A new study by researchers at the University of Southern California School of Medicine has shed light on a more effective way to detect bacteria while cleaning wounds. The effective method is autofluorescence imaging, in which a portable device “lights up” bacteria that were previously invisible to the human eye.
When a violet light is shone on the cell walls of any bacteria, molecules in their walls light up, and different types of bacteria appear in different colors, allowing doctors to immediately determine the amount and types of bacteria present in the wound.
Bacteria that colonize wounds
Millions of people worldwide suffer from chronic wounds, which are wounds that do not heal after a few months. Almost all of these wounds contain bacteria, and if left untreated and untreated, they can lead to severe infection and complications, including amputation if the infection involves a limb.
This is especially true for patients with diabetic foot ulcers (open wounds), which affect one-third of people with diabetes. According to the American Diabetes Association, about 20 percent of those who develop a diabetic foot ulcer will require lower extremity amputation.
When doctors clean a wound, they remove as much bacteria as possible. However, they face a major challenge: they cannot see all the bacteria with the human eye, and some may be missed during cleaning.
“We hope this new technology will help surgeons improve their accuracy when identifying and removing bacteria from wounds and thus improve patient outcomes, especially for those with diabetic foot wounds,” said David J. Armstrong, M.D., a podiatrist and limb preservation specialist at USC School of Medicine and lead author of the study. “Early detection and removal of bacteria from a wound is vital to preventing preventable amputations,” he added, according to EurekAlert.
Bacterial lighting or traditional methods?
The research, published in Advances in Wound Care on July 31, which includes a review of 25 studies investigating the effectiveness of autofluorescence imaging in treating diabetic patients with foot ulcers, reveals that autofluorescence imaging can identify bacteria in wounds in about 9 out of 10 patients that conventional assessments miss.
Traditionally, doctors clean wounds, then send tissue samples to a lab to identify specific types of bacteria present in the wound and determine the best treatment protocol based on those results, such as starting the patient on antibiotics or providing a special type of wound dressing. That process can take days, during which time an infection can set in, Armstrong said.
With automated fluorescence imaging, doctors are able to make medical decisions while cleaning wounds, rather than waiting for lab results to begin treatment.
Another benefit of this technique is that if the bacteria are detected early, the patient may avoid antibiotics, which may be taken for a longer period during wound care, thus avoiding potential antibiotic resistance.
“This real-time intervention could allow for faster and more effective wound healing,” Armstrong said.
Doctors at the University of Southern California Hospital are successfully using this technique to treat patients with chronic wounds, including diabetic foot ulcers.
“I look forward to further research in this area, and we hope to see cardiac imaging become the standard of care for wound care in the near future,” Armstrong added.