Posters

Studying the growth pattern of Pseudomonas aeruginosa bacteria in the cornea using two human ex-vivo models of corneal infection

Poster Details

First Author: A.Elsahn UK

Co Author(s):    I. Lewis   M. Stephens   D. Ting   H. Dua   I. Mohammed        

Abstract Details

Purpose:

To study the growth pattern of Pseudomonas aeruginosa bacteria in the cornea after corneal infection in human microbial keratitis

Setting:

Basic science laboratory study

Methods:

Human whole donor corneas were used in this project. Bacterial suspensions of GFP-expressing P. aeruginosa PAO-1L were prepared. Two models of infection were utilised; a trans-epithelial and an intra-stromal model. In the trans-epithelial model, corneal button was scored and 100 microlitres of bacterial suspension were added to the surface. In the intra-stromal model, fifty microlitres of bacterial suspension were injected into the corneal stroma from the endothelial side using a 25G hypodermic needle. The corneas were incubated in medium for up to 72h. Infected tissue was sectioned, fixed and examined under either a light or a laser confocal fluorescence microscope

Results:

In the trans-epithelial model, GFP-expressing PAO-1L bacteria were observed to grow over the surface of the epithelial and penetrate into the corneal stroma. In the intra-stromal model, bacteria were observed to grow locally at the site of injection. The growth rate increased steadily in both models. Eventually, bacterial spread was observed in the corneal stroma in both models although more pronounced with the trans-epithelial model

Conclusions:

We have established ex-vivo models of bacterial keratitis and demonstrated that P. aeruginosa can penetrate into, and grow within, the corneal stroma after infection. The trans-epithelial model produced results that were probably more reflective of what happens in a real-life, clinical microbial keratitis scenario

Financial Disclosure:

None