Abstract
Abstract: :
Purpose: Pseudomonas keratitis is a rapidly developing and destructive infection of the cornea. Although the successful treatment of such bacterial keratitis with a variety of ocular antibiotics is well established, emergence of resistant isolates of Pseudomonas Aeruginosa poses a future threat to this success. The purpose of this study was to evaluate the antibiotic susceptibilities of random clinical isolates of P. aeruginosa to levofloxacin (LE), moxifloxacin (MX) and gatifloxacin (GA), potential agents for the treatment of Pseudomonas keratitis. Methods: One hundred (100) consecutive clinical isolates were obtained from the Microbiology Laboratory of the Mount Sinai Hospital. The minimum inhibitory concentrations (MICs) of the above clinical isolates were determined using Etests (AB Biodisk, Solna, Sweden), performed in compliance with the National Committee for Clinical Laboratory Standards (NCCLS). The antibiotic concentrations tested ranged from 0.002 – 32 µg/ml (continuous gradient). Results: The majority of the isolates were susceptible to levo–, moxi– and gatifloxacin [LE: 67% (Mean MIC=0.63±0.61); MX: 63% (Mean MIC=0.66±0.48); GA: 68% (Mean MIC=0.55±0.50)], yet significant numbers of those collected were resistant (LE: 25% (Mean MIC=29±7); MX: 28% (Mean MIC=26±10); GA: 21% (Mean MIC=28±9)]. Conclusions: The treatment of bacterial keratitis caused by Pseudomonas aeruginosa with the tested fluoroquinolones: levofloxacin (LE), moxifloxacin (MX) and gatifloxacin (GA), has a high likelihood of success. However, in vitro resistance was noted with all three fluoroquinolones. Correlations with source of clinical isolates and MICs of each fluoroquinolone will also be presented.
Keywords: Pseudomonas • drug toxicity/drug effects • drug toxicity/drug effects