Lessons learned from conventional animals: Encouragement to use specific-pathogen-free animals

Area of Science:

• Regenerative Medicine
• Otolaryngology
• Translational Research

Background:

• Experimental rabbits are vital models for human disease research.
• Middle ear mucosal regeneration studies require healthy animal models.
• Microbiological contamination can compromise research integrity.

Purpose of the Study:

• To evaluate a novel method for middle ear mucosal regeneration using autologous cultured nasal mucosal epithelial cell sheets in rabbits.
• To assess the impact of microbiological contamination on wound healing in rabbit middle ear mucosa.
• To emphasize the importance of specific-pathogen-free (SPF) animals in surgical intervention studies.

Main Methods:

• Development of a novel technique for middle ear mucosal regeneration using autologous cultured nasal mucosal epithelial cell sheets.
• Evaluation of wound healing in experimental rabbit middle ear mucosa.
• Comparison of outcomes between non-specific-pathogen-free (non-SPF) and specific-pathogen-free (SPF) rabbits, including microbiological monitoring.

Main Results:

• Non-SPF rabbits without microbiological monitoring developed otitis media due to *Pasteurella multocida* contamination.
• SPF rabbits remained free of otitis media, demonstrating healthier conditions.
• The contamination issue in non-SPF rabbits significantly affected the mucosal regeneration study results.
• Switching to SPF rabbits resolved the contamination problem and improved study reliability.

Conclusions:

• Vigilant microbiological monitoring and the use of SPF animals are essential for surgical intervention studies in experimental rabbits.
• Ensuring animal health is critical for obtaining accurate and reproducible results in translational research.
• The study highlights the necessity of SPF status to prevent confounding factors like otitis media in regenerative medicine research.