Current Bacteriology of Suppurative Otitis

Abstract

INTRODUCTION: Antibiotic resistance has complicated the management of the draining ear. In this study, we examine the factors predisposing to resistance, as well as the role culture played in the management of these patients. MATERIALS AND METHODS: A retrospective chart review was performed on all patients with a complaint of otorrhea during a 3-year period. Demographic factors, the patients diagnosis, previous antimicrobial use, the organism isolated, the resistance pattern of the organism, the treatment instituted, the treatment changed, and the efficacy of treatment were all examined. RESULTS: Previous antibiotic use resulted in a significantly increased rate of resistance only for the diagnosis of otitis externa (p = 0.01). No other factors were found to be clinically significant. The previous use of ototopical quinolones was shown to be correlated with a significant increase in quinolone resistance (p = 0.01). Methicillin-resistant Staphylococcus aureus isolated was shown to have 60% and 33% resistance rates to clindamycin and trimethoprim/sulfamethoxazole, respectively. The overall treatment failure rate was 36% but rose to 50% for infections involving highly resistant bacteria (p = 0.01). Treatment was changed based on culture results in 21% of cases. CONCLUSION: Previous antibiotic use is correlated with increased bacterial resistance in the case of otitis externa. Highly resistant bacteria were associated with an increased rate of treatment failure. Culture plays an essential role in the management of refractory otorrhea.