Abstract
Purpose::
To determine the antibiotic susceptibility patterns of conjunctival bacterial flora isolated preoperatively from patients undergoing cataract, glaucoma, and corneal surgeries.
Methods::
Eighty-eight eyes (both surgical eyes and contralateral eyes) from 44 patients scheduled for eye surgeries were enrolled over a 6-month period from June 2006 to November 2006. Conjunctival cultures were obtained on the day of the preoperative visit. Bacterial isolates were tested for susceptibility to 23 antibiotics using the Kirby-Bauer disc-diffusion technique.
Results::
Among the 88 eyes studied, 24 (27%) showed no bacterial growth. Among the 25 pairs of eyes that both had bacterial growth, 6 had identical antibiotic susceptibility patterns, and another 8 pairs had patterns that differed in 3 or fewer antibiotics. Of the bacteria isolated from the 30 surgical eyes with bacterial growth, 90% were gram-positive cocci (coagulase-negative staphylococci or Staphylococcus aureus), 6% were Streptococcus, and 3% were gram-negative rods. Greater than 90% of the bacteria were susceptible to gatifloxacin, imipenem, amikacin, gentamicin, tobramycin, or vancomycin. Between 70% and 90% were susceptible to minocycline, ciprofloxacin, norfloxacin, ofloxacin, levofloxacin, moxifloxacin, meropenem, neomycin, tetracycline, or chloramphenicol. Less than 40% were susceptible to mezlocillin, oxacillin, or penicillin.
Conclusions::
Preoperative conjunctival flora are most sensitive to aminoglycosides, fluoroquinolones, carbapenems, and vancomycin. Penicillin and its analogs are the least effective.
Clinical Trial::
www.clinicaltrials.gov NCT00350363
Keywords: antibiotics/antifungals/antiparasitics • bacterial disease