Find in Library

Chronic rhinosinusitis (CRS) is characterized by sinonasal mucosal inflammation. <i>Staphylococcus aureus (S. aureus)</i> is associated with severe CRS phenotypes. Different animal models have been proposed to study the association of CRS and <i>S. aureus</i>. However, current animal models are expensive due to the use of large animals, have high barriers to ethics approval, or require invasive surgical intervention, necessitating a need for a model that can overcome these limitations. This study aimed at establishing a reliable and efficient rat lymphoplasmacytic inflammatory model for rhinosinusitis. Sprague Dawley rats received a daily intranasal application of 20 μL of saline, <i>S. aureus</i> CI-182 exoprotein (250 μg/mL), or exoprotein CI-182 in combination with <i>S. aureus</i> clinical isolate (CI-908 or CI-913) 10⁸ colony-forming unit (CFU)/mL. The rats’ sinuses were harvested at 1 and 2 weeks post-intervention. The CFU and histopathologic examination of inflammation were evaluated. <i>S. aureus</i> clinical isolates CI-908 or CI-913 in combination with the exoprotein (CI-182) had higher CFUs and caused persistently higher inflammation at both the 1 and 2-week post-intervention compared to the exoprotein and saline group. The observed inflammatory cell type was lymphoplasmacytic. This study provided evidence that the combination of a <i>S. aureus</i> exoprotein with <i>S. aureus</i> induces inflammation that persists for a minimum of two weeks post-intervention. This model is the first known animal model to create the lymphoplasmacytic inflammation subtype seen in CRS patients. This offers a cost-effective, accessible, non-invasive, and easy-to-replicate model to study the causes and treatment of such inflammation.