Abstract
Purpose: :
To identify the most common organisms isolated from different anatomic locations of the eye.
Methods: :
A retrospective review of 1367 positive cultures taken from the eyes of 1040 patients at one tertiary referral center Jules Stein Eye Institute -UCLA over a seven year period from January 2003 to September 2009.The pathogens were further categorized based on different anatomical locations including eyelid, conjunctiva, cornea, and vitreous.
Results: :
There were a total of 1942 pathogens isolated. Among these cultures 96 % were positive for bacteria, 4 % were fungi. In 353 (26%) cultures, two pathogens were isolated and 95 cultures (7%) grew 3 or more organisms. Gram positive isolates were the most common organism (1276/66%) followed by gram negative bacteria (587/30%) and fungi (79/4%). The most common bacterial pathogens from the total culture results were coagulase-negative Staphylococcus (587/30%), Staphylococcus aureus (253/13%), Streptococcus viridians (164/8%), and Corynebacterium species (141/7%). Candida species accounted for 52% (41) of the fungal isolates. When the isolates were subcategorized based on different anatomical locations, coagulase negative Staphylococcus remained the most common in all locations except the aqueous where Streptococcus viridans and Candida species were the most common isolates accounting for 21% of the positive cultures. The second most common pathogen was Pseudomonas aeruginosa (55/12%) in cornea, and Staphylococcus aureus in three other locations, eyelid (45/20%), conjunctiva (58/14%) and vitreous fluid (4/9%).
Conclusions: :
Gram positive bacteria were identified in the vast majority of eye infections at a referral based tertiary medical center. Antibiotics effective against gram positive bacteria should be included as the first line empirical treatment in all eye infections and additional anti-Pseudomonas coverage in keratitis.
Keywords: cornea: clinical science • bacterial disease • keratitis