inhibits induced mucosal barrier disruption.

Background: () is a common nasal colonizer, whereas () is typically regarded a pathogenic organism in patients with chronic rhinosinusitis (CRS). This study aims to evaluate the interaction of the two bacteria .

Methods: Clinical isolates of and from sinonasal swabs, as well as primary human nasal epithelial cells (HNECs) cultured from cellular brushings of both healthy and CRS patients were used for this study. The cell-free culture supernatants of all isolates grown alone and in co-cultures were tested for their effects on transepithelial electrical resistance (TER), FITC-Dextran permeability, lactate dehydrogenase (LDH), and IL-6 and IL-8 secretion of HNECs. Confocal scanning laser microscopy and immunofluorescence were also used to visualize the apical junctional complexes. cell-free culture supernatants were also tested for antimicrobial activity and growth on planktonic and biofilm growth.

Results: The cell-free culture supernatants of 3\ strains (at 60% for reference strain and 30% concentration for clinical strains) inhibited the growth of both the planktonic reference and clinical strains significantly. The cell-free culture supernatants caused no change in the TER or FITC-Dextran permeability of the HNEC-ALI cultures, while the cell-free culture supernatants of strains had a detrimental effect. Cell-free culture supernatants of co-cultured with both the clinical and reference strains of delayed the -dependent mucosal barrier damage in a dose-dependent manner.

Conclusion: cell-free culture supernatants appear to inhibit the growth of the planktonic bacteria, and may reduce the mucosal barrier damage caused by .