Identification and antimicrobial susceptibility of acute external otitis microorganisms

Summary Acute external otitis is a polymicrobial infectious disease. Aim The purpose of this study was to isolate, identify and determine the Antimicrobial susceptibility of organisms causing otitis externa (OE). Methods twenty-seven swabs were taken from the ears of 27 patients with OE for culture and 22 microorganisms were isolate to evaluate sensitivity. In vitro susceptibility tests were performed by agar diffusion disk and results were interpreted according to Clinical Laboratory Standards. Results 10 Ear cultures were positive for S. aureus , 8 for P. aeruginosa , 5 for P. aeruginosa and S. aureus and 4 for fungal organisms ( Candida albicans e C. Krusei ). Gentamicin and quinolones were active against all bacteria tested and significant resistance to amoxicillin/clavulanate was observed. The tested species of Candida had been sensitive to amphothericin B, nystatin, fluconazole and clotrimazole and resistant to miconazole. Conclusion Acute external otitis is a polymicrobial infection and proper knowledge regarding microorganism etiology and susceptibility will contribute to rational antibiotic usage and treatment success.