Blue light may eliminate skin infections

Blue light effectively healed acute Pseudomonas aeruginosa burn infections in mice in a recent in vivo study.

Pointing to an in vitro study in which P. aeruginosa was more susceptible to blue light inactivation than were human keratinocyte cell line (HaCaT) cells, investigators with Massachusetts General Hospital and Harvard Medical School, Boston, noted there is a “therapeutic window” in which P. aeruginosa can be selectively inactivated by blue light, while host tissue cells are preserved.

Researchers applied blue light at 415 nm following bacterial inoculation. The treatment effectively reduced the P. aeruginosa burden in burns and also prevented “otherwise lethal” bacteremia in the mice, according to the study.

“Survival analysis revealed that blue light increased the survival rate of infected mice from 18.2 to 100 percent,” study authors wrote.

Investigators noted that more research would have to be conducted to determine whether bacterial cells develop resistance to blue light inactivation.

“As the mechanism of antimicrobial effect of blue light is suggested to be similar to that of PDT (photodynamic therapy), one can expect that the potential of bacterial resistance development to blue light is also less than that of conventional antibiotics,” study authors wrote.

The researchers said blue light therapy could be a safe and effective alternative to standard antimicrobial therapies for P. aeruginosa burn infections.

The study was published online ahead of print in Antimicrobial Agents and Chemotherapy.