Objective: To investigate changes in Pseudomonas aeruginosa (PA) and methicillin-resistant Staphylococcus aureus (MRSA) and their antibiotic sensitivities over 13 years in patients diagnosed with chronic suppurative otitis media (CSOM).
Materials and methods: The current study reports on a retrospective analysis of the outcomes of 2256 outpatients who visited the Department of Otorhinolaryngology clinics of 3 tertiary medical centers and who were diagnosed with chronic otitis media (COM) or chronic cholesteatomatous otitis media (CCOM) from January 2001 to December 2013. Aural discharge was collected from each patient. Infectious bacteria were identified, and their antibiotic sensitivities were determined.
Results: The most frequent age range of patients diagnosed with CSOM was 41 to 50 years. In patients aged more than 30 years, CSOM was more frequent in females than in males, whereas in those aged less than 30 years, it was more frequent in males. Regardless of age, the isolated MRSA strains showed high sensitivity to vancomycin, teicoplanin, and trimethoprim/sulfamethoxazole, whereas the isolated PA strains showed high sensitivity to cefepime, amikacin, and ceftazidime. The isolation rate of MRSA in patients with CSOM slightly decreased over the 13-year study period; however, PA resistance to quinolones and aminoglycosides showed a tendency to increase.
Conclusion: Bacteria isolated from patients with CSOM showed little change between 2001 and 2013, whereas their antibiotic resistance showed changes; in particular, increased PA resistance to quinolones was observed. Empirical antibiotic treatment can lead to bacterial resistance, and changes in antimicrobial agents commonly used to treat CSOM should be considered.