Purpose: To analyze in vitro antibiotic susceptibility of bacterial isolates from patients with bacterial keratitis at the National Taiwan University Hospital over the past 12 years.
Design: Retrospective cross-sectional study.
Methods: Medical records were reviewed for patients with culture-proven bacterial keratitis at the National Taiwan University Hospital from January 1994 to December 2005. Microbial isolation and in vitro antibiotic susceptibility were analyzed.
Results: A total of 272 pathogens were isolated from 254 eyes. Pseudomonas species were the most commonly isolated organisms (46.7%), followed by Staphylococcus species (11%), Propionibacterium species (8.1%), Streptococcus species (7.6%), and nontuberculous Mycobacteria (6.6%). There was no significant change in antibiotic susceptibility in the strains of Staphylococcus, Streptococcus, Pseudomonas, or nontuberculous Mycobacteria during the study period. From 1994 to 2005, 81.8% of the gram-negative organisms were susceptible to the combination of cefazolin and gentamicin, whereas 95.8% were susceptible to ciprofloxacin (P < .001). For all bacterial isolates, 83.7% and 89.7% were susceptible to the combination of cefazolin and gentamicin and the combination of cefazolin and ciprofloxacin, respectively (P < .001).
Conclusion: There was no increase in drug resistance in strains of Pseudomonas, Staphylococcus, Streptococcus, or nontuberculous Mycobacteria from 1994 to 2005. Ciprofloxacin is a more efficacious choice than the combination of cefazolin and gentamicin for gram-negative bacterial keratitis in Taiwan. The combination of cefazolin and ciprofloxacin is an effective empirical therapeutic regimen for bacterial keratitis.