Blue Light Destroys MRSA

Researchers at the New York Institute of Technology have discovered that a certain wavelength of blue light destroys the virulent antibiotic-resistant strain of the Staph bacteria known as MRSA.

In a process known as photo-irradiation, two common strains of methicillin-resistant Staphylococcus aureus (MRSA) were exposed to various doses of 470 nm blue light, a wavelength that does not emit ultraviolet radiation. The team found that the greater the dose of light used, the more microorganisms were killed. Up to 90.4% in colonies of the MRSA strains US-300 and IS-853 were destroyed using this method.

The precise method by which this process works is not fully understood but it is believed the DNA of the bacteria absorbs the energy of these specific wavelengths, causing irreparable damage and eventual cell death. Researchers have long known the bactericidal effects of 400-nm light and ultraviolet radiation, with research as far back as 1930. Blue light of 415 nm has been used to treat acne cases by destroying Propionibacterium acne, and the infectious Pseudomonas aeruginosa is killed by light with a wavelength of 405 nm.

MRSA poses an increasing health threat, as approximately 40% to 50% of all staphylococcal strains have developed resistance to modern antibiotics such as methicillin. Less than 5% of staphylococcal strains are currently susceptible to penicillin treatments. The use of blue light in the laboratory suggests it may be effective for the treatment of cutaneous and subcutaneous infections without promoting further resistance to antibiotics.

These results are scheduled to appear in the April issue of Photomedicine and Laser Surgery.

Source: ScienceDaily; Photo: Wikipedia