Changes in bacteriology of discharging ears.

Area of Science:

• Microbiology
• Infectious Diseases
• Otolaryngology

Background:

• Otorrhoea, or discharging ear, is a common condition requiring bacteriological investigation.
• Understanding the causative pathogens and their antibiotic resistance patterns is crucial for effective treatment.
• Previous studies indicated Pseudomonas aeruginosa as a dominant pathogen in Taiwanese otorrhoea cases.

Purpose of the Study:

• To prospectively investigate the bacteriology of otorrhoea in Taiwanese outpatients.
• To determine the prevalence of Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus (MRSA) in ear infections.
• To assess the antibiotic susceptibility profiles of isolated pathogens, particularly MRSA.

Main Methods:

• Prospective bacteriological study of 161 outpatients with otorrhoea at a Taiwanese teaching hospital.
• Isolation and identification of bacterial pathogens from ear discharge samples.
• Antimicrobial susceptibility testing for recovered isolates, with a focus on MRSA.

Main Results:

• A total of 177 bacterial isolates were recovered, with Staphylococcus aureus (43.5%) being more prevalent than previously reported.
• Pseudomonas sp. was the most common non-Staphylococcus aureus pathogen (28.8%).
• Community-acquired MRSA infections were found in 13.7% of patients, indicating a rising problem in acute otitis externa, granular myringitis, and chronic otitis media.

Conclusions:

• Staphylococcus aureus, including MRSA, has emerged as a significant pathogen in Taiwanese otorrhoea cases.
• MRSA isolates demonstrated high susceptibility to vancomycin, teicoplanin, fusidic acid, and minocycline.
• Further research is recommended to evaluate MRSA susceptibility to ofloxacin.