Biofilm Exoproteins From <i>Staphylococcus</i> Species Impede Re‐Epithelialization of Nasal Epithelial Cells During Wound Healing and Cease Ciliary Beat Frequency

INTRODUCTION: Chronic rhinosinusitis (CRS) is an inflammatory disease with many different contributing factors, including bacterial infection. CRS patients are typically managed with medical therapies; however, these treatments frequently fail, leaving surgery as the only viable option. Despite surgical intervention, patients may experience ongoing clinical manifestations of inflammation and infection, frequently associated with Staphylococcus species colonization. This study explored the influence of Staphylococcus on the wound healing process and ciliary function in vitro. METHODS: Exoproteins were extracted from biofilm forms of 15 Staphylococcus isolates obtained from five patients (4 CRS and 1 control patient), each colonized by Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus lugdunensis. Human nasal epithelial cells (HNECs) were cultured in monolayers for wound healing assays and at an air-liquid interface (ALI) for ciliary beat frequency measurements. Wound closure, cytotoxicity, interleukin-6 (IL-6), and reactive oxygen species (ROS) release were measured after 30 h post-wound creation. RESULTS: Biofilm exoproteins from all three Staphylococcus species hindered the re-epithelialization of HNECs at 5 and 10 µg/mL with S. aureus exoproteins having significantly stronger effects on impairing wound closure compared to S. lugdunensis exoproteins. S. aureus exerted the most pronounced cytotoxic effect compared to the control. Furthermore, all Staphylococcus species reduced ROS release by HNECs while S. epidermidis and S. lugdunensis induced higher IL-6 levels compared to control. In HNEC-ALI cultures, ciliary beat frequency was significantly reduced by all staphylococci 5 h after application of exoproteins. CONCLUSION: Staphylococcal biofilm exoproteins hindered mucociliary function and re-epithelialization of the nasal epithelium, caused cytotoxicity, elicited inflammation, and concurrently reduced ROS release.