Ong J, Godfrey R, Nazarian A, Tam J, Drake L, Isaacson B, Pasquina P, Williams D

Biofilm contamination is often present at the skin-implant interface of transfemoral osseointegrated implants leading to frequent infection, irritation, and discomfort. New biofilm management regimens are needed as the current standard of washing the site with soap and water is inadequate to manage infection rates. We have investigated the potential of antimicrobial blue light which has reduced risk of resistance development and broad antimicrobial mechanisms. Our lab has developed an aBL device uniquely designed for an ex vivo system based on an established ovine OI implant model with Staphylococcus aureus ATCC 6538 biofilms as initial inocula. Samples were irradiated with aBL or washed for three consecutive days after which they were quantified. Colony forming unit (CFU) counts were compared to a control group (bacterial inocula without treatment). After one day, aBL administered as a single 6 h dose or two 1 h doses spaced 6 h apart both reduced the CFU count by 1.63 log10 ± .02 CFU. Over three days of treatment, a positive aBL trend was observed with a maximum reduction of ~2.7 log10 CFU following 6 h of treatment, indicating a relation between multiple days of irradiation and greater CFU reductions. aBL was more effective at reducing the biofilm burden at the skin-implant interface compared to the wash group, demonstrating the potential of aBL as a biofilm management option.

Ong, J., Godfrey, R., Nazarian, A., Tam, J., Drake, L., Isaacson, B., Pasquina, P., & Williams, D. (2023). Antimicrobial Blue Light as a Biofilm Management Therapy at the Skin-Implant Interface in an Ex Vivo Percutaneous Osseointegrated Implant Model. Journal of Orthopaedic Research. https://doi.org/10.1002/jor.25535