Purchase this article with an account.
Geoffrey W. Burnham, H D. Cavanagh, Danielle M. Robertson; Neutrophil-enhanced Pseudomonas aeruginosa Biofilms on Silicone Hydrogel Contact Lenses. Invest. Ophthalmol. Vis. Sci. 2011;52(14):6506.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
In animal models, extended contact lens wear with concurrent bacterial challenge results in significant neutrophil accumulation. Recently we have reported that Pseudomonas aeruginosa (PA) biofilms formed on hydrogel lenses are significantly increased in the presence of neutrophils.The purpose of this study is to evaluate neutrophil-enhanced PA biofilm formation on silicone hydrogel contact lenses.
A fully invasive corneal isolate that has been stably conjugated to GFP, strain PA6487, was used in all experiments. Neutrophils were isolated from human blood using a percoll gradient separation and activated by brief exposure to phorbol 12-myristate 13-acetate. Neutrophils were utilized at a concentration of 8x106cells/well. Unworn lotrafilcon A lenses were incubated in 1mL of bacterial suspension at a concentration of 1x108CFU/mL for 2 hours. After being washed in PBS, lenses were incubated overnight in RPMI with 2% Heat inactivated platelet poor plasma either with or without neutrophils. The lenses were incubated in their respective solutions for 24 hours at 37OC. Biofilm formation was evaluated using laser scanning confocal microscopy and colony forming unit (CFU) analysis.
Primary attachment of PA was confirmed at 2 hours by confocal microscopy and CFU analysis. No bacteria were harvested from the non-bacteria exposed control lens. After a 24 hour incubation in the presence of neutrophils, confocal microscopy demonstrated increased density and an alteration of the architecture of the biofilm. CFU analysis confirmed an increase in viable PA in the neutrophil-enhanced biofilm (p=0.002).
These data demonstrate that intense corneal inflammation associated with PA contamination results in enhanced biofilm formation on silicone hydrogel contact lenses. Further studies are required to determine the efficacy of currently available cleaning regimens against neutrophil-enhanced biofilms on contact lens surfaces.
This PDF is available to Subscribers Only