Correlation between culture-identified bacteria in the middle nasal meatus and CT score in patients with chronic rhinosinusitis

The aim of this study was to compare bacteriological findings in the middle nasal meatus in patients with chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP) and healthy controls, and to investigate the correlation between the prevalence of culture-identified bacteria and the severity of sinus disease. Bacterial culture was performed using a swab from the middle nasal meatus under endoscopic control in 72 patients with CRSwNP, 25 patients with CRSsNP and 59 healthy controls. Computed tomography (CT) scans were graded for severity using the Lund–Mackay scoring system. Patients with more severe forms of CRS with and without nasal polyps had significantly higher rates of pathogenic bacteria in the middle nasal meatus compared with patients with lower CT scores of the paranasal sinuses. There were no significant differences in bacterial species among CRSwNP, CRSsNP and control patients. These results demonstrate, for the first time, that colonization by pathogenic bacteria in patients with CRSwNP and CRSsNP is associated with a more severe form of the disease, as assessed by a pre-operative CT scan of the paranasal sinuses. The results suggest a role for bacterial infection in the pathogenesis of CRS. However, bacteria do not appear to play a role in the development of nasal polyposis in patients with CRS.