard to treat.

Biomedical Engineering Associate Professor Niren Murthy has been working on a new method, consisting of placing an agent inside of the bacteria which can be used for imaging.  "We think the big advantage of the maltodextrin transporter, which is what we are targeting, is that the maltodextrin-based imaging probes are internalised by bacteria at a very rapid rate, so you can deliver very high concentrations," he says.  Maltodextrin is a sugar-like molecule that is actively transported into bacterial, but not mammalian cells, giving the bacteria energy.  Researchers can then detect  which bacteria have internalised the maltodextrin.  Additionally, gut and dead bacteria do not absorb the maltodextrin.

Presently, there are still some limitations, such as only bacteria near the skin's surface can be detected. "What we are doing right now is to make MDPs that image bacteria by positron emission tomography - that will eventually overcome this problem," explains Murthy.

Murthy received his Ph.D. from the University of Washington and then served as a Postdoctoral Fellow at the University of California at Berkeley before joining Georgia Tech.  His research focuses on new materials for the delivery of biotherapeutics.