Abstract
Purpose: :
The efficacy of a novel fluoroquinolone (besifloxacin) was evaluated in a prophylactic rabbit model of methicillin-resistant Staphylococcus aureus (MRSA)-induced endophthalmitis in comparison to other marketed quinolones, including levofloxacin, moxifloxacin, and gatifloxacin.
Methods: :
Bacterial endophthalmitis was induced by intracameral injection of an MRSA suspension (3 to 4 x 105 colony-forming units/eye). Inoculated eyes were treated topically with saline, levofloxacin, moxifloxacin, gatifloxacin, or besifloxacin (6 eyes per agent except for saline, which used 12 eyes) prophylactically every 15 min for 1 h before inoculation and five additional times over the next 24 h. Clinical examination was conducted at 24 h post-inoculation; ophthalmic findings were graded for severity. Rabbits were euthanized after ophthalmic examination, and the aqueous and vitreous humor were collected and viable bacteria enumerated.
Results: :
All test agents except saline successfully eradicated viable bacteria, with no bacterial count in aqueous samples from any of the test agents. However, based on improvement of clinical score, levofloxacin, moxifloxacin, and gatifloxacin were inefficacious in this model. Only besifloxacin produced statistically significant clinical reduction of signs of endophthalmitis versus saline treatment alone.
Conclusions: :
The novel fluoroquinolone besifloxacin exhibited superior efficacy to other ophthalmic fluoroquinolones in a rabbit model of MRSA-induced endophthalmitis. These data support the further clinical evaluation of besifloxacin for a variety of ocular anti-infective indications.
Keywords: bacterial disease