Abstract
Abstract
Background
The role of fungi in the spectrum of chronic rhinosinusitis (CRS) is poorly understood. Fungal biofilms have recently been discovered in CRS patients. We have developed an animal model for the investigation of sinonasal fungal biofilms. The role of type I hypersensitivity and pathogenic bacteria is presented.
Methods
Thirty sheep were sensitized with fungal antigens—
Aspergillus fumigatus
and
Alternaria alternata
, or control. Endoscopic surgery was performed to expose both frontal sinus ostia—1 was occluded. Fungi with or without
Staphylococcus aureus
were inoculated into the sinus. Skin‐prick tests assessed for fungal allergy. Fungal and
S. aureus
biofilms, histology, and culture rates were assessed.
Results
Forty‐five percent of experimental sheep were sensitized to fungal antigen. Only 1 sinus inoculated with fungus developed minimal fungal biofilm. Eighty percent developed fungal biofilm when
S. aureus
was co‐inoculated. The presence of hypersensitivity to fungus was not related to fungal biofilm development.
Conclusion
Significant fungal biofilm only occurred when
S. aureus
was the co‐inoculum. Hypersensitivity was not requisite. The relationship of
S. aureus
to fungal biofilms is of great clinical interest. Fungi may be opportunistic pathogens that simply require inflamed mucosa with weakened innate defenses; alternatively, a cross‐kingdom synergy could be contributing to fungal proliferation. © 2011 ARS‐AAOA, LLC.