Abstract
Abstract: :
Purpose: Salicylic acid has been shown to have the ability to interfere with microbial biofilm formation on medical polymers. We were interested in determining whether salicylic acid decreased the adhesion of Pseudomonas aeruginosa and Staphylococcus epidermidis to human corneal epithelial cells (HCE). Methods: Salicylic acid was assessed for cytotoxicity on HCE cells using various concentrations of salicylic acid (0-60mM) incubated with HCE cells (370C, 2 to 24hrs). Cytotoxicity was then evaluated by using 12mM 3-(4,5-dimethlthiazol-2-yl)- 205-diphenyl tetrazolium bromide (MTT). For the bacterial adhesion assay, HCE cells were incubated with P. aeruginosa and S. epidermidis in the presence of salicylic acid (non-cytotoxic concentrations) at 370C for 2hrs. The bacteria adhered to HCE cells were recovered by adding lysis solution (Triton X 100) to HCE cells and the colony-forming units were counted by plating method. Results: Salicylic acid showed 4% and 14% cell death with 20mM and 60mM solution respectively and exhibited less than 20% cell death after 24hrs at concentration = 20mM. Salicylic acid inhibited the binding of P. aeruginosa and S. epidermidis to HCE cells in dose dependent manner. In comparison to controls at 2hrs, Salicylic acid (20mM) inhibited the adhesion of P.aeruginosa to HCE cells by 28% and 60% at concentration of 60mM. Number of colonies of S.epidermidis bound to HEC cells decreased by 22% and 58% with 20mM and 60mM salicylic acid respectively compared to the control within two hours. Conclusions: Salicylic acid has inhibitory effects on the adhesion of P. aeruginosa and S. epidermidis to cultured HCE cells suggesting that this compound may be useful in preventing bacterial adhesion to HCE cells in vivo.
Keywords: bacterial disease • microbial pathogenesis: experimental studies • drug toxicity/drug effects