Antibiotics are one of the most important scientific discoveries of the 20th Century, but their usefulness is rapidly fading. Excessive use of antibiotics leads to bacterial resistance, which may lead us to a future when simple infection will again be life-threatening. Now, researchers at Purdue University have found that blue light can weaken a particularly annoying “superbug” and make it again affected by mild fungicides.

Staphylococcus aureus is a type of common bacteria, most of which are harmless, but some strains cause more problems. Methicillin-resistant Staphylococcus aureus (MRSA) is a particularly troublesome bacterium, the most dangerous for people with compromised immune systems, which means it can cause serious infections in hospitals and nursing homes. Unfortunately, this has become increasingly difficult to treat - it is not only resistant to methicillin, but also to a growing number of other common antibiotics.

  New antibiotics are still under development, but of course the bacterium will inevitably develop resistance. Therefore, scientists are working hard to find some long-term solutions beyond superbugs’ adaptation capability, such as antibacterial materials that quickly destroy bacteria or photosensitive nanoparticles that release reactive oxygen to kill super bacteria.

 At the same time, researchers at Purdue University developed their own light therapy. The team found that MRSA can be weakened by “photobleaching” - exposing the bacteria to blue light can radically eliminating their color. Since these pigments are part of the process of bacterial infection of the host, this may reduce their ability to cause damage.

 “When you bleach something in the washing machine, you use chemicals to remove the color,” said Mohamed Seleem, author of the study, “We are doing something very similar here, but we are using blue light.”

The light itself does not kill MRSA. It just reduces its defenses, allowing drugs and other molecules to do the rest, even those bacteria can usually resist them. In tests on mice with MRSA-infected wounds, the researchers found that mild fungicides like hydrogen peroxide can effectively destroy the bacteria that are weakened by blue light.

 The team has patented a device to treat MRSA-infected wounds. The idea is that it will take the shape of a small box with lights and illuminate the wound through a hole. Importantly, scientists have discovered that the light is safe on mammalian cells.

 “This new tool can treat any MRSA-infected surface wounds, which are often difficult to treat,” Seleem said, “The device itself is very small and easy to use. We hope that anyone can carry it with them in the next few years.”

 The study was published on Advanced Science.

Source：LEDinside