Abstract
Purpose: :
To compare the effect of gatifloxacin 0.3% and ciprofloxacin 0.3% on bacterial isolates taken from patients with acute bacterial corneal ulcers.
Methods: :
75 patients were enrolled into a multicenter, investigator–masked, clinical comparison of gatifloxacin 0.3% and ciprofloxacin 0.3% in the treatment of acute bacterial corneal ulcers. Microbiological culture samples were obtained from the area of ulceration before treatment to evaluate the type of organisms present and susceptibility to antibiotics. 72 and 73 culture samples were available to test the susceptibility to gatifloxacin and ciprofloxacin respectively.
Results: :
The most common organisms isolated were Streptococcus pneumoniae (42/73; 57.5%) and Pseudomonas aeruginosa (12/73; 16.4%). 41 out of 42 culture samples (97.6%) with Streptococcus pneumoniae isolates were susceptible to gatifloxacin (MIC90: 0.75 µg/mL), compared with 5 out of 42 samples (11.9%) that were susceptible to ciprofloxacin (MIC90: 4 µg/mL). A slightly smaller percentage of Pseudomonas aeruginosa isolates were susceptible to gatifloxacin [83.3% (10/12); MIC90: 3 µg/mL], and ciprofloxacin: [91.7% (11/12); MIC90: 1 µg/mL). A total of 93.1% (67/72) of all organisms were susceptible to gatifloxacin (MIC90: 2 µg/mL), while 38.4% (28/73) were susceptible to ciprofloxacin (MIC90: 4 µg/mL). Similarly, 94.4% (51/54) of all gram positive organisms were susceptible to gatifloxacin (MIC90: 1 µg/mL) while 20.4% (11/54) were susceptible to ciprofloxacin (MIC90: 4 µg/mL); 88.9% (16/18) of all gram negative organisms were susceptible to gatifloxacin (MIC90: 3 µg/mL) while 89.5% (17/19) were susceptible to ciprofloxacin (MIC90: 2 µg/mL).
Conclusions: :
Gatifloxacin exhibited greater antimicrobial efficacy than ciprofloxacin against gram positive organisms in general and Streptococcus pneumoniae, specifically. Gatifloxacin and ciprofloxacin exhibited high antimicrobial efficacy against gram negative organisms.. Because of its broader spectrum of coverage, gatifloxacin may be a better initial therapy than ciprofloxacin for acute bacterial corneal ulcers.
Keywords: antibiotics/antifungals/antiparasitics • cornea: clinical science