Purpose: To determine the antibiotic susceptibility of preoperative conjunctival bacterial flora.
Design: In vitro study.
Methods: Antibiotic susceptibility of conjunctival bacterial strains isolated from 164 patients undergoing intraocular surgery was determined using the Kirby-Bauer disk-diffusion technique.
Results: Among the 162 bacteria isolated, 124 (76%) were coagulase-negative staphylococci (CNS), with 2% resistant to gatifloxacin and moxifloxacin, and none were resistant to vancomycin or minocycline. Other bacteria isolated were 19 Staphylococcus aureus (S. aureus), 8 Streptococcus Group D, and 11 gram-negative rods. Most S. aureus (>85%) were susceptible to all antibiotics except for the penicillin and macrolide groups. No streptococci were resistant to gatifloxacin, levofloxacin, moxifloxacin, mezlocillin, imipenem, or vancomycin. None of the gram-negative rods were resistant to the fluoroquinolones. Approximately one half of all bacteria were resistant to erythromycin. One in three patients harbored multi-resistant bacteria (resistant to > or = five antibiotics).
Conclusions: Newer-generation fluoroquinolones provide excellent broad-spectrum coverage against conjunctival bacterial flora.