MODULATION OF BACTERIAL ADHESION TO HYDROGEL CONTACT-LENSES BY ALBUMIN

Purpose, The purpose of this investigation was to measure the abilitie s of Pseudomonas aeruginosa and Staphylococcus epidermidis strains to adhere to two hydrogel lens materials and measure the effect of a prot ein-coated surface on the number of adhered bacteria. Methods. Protein s absorbed to contact lenses during sleep were extracted, subjected to sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PACE), and probed for the presence of albumin, Bacterial adhesion was measur ed by counting bacteria adherent to contact lenses coated in vitro in increasing concentrations of albumin, examining the ability of albumin in solution to prevent adhesion to albumin-coated lenses, and examini ng the topography of bacterial adhesion by electron microscopy, Result s, Albumin adsorbed to lenses during overnight wear. in vitro studies demonstrated that Polymacon lenses adsorbed more albumin than Etafilco n A lenses, In general, the numbers of adherent bacteria increased wit h increasing concentration of albumin, Bacteria adhered in higher numb ers to Polymacon lenses than Etafilcon A (p < 0.05). P. aeruginosa sho wed an increased adhesion as the amount of albumin on Etafilcon A lens es increased. There was a decrease in numbers of bacteria adhering per milligram of albumin as the level of albumin increased on Polymacon l enses, Cells tended to adhere to ''deposits'' on albumin-coated lenses . Discussion. Albumin adsorbed onto the surface of contact lenses modu lated the ability of P. aeruginosa and S. epidermidis to adhere. P. ae ruginosa is commonly associated with contact lens-associated microbial keratitis, where bacterial adhesion to contact lenses is believed to be an important first step in the pathogenesis of the disease.