Blue light phototherapy could be an effective way of killing bacteria.

The studies provide evidence that "blue light in the range of 405-470 nm wavelength is bactericidal and has the potential to help stem the ongoing pandemic of MRSA and other bacterial infections."
The researchers found that photodynamic therapy and methylene blue delivered directly into the root canal of a human tooth infected with a bacterial biofilm was able to destroy both Gram-positive and Gram-negative bacteria, disrupt the biofilms, and reduce the number of bacteria adhering to the tooth.
Raymond J. Lanzafame, and colleagues demonstrated significantly greater bacterial reduction in the treatment of pressure ulcers in mice using a combination of photoactivated collagen-embedded compounds plus 455 nm diode laser irradiation compared to irradiation alone or no treatment.
The studies were published in Photomedicine and Laser Surgery.
Source-ANI