Researchers develop probe to detect staph bacteria

A research team at the University of Iowa created a probe that is able to identify Staphylococcus bacteria before symptoms appear, according to a paper published on Saturday in Nature Medicine.

The noninvasive chemical probe is able to detect a common species of staph bacteria in the body. The probe targets Staphylococcus aureus, a strain of bacteria that infects half a million people annually in the U.S. and kills 20,000 each year.

"We've come up with a new way to detect staph bacteria that takes less time than current diagnostic approaches," James McNamara, the corresponding author of the paper, said. "It builds on technology that's been around a long time, but with an important twist that allows our probe to be more specific and to last longer."

The synthetic probe includes a molecule that gives off light under certain conditions and another molecule that blocks the light. When staph bacteria come into contact with the particles, the pathogen separates the light-emitting molecule from the light-blocking molecule. This allows doctors to see the light-emitting molecules and know staph are present.

The probe is only cleaved by the staph bacteria's nuclease and not by a nuclease secreted by normal, healthy cells.

"That's the central idea, the underlying concept of our approach," McNamara said. "If the probe gets cleaved by serum nucleases, then our probe would be lit up all over the bloodstream. But since it's split only by staph nucleases, then we can pinpoint where the staph bacteria are active."

The research team plans to refine the probe so it can be detected deeper in the body. The researchers will also test the probe's performance with catheter infections.