Non-steroidal anti inflammatory agents decrease bacterial colonisation of contact lenses and prevent adhesion to human corneal epithelial cells

Purpose. To investigate non-steroidal anti-inflammatory agents (NSAIDs), salicylic acid, sodium diclofenac and ketorolac for inhibition of bacterial colonization of contact lenses (CL) and human corneal epithelial cells (HCE). Methods. CLs pre-colonised with Pseudomonas aeruginosa, Haemophilus influenzae, Staphylococcus epidermidis and Streptococcus pneumoniae were exposed overnight to NSAIDs and the number of viable bacteria on the CLs were calculated. Cytotoxicity of NSAIDs to HCE cells was evaluated with the MTT assay. Viable counts were used to measure the adhesion of P aeruginosa and S. epidermidis to HCE cells in the presence of the least cytotoxic NSAID. Results. All NSAIDs significantly decreased bacterial colonization of CLs in a dose-dependent manner. Salicylic acid (100mM) completely inhibited colonisation of all species tested and was the least cytotoxic. Salicylic acid also prevented adhesion of P aerugainosa and S. epidermidis to HCE (60% and 58% inhibition at 60 mM at 2 hours). Conclusions. Salicylic acid demonstrated potential as a compound for incorporation into anti-bacterial strategies to prevent bacterial contamination of contact lenses. This stud), highlighted the potential for NSAIDs as anti-bacterial agents and indicates that this class of compound should be investigated for other suitable candidates.