One-day application of topical moxifloxacin 0.5% to select for fluoroquinolone-resistant coagulase-negative Staphylococcus
Received 10 September 2008; received in revised form 20 April 2009; accepted 21 April 2009.
Purpose
To compare selection for fluoroquinolone-resistant bacteria between 1-day and 3-day application of topical moxifloxacin 0.5%.
Setting
Department of Ophthalmology, Stanford University, Stanford, California, USA.
Methods
After investigative review board approval, patients scheduled for ocular surgery were randomized to receive topical moxifloxacin 0.5% drops 4 times a day for 1 day or 3 days preoperatively. Conjunctival cultures were obtained at baseline and after antibiotic application. Bacteria were identified and tested for resistance to a battery of antibiotic agents using the Kirby-Bauer disk-diffusion method. The differences in resistance distributions for the most commonly isolated bacteria between baseline (T0) and after antibiotic administration (T1) were compared between the 2 treatment groups.
Results
Coagulase-negative Staphylococcus (CNS) were the most common bacteria isolated at T0 and T1. At T0, the proportion of CNS isolated in the 1-day group (n = 63) that was resistant to fluoroquinolones ranged from 4% to 22% depending on the antibiotic agent tested. After 1-day treatment with moxifloxacin, the percentage of resistant bacteria increased significantly (range 13% to 67%) for all fluoroquinolones except gatifloxacin (P<.05). Resistance to gentamicin and tobramycin also increased significantly. However, patients treated for 3 days (n = 57) showed no differences in bacterial resistance rates to any antibiotic agent tested.
Conclusion
Prophylactic topical moxifloxacin 0.5% treatment starting 1 day before ocular surgery resulted in a significant increase in fluoroquinolone-resistant bacteria, while a 3-day antibiotic regimen did not select for resistant organisms.
From the Departments of Ophthalmology, School of Medicine (He, Ta, Miño de Kaspar), Stanford, California, USA, and Ludwig-Maximilians-University (Miño de Kaspar), Munich, Germany
Corresponding author: Christopher N. Ta, MD, Department of Ophthalmology, School of Medicine, 900 Blake Wilbur Drive, W3036, Stanford University, Stanford, California 94304, USA.
No author has a financial or proprietary interest in any material or method mentioned.
Presented in part at the annual meeting of the Association for Research in Vision and Ophthalmology, Fort Lauderdale, Florida, USA, May 2005.
Supported by the Hannelore-Georg Zimmermann Foundation, Munich, Germany.
ABSTRACT