Clinical bacteriology of dacryocystitis in adults.

To better define the spectrum and relative incidence of pathogens causing dacryocystitis in adults, samples of purulent lacrimal sac contents were obtained from 236 patients undergoing dacryocystorhinostomy for a clinical diagnosis of dacryocystitis. Positive culture results were obtained in 52.5%. Cultures were pure, consisting of a single organism in 71%, and were mixed in 29%. Gram-positive organisms were most common, accounting for 64.5% of the isolates. Staphylococcus epidermidis, comprising 27.3% of the isolates and Staphylococcus aureus, comprising 22.1% of the isolates, were the most frequently encountered organisms. Gram-negative organisms were present in 27.3% of the isolates with Pseudomonas aeruginosa the most common, accounting for 8.7% overall. Anaerobic organisms were found in 7.0% of the isolates with Propionibacterium acnes the most frequent, recovered in 4.7% overall. Unexpected findings included the paucity of Streptococcus pneumoniae organisms recovered and the high incidence of involvement by gram-negative and anaerobic organisms.