Potential conflict of interest: P.J.W. receives royalties from Medtronic and is a consultant for Neilmed.
Bacterial-induced epithelial damage promotes fungal biofilm formation in a sheep model of sinusitis
Article first published online: 10 JAN 2013
© 2013 ARS-AAOA, LLC
International Forum of Allergy & Rhinology
Volume 3, Issue 5, pages 341–348, May 2013
How to Cite
How to Cite this Article: Bacterial-induced epithelial damage promotes fungal biofilm formation in a sheep model of sinusitis. Int Forum Allergy Rhinol, 2013; 3:341–348., , , , ,
- Issue published online: 17 MAY 2013
- Article first published online: 10 JAN 2013
- Manuscript Accepted: 17 NOV 2012
- Manuscript Revised: 29 OCT 2012
- Manuscript Received: 27 MAY 2012
- chronic rhinosinusitis;
- fungal sinusitis;
- epithelial damage fungus;
Fungal biofilms have been discovered in chronic rhinosinusitis (CRS) patients, but factors contributing to their establishment are obscure. A recent animal study showed bacterial co-inoculation was required. We examine the role of 4 bacterial species and a cilia toxin on fungal biofilm formation in a sheep sinusitis model. The importance of epithelial integrity on fungal biofilm formation is also examined.
Forty-eight frontal sinuses were inoculated with Aspergillus fumigatus alone, with 1 of 4 bacteria, or a cilia toxin. Bacterial and fungal biofilm was determined using confocal scanning laser microscopy. Inflammation and cilia integrity were assessed using light microscopy and transmission electron microscopy, respectively.
No fungal biofilm formed when inoculated alone. Florid fungal biofilm developed in more than 75% of sinuses associated with bacterial biofilm of all species, except Haemophilus influenzae, which failed to establish bacterial biofilm. Fungal biofilm also established in association with cilia toxin. Significant cilial damage was incited by all bacterial biofilms and cilia toxin, and was associated with fungal proliferation. Fungal biofilm formation did not significantly increase mucosal inflammation or epithelial damage over that caused by the bacteria or cilia toxin alone.
Bacterial biofilms cause sinonasal mucosal inflammation and epithelial injury, which provides conditions appropriate for fungal biofilm proliferation. The role of cilia in sinonasal mucosal defense against fungal organisms has been demonstrated. Without such an insult, fungal biofilms fail to proliferate in occluded sinuses. Improving cilial recovery postoperatively and treating bacterial biofilms may be key factors in reducing recalcitrance in allergic fungal rhinosinusitis patients.