The Effects of Blue Light on the Biofilm Formation and Disruption of Staphylococcus aureus

The formation of biofilm complicates the treatment of Staphylococcus aureus infections. This experiment measured the effect of 470 nm blue light, a possible antimicrobial agent, on biofilm formation using a biofilm assay. Blue light irradiation for 2 hours on dilute cultures inhibited biofilm formation, and irradiation on saturated cultures after 48 hours of growth resulted in strain-specific changes in the amount of biofilm. There was a positive correlation between cell count and biofilm formation and no correlation between cell count and biofilm disruption. Strain specific variation is observed for the formation of biofilm per cell on blue light treated cultures. It is hypothesized that molecular and genetic variability among strains led to these results. Blue light has the potential to serve as a preventative for infections in a clinical setting, but further investigation into the variation seen in this study is needed to make progress in treating disease.