Prospective observational case series evaluating middle ear fluid and tympanostomy tubes through pyrosequencing

Area of Science:

• Otolaryngology
• Microbiology
• Pediatric Medicine

Background:

• Post-tympanostomy tube otorrhea (PTTO) is a common complication.
• Granulation tissue forms in 5-13.8% of patients with tympanostomy tubes (TTs).
• Understanding microbial biodistribution in PTTO is crucial for effective treatment.

Purpose of the Study:

• To determine the biodistribution of microorganisms on TTs and middle ear fluid in pediatric patients with PTTO.
• To compare microbial findings between retained TTs with minimal otorrhea and those with active mucopurulent otorrhea and granulation tissue.

Main Methods:

• Prospective observational study of pediatric patients (6 months-16 years) with chronic PTTO.
• Analysis of TTs and middle ear fluid using DNA pyrosequencing.
• Comparison with standard culture-based diagnostics for ear fluid samples.

Main Results:

• Pyrosequencing revealed both aerobic and anaerobic bacterial populations in PTTO.
• Retained TTs with minimal otorrhea showed Staphylococcus species and normal external auditory canal (EAC) flora.
• Active mucopurulent otorrhea and granulation tissue were associated with Gram-negative facultative anaerobes like Pseudomonas and Eikenella.

Conclusions:

• Retained TTs are primarily colonized by normal EAC flora.
• Mucopurulent otorrhea and granulation tissue indicate a shift towards Gram-negative facultative anaerobes.
• Standard culture methods may not identify predominant infectious agents, highlighting the need for advanced techniques and further research.