Blue Light Destroys Two MRSA Strains

Two common strains of methicillin-resistant Staphylococcus aureus (MRSA) were virtually eradicated in the laboratory by exposing them to a wavelength of blue light, in a process called photo-irradiation that is described in a paper published online ahead of print in Photomedicine and Laser Surgery. The article will appear in the April 2009 issue (Vol. 27, No. 2) of the peer-reviewed journal published by Mary Ann Liebert, Inc.

Antibiotic-resistant bacterial infections represent an important and increasing public health threat. At present, fewer than 5 percent of staphylococcal strains are susceptible to penicillin, while approximately 40 percent to 50 percent of Staph aureus isolated have developed resistance to newer semisynthetic antibiotics such as methicillin as well.

Chukuka S. Enwemeka, Deborah Williams, Sombiri K. Enwemeka, Steve Hollosi, and David Yens from the New York Institute of Technology had previously demonstrated that photo-irradiation using 405-nm light destroys MRSA strains grown in culture. In the current study, "Blue 470-nm Light Kills Methicillin-Resistant Staphylococcus aureus (MRSA) in Vitro," the authors exposed bacterial colonies of MRSA to various doses of 470-nm light, which emits no UV radiation.