Three Day Application of Topical Ofloxacin Does Not Induce Fluoroquinolone–Resistant Coagulase–Negative Staphylococci

Abstract

Abstract: : Purpose: To determine whether a three–day preoperative application of topical 0.3% ofloxacin for intraocular surgery prophylaxis increases the selection of resistant conjunctival bacterial flora compared to a one hour application. Methods:One hundred and eighty–two eyes of 170 patients scheduled for intraocular ocular surgery were prospectively randomized into control (n = 99) or study group (n = 83) Conjunctival smears were collected from all patients at baseline (before application of antibiotics or iodine) prior to surgery (T0), and again upon arrival to the surgery center (T1). At T1, eyes in the control group have not been treated with antibiotics, whereas eyes in the study group were treated with ofloxacin for three days. All bacterial growth was identified and antibiotic susceptibilities determined by the Kirby–Bauer disc–diffusion tests. Results:Among the 146 bacteria isolated from all patients at baseline, 101 were coagulase–negative Staphylococcus. 

Table 1. Antibiotic susceptibility pattern of coagulase–negative staphylococci to fluoroquinolones tested. *Numerator indicates number of samples susceptible or resistant to the antibiotics. *Denominator indicates total number of samples. †percentage of bacteria tested that were susceptible or resistant to the antibiotic tested. There were no statistical differences regarding antibiotic susceptibility between the control and study groups at baseline (T0) or at T1 (P = 0.41 and 0.33, respectively). For the study group, the absolute number of resistant bacteria decrease from baseline (T0) to after treatment (T1) for all antibiotics tested. Conclusions: A three day regimen of topical ofloxacin does not increase the number of resistant bacteria isolated from the conjunctiva of patients undergoing intraocular surgery.

Keywords: antibiotics/antifungals/antiparasitics • endophthalmitis • bacterial disease