What Should be the Antibiotic Preference in the Treatment of Bacterial Conjunctivitis?

Summary Purpose: To investigate the pathogens associated with bacterial conjunctivitis and the in vitro antibiotic sensitivities of these bacteria. Material and Method: Forty-seven (27 female, 20 male) patients with a mean age of 43.7±26.4 (range: 1-84) years, who referred to our out-patient clinic with complaints of burning sensation, stringy discharge and hyperemia between December 2008 and March 2010, who were diagnosed with acute bacterial conjunctivitis, and had no history of any systemic or topical antibiotic use were included in the study. Samples were taken from both eyes using cotton swabs, cultured onto chocolate and blood agar, and prepared for Gram staining. The identification of organisms was performed by Vitek2 compact system (bioMerieux, France). Antibiograms were evaluated according to the Clinical and Laboratory Standards Institute (CLSI) criteria by disc diffusion method. Results: Twenty-nine of 47 (61.7%) samples were culture-positive. The most common isolated bacteria were coagulasenegative staphylococci (16 cases, 55%). For them, the most sensitive antibiotics, given in decreasing order, were as follows: vancomycin (100%, 21/21), netilmicin (95.7%, 22/23), chloramphenicol (92.6%, 25/27) and tobramycin (91.3%, 21/23). Fluoroquinolones were relatively less sensitive: ofloxacin (75%, 21/28), moxifloxacin (75%, 18/24), ciprofloxacin (73.1%, 19/26). Discussion: Netilmicin, chloramphenicol and tobramycin were found to be more sensitive compared to fluoroquinolones in the treatment of bacterial conjunctivitis. Using these antibiotics as an empirical treatment, taking conjunctival culture of particular cases prior to treatment, and antibiotic switching according to antibiogram will be the most reasonable approach in case of no response to treatment. (Turk J Ophthalmol 2010; 40: 354-8)