(3gj) Bactericidal Activity and Mechanism of Blue Light

Hospital-acquired infections (HAI) cause mortality and morbidity in hospitals. Although frequent cleaning with disinfectants can effectively prevent the contact transmission of microorganisms, surface corrosion, microbial tolerance and potential harmful residues resulting from ordinary chemical disinfectants are main concerns. Pulsed blue LED lights are recently reported with obvious bactericidal activity. This study works on the bactericidal activities and mechanism of two types of pulsed blue light, i.e., 470 nm and 405 nm. Results showed that pulsed 470 nm and 405 nm blue LED lights not only saved energy but also effectively reduced the gram positive and negative bacteria as well as MDROs. By measuring the sub-lethal rate, DNA and protein leakage from the bacteria, it revealed that 405 nm light can induce deconstruction of bacterium membrane. Genotoxicity test indicated the bactericidal mechanism of 470 nm light through destroying the DNA structure of bacteria.