The contribution of bacterial surface hydrophobicity to the process of adherence of pseudomonas aeruginosa to hydrophilic contact lenses

Ten isolates of Pseudomonas aeruginosa obtained from the corneas of patients with Pseudomonas keratitis adhered to soft contact lenses in significantly greater numbers than did six isolates from other body sites (P<05). However, there was no predominant serotype among the 10 corneal isolates tested. Isolates grown statically in broth at 37d̀C formed a pellicle and adhered two times as much to contact lenses as did isolates grown in broth while shaking which did not form a pellicle (P<01). The more adherent isolates (grown at 37d̀C) were shown to be more hydrophobic than the less adherent bacteria (grown at 26d̀C) by their propensity to accumulate at the interface between hexadecane and saline and their movement into polyethylene glycol from dextran. These corneal isolates agglutinated erythrocytes, a process that was inhibited by dilute solutions (as low as 0.01% of three commonly used surfactants. These same surfactants inhibited the adherence of Pseudo-monas aeruginosa to soft contact lens surfaces by as much as 52% It is concluded that hydrophobic interactions may significantly contribute to the ability of Pseudomonas aeruginosa to adhere to contact lenses.