Blue light could treat superbug infections: Study

Boston: Exposing superbugs to blue light can render them defenseless against even mild antiseptics, according to a study that may help leverage the fight against the growing global threat of drug-resistant bacteria.

Methicillin-resistant Staphylococcus aureus (MRSA), a bacterium that causes infection in various parts of the body, is often called a "superbug" thanks to its ability to dodge many common antibiotics. Although most MRSA infections are not serious, some can be life-threatening, sometimes resulting in amputation of the infected appendage, researchers said in a statement.

Rather than trying multi-drug combinations or wasting precious time determining which medicine to prescribe, doctors could soon use light therapy for disarming the superbugs, according to a study published in the journal Advanced Science. Researchers at Purdue University and Boston University in the US have discovered that exposing the bug to blue light can render it defenseless against antiseptics as mild as hydrogen peroxide.

"This new tool can treat any superficial wound infected with MRSA, which are typically very difficult to treat," said Mohamed Seleem, a professor of microbiology at Purdue University. "The device itself is very small and easy to use. We're hoping that in the next few years, anyone could carry it around in their purse," said Seleem. Some bacteria, including certain strains of staph, produce pigments, associated with the organism's ability to damage the host. If the pigment is reduced, the organism's activity in the body may also be curbed. This practice is known as photobleaching, researchers said.

"When you bleach something in the wash machine, you're extracting the color using chemicals. What we're doing here is similar, but we're using blue light," said Seleem. After achieving promising results in vitro, the researchers exposed mice with MRSA-infected wounds to different wavelengths of light. The infections responded especially well to light in the blue region, and combined with a low-concentration hydrogen peroxide, were reduced significantly.