Culturable Nasal Bacteria in Chronic Rhinosinusitis with Nasal Polyps: A Single-Center Observational Pilot Study

Background: Bacteria colonizing the nasal cavity contribute to mucosal homeostasis, and altered sinonasal bacterial communities have been associated with chronic rhinosinusitis with nasal polyps (CRSwNP). Whether routine, culture-based microbiology can distin- guish the cultivable bacterial profile of CRSwNP patients from that of controls remains unclear. Methods: In this single-center observational pilot study, middle-meatus swabs from 30 patients with CRSwNP and 30 controls were cultured on four media, and isolates were identified with the VITEK 2 system. For each species, presence or absence per subject was compared between groups using Fisher’s exact test with Benjamini–Hochberg correc- tion for multiple comparisons; the number of cultivable species per subject was compared with the Mann–Whitney test. Results: The two groups were comparable in age and sex. Patients yielded more cultivable bacterial species per subject than controls (mean 4.4 vs. 2.9; Mann–Whitney p < 0.001). Several species were numerically more frequent in patients (e.g., Staphylococcus hominis, S. lugdunensis) and others in controls (e.g., S. epidermidis, S. aureus), but no individual species difference remained significant after correction. Conclu- sions: Using routine culture, CRSwNP was characterized chiefly by a higher number of cultivable bacterial species, whereas individual species differences were not statistically robust. These hypothesis-generating findings warrant confirmation in larger, sequencing- based studies.