Antimicrobial Resistance of Pseudomonas Aeruginosa from Otorrhea of Chronic Suppurative Otitis Media Patients

Objective: Pseudomonas aeruginosa (PA) is one of the most common pathogenic bacteria in hospital-acquired infections and chronic suppurative otitis media (CSOM). Drug resistance of PA has been found to increase along with its frequency. We sought to determine the isolation rate and antibiotic susceptibility patterns of PA from otorrhea of CSOM and general clinical samples.

Study Design: Cross-sectional study.

Setting: CSOM patients had been treated at six hospitals. General clinical samples were from a single tertiary teaching hospital.

Subjects And Methods: We assessed 1103 CSOM patients treated at six hospitals and 3177 clinically pustular samples from one tertiary teaching hospital in Korea from 2004 to 2008.

Results: PA was the organism most frequently isolated from otorrhea patients (25.8%), with the annual isolation rate remaining constant over time. In contrast, PA was isolated from 11.2 percent of general clinical samples, and the annual PA isolation rate from general clinical samples decreased over time. The PA isolation rate from otorrhea was significantly higher than that from general clinical samples. PA isolates from both otorrhea and general clinical samples showed similar antibiotic susceptibility patterns, but susceptibilities to a few antibiotics were quite different. Although the annual PA isolation rate from general clinical samples from a single hospital tended to decrease over time, the rate from otorrhea samples did not.

Conclusion: Changes in isolation rate and susceptibility patterns of PA suggest the need for regular surveillance of PA isolates, including antibiotic susceptibility tests, to choose empirical antibiotics and reduce the spread of multidrug-resistant strains.