Evaluation of normal ocular bacterial flora with two different culture media.

Abstract

The purpose of this study was to determine if the use of broth culture medium is efficient in investigating bacterial flora of the normal eyelid and conjunctiva. Samples from the conjunctiva and eyelid of healthy patients of various ages who were undergoing ocular surgeries were obtained and cultured at 3 periods: before topical antibiotic prophylaxis, in the postoperative period during topical antibiotic treatment, and 15 days after discontinuation of antibiotic use. Samples were inoculated into both brain heart infusion broth and blood agar plate, and the growth results of both media were analyzed. Brain heart infusion broth medium showed a significantly higher bacterial growth of gram-positive cocci in most periods. The solid blood agar medium had a higher recovery of gram-positive bacilli before prophylaxis only in the older patients. Our results show that a more complete analysis of eyelid and conjunctival flora can be obtained using both liquid and solid media to increase the chances of isolate recovery. The inclusion of liquid media in this analysis was even more relevant in the period of concomitant use of antibiotic treatment.