Abstract
Purpose: :
Endophthalmitis secondary to cataract surgery caused by Enterococus faecalis, often results in significant vision loss. However, little is known about the pathogenetic mechanisms concerning the condition. This study was designed to investigate the possible contribution of the gelatinase using a rabbit endophthalmitis model.
Methods: :
The strains used were E. faecalis OG1S (gelatinase positive) and E. faecalis OG1X ( isogenic gelatinase negative derivative of OG1S). After the lens removal by phacoemulsification, 2×104 colony-forming units of either strain were inoculated into the lens bag. Changes in bacterial growth, electroretinography (ERG), and pathology of the eyes were comparatively monitored and recorded throughout the course of the infection.
Results: :
The level of the growth in the anterior chamber and vitreous cavity were similar in both strains studied. The infection with OG1S resulted in a significantly greater reduction of ERG’s B-wave amplitudes than those with OG1X. Histological examination revealed that the posterior lens capsules were severely affected in the eyes infected with OG1S, and inflammatory cells and cocci were found in the anterior vitreous cavity 24 hours after the infection. By 48 hours after the infection, retina was profoundly destroyed in the eyes infected with OG1S with the accumulation of massive inflammatory cells. In contrast, no significant pathological changes were noted in the posterior lens capsules and retina of the eyes infected with OG1X.
Conclusions: :
Gelatinase plays a significant role in the pathogenesis of E. faecalis-induced postoperative endophthalmitis.
Keywords: endophthalmitis • microbial pathogenesis: experimental studies • bacterial disease