Abstract
Purpose: :
To investigate whether microbial chemotaxis can be utilized to prevent and treat infectious keratitis, and specifically to examine the effect of the nonmetabolizable amino acid derivative DL-Trifluoroleucine on Pseudomonas aeruginosa.
Methods: :
Chemotaxis assays were performed by assessing the directional movement of Pseudomonas aeruginosa in response to a given stimulus on minimal media soft agar plates. Cornea penetration assays were performed using whole globes of pig eyes. We compared the number of bacterial colony forming units (CFU) present in pig corneas, preincubated with DL-trifluoroleucine or buffer alone, after pseudomonas exposure (ranging 2-8 hours).
Results: :
Pseudomonas aeruginosa was found to consistently migrate away from DL-trifluoroleucine on the soft agar migration assays (mean -13.7 mm, p < 0.05, n=3). The corneal penetration studies demonstrated that preincubation with DL-trifluoroleucine caused a 70% reduction in the degree of bacterial invasion (p < 0.0001, n=3).
Conclusions: :
The data indicate that DL-trifluoroleucine has a chemorepellent influence on Pseudomonas aeruginosa. This knowledge suggests that targeting microbial chemotactic behaviors can lead to the development of novel strategies to prevent and treat microbial infections such as infectious keratitis.
Keywords: keratitis • pseudomonas