Antibiotic susceptibility of bacterial isolates from bacterial keratitis cases in a university hospital in Taiwan.

Abstract

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. Retrospective cross-sectional study. 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. 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). 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.