The bacteriology of chronic rhinosinusitis and the pre-eminence of Staphylococcus aureus in revision patients

Background: The role of bacteria in the etiopathogenesis of chronic rhinosinusitis (CRS) remains an area of interest. The impact of surgery and factors such as the presence of polyps, asthma, and aspirin sensitivity on the bacterial state are poorly understood. To determine the effect of these factors, this study examines the culture results from a large cohort of CRS patients. Methods: This retrospective study used the culture results from 513 CRS patients, which were analyzed for species growth and compared to factors such as previous surgery, presence of polyps, aspirin sensitivity, and asthma. Univariate and multivariate logistic regression models were used for statistical analysis. Results: Eighty-three percent (83%) of patients had a positive culture result. The average number of isolates detected per patient was 0.95. S. aureus was the most frequently cultured organism (35%), followed by P. aeruginosa (9%), Haemophilus spp. (7%), and S. pneumonia (5%). Revision patients were more likely to grow S. aureus (p = 0.001), P. aeruginosa (p = 0.044) and have a positive culture (p = 0.001). Asthma was correlated with a positive culture (p = 0.039). No difference was determined between polyp and nonpolyp patients for any of the bacterial outcomes. Conclusion: This study highlights important factors in the bacteriology of CRS patients. S. aureus was the most prevalent species identified in our cohort, followed by P. aeruginosa. S. aureus rates of isolation were also significantly higher in patients undergoing revision surgery. No association was found between the presence of nasal polyposis and culture rates.