Abstract
Purpose: :
To investigate the ultrastructure of lens capsule for experimental endophthalmitis in removed porcine eyes.
Methods: :
Staphylococcus epidermidis, ATCC 35984 (biofilm-producer) and methicillin-resistant Staphylococcus aureus (MRSA), UA-1 (clinically isolated strain) were used. Small quantities of the culture were subcultured on the BHI broth overnight at 37°C. Then, cultures were kept frozen at -75°C in MicrobankTM (PRO-LAB Diagnostics, Toronto, Canada ). Phacoemulsification were performed in fresh removed porcine eyes, the incision size was increased to approximately 5-6 mm. Two beads from MicrobankTM were inserted into the capsular bag. Wound closure was achieved with a 8-0 Vicryl suture, 0.1-0.2 ml of the BHI broth was administered in the anterior chamber of the surgical pig eye at the end of surgery.Those porcine eyes were kept in a sterile 50ml plastic centrifuge tubes with 10ml corneal storage media (EP2, Kaken Pharmaceutical Co., Ltd., Tokyo, Japan) at 37°C after surgery. After incubation for 24 hours, those eyes were fixed with 2% glutaraldehyde for scanning electron microscopy (SEM).The bacteria on the surface of lens capsule were examined by SEM. The bacterial population at posterior capsule surface was also enumerated.
Results: :
As for the S.epidermidis, those bacteria aggregated on the surface of lens capsule, while MRSA infiltrated to the lens capsule. Rates of bacteria-positive SEM fields were 10% (control), 37% (S.epidermidis) and 78% (MRSA). Moreover, rates of dozens bacteria-positive SEM fields were 16% (S.epidermidis) and 47% (MRSA).
Conclusions: :
Bacteria may spread to the vitreous cavity and anterior chamber passing through the lens capsule in experimental endophthalmitis. Permeability of capsule membrane may be depending on bacterial species.
Keywords: endophthalmitis • anatomy • microbial pathogenesis: clinical studies