Archive for Thursday, February 21, 2002

would help patients detect, identify bacteria

February 21, 2002


— Scientists are working on a "smart bandage" that would detect specific bacteria in a wound and eventually may help people self-diagnose illnesses and free doctors to focus on more seriously ill patients.

Scientists at the University of Rochester have yet to incorporate their sensor chip onto a gauze dressing. But once completed, the bandage would sense the germ and change color to alert a patient to the possibility of infection.

Among the bacteria the bandage potentially could pinpoint are those that cause strep throat and skin staph infections. Others such as E. coli, salmonella and listeria, which can cause abdominal cramps, fever and severe diarrhea, also are being targeted.

Eventually, patients would be able to treat their own infections by scanning the bandage into a personal computer with software that identifies the bacteria and offers a solution via an online medical database, said Benjamin Miller, a chemist involved in the project.

It is increasingly important to monitor health at home because it saves unnecessary trips to the doctor's office, Miller said.

"Right now, our medical system is overwhelmed with many cases of relatively minor infections," he said. "If we can help shift some of the routine diagnoses to simple at-home tests, then we give physicians more time to treat patients with more serious ailments."

The "smart bandage," a sand-grain-sized wafer of silicon chip, can differentiate between two classes of bacteria known as gram-negative and gram-positive, Miller said.

The bandage would be designed for use on any type of wound  including scrapes, cuts, punctures or lesions. Depending on the class of bacteria, patients would treat their infections with the appropriate antibiotic or other medicine.

In 1884, Danish bacteriologist Christian Gram developed a staining technique that classified bacteria based on the cell wall's ability to retain a dye. In the procedure, gram-positive bacteria stain purple, gram-negative red.

The "smart bandage" introduces a modern twist by performing the stain quickly and accurately.

"The gram stain has been an important tool in analyzing bacteria for more than a century, but it's amazing to me that we're still using a procedure that's effectively out of the Stone Age," Miller said.

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