Coagulase-negative Staphylococcus culture in chronic rhinosinusitis.

Background: Coagulase-negative Staphylococcus (CoNS) is commonly isolated from patients with chronic rhinosinusitis (CRS). However, the role of CoNS in CRS remains controversial. We aimed to determine the association between positive CoNS culture at functional endoscopic sinus surgery (FESS) and CRS severity.

Methods: Adult CRS patients who underwent FESS between October 1, 2007 to December 31, 2011 were recruited. Patient demographics, disease characteristics, medication use, Lund-Mackay computed tomography (CT) scores, and 22-item Sino-Nasal Outcome Test (SNOT-22) scores were collected at baseline before FESS. Intraoperative cultures were obtained in a standard manner. Patients were placed into 2 groups based on culture findings: patients with CoNS as the sole positive culture result and patients with all other positive culture results, including CoNS, as part of a polymicrobial culture.

Results: A total of 376 CRS patients met the criteria; 106 patients (28%) had CoNS as their only isolate, 260 (69%) had other positive cultures, and 10 (3%) had no bacterial growth. Compared to patients with other positive cultures, patients with the sole result of CoNS were significantly less likely to have a history of FESS (52% vs 65%, p = 0.019), nasal polyps (50% vs 65%, p = 0.006), and had a better Lund-Mackay CT score (11.95 vs 14.18, p = 0.020). After adjusting for all factors in the multiple logistic regression model, CoNS as the sole positive culture result was independently associated with having no history of FESS (odds ratio [OR] = 0.45; 95% confidence interval [CI], 0.22 to 0.94; p = 0.034).

Conclusion: Positive intraoperative CoNS cultures alone do not result in increased CRS disease burden by objective or subjective measures as compared to patients with other bacterial or polymicrobial culture isolates.