Effect of poloxamer 407 on the adherence of Pseudomonas aeruginosa to corneal epithelial cells.

The effect of poloxamer 407 on Pseudomonas aeruginosa adherence to cultured epithelial cells from rabbit corneas was investigated. Three methods of bacterial quantification were used to assess P. aeruginosa adherence: scanning electron microscopy (SEM) counts, radioactivity counts, and viable bacteria counts. Confluent monolayers of rabbit corneal epithelial cells were incubated in agitation for 30 min at room temperature with H3-labeled or nonradiolabeled P. aeruginosa (10(10) bacteria/ml) in a solution of poloxamer 407 [2% or 4% in phosphate-buffered saline (PBS)] or PBS as control. Cell monolayers were washed to remove nonadherent bacteria and fixed with 2.5% glutaraldehyde and processed for SEM or processed for radioactivity counting or for culture on agar plates. The results showed that both solutions of poloxamer 407 inhibited approximately 75% of the bacterial adherence to epithelial cells (p < 0.05). Similar percentages of bacterial inhibition were obtained using the three methods of bacterial quantification. The use of an antiadherent agent such as poloxamer 407 in eye drops could possibly be a prophylactic approach to P. aeruginosa keratitis.