Acute bacterial rhinosinusitis is a clinical diagnosis that does not require proof of a culture-identified pathogen. When patients meet criteria for uncomplicated ABRS, empiric antibiotic selection should be based on typical causative pathogens (i.e. Streptococcus pneumoniae, Hemophilus influenza, Moraxella catarrhalis, and Staphylococcus aureus), local bacterial resistance patterns, and patient factors. Nasal swabs are contaminated by normal nasal flora and results correlate poorly with causative pathogens in rhinosinusitis. In many hospitals, a nasal swab will only be processed to report on the presence or absence of S. aureus, rather than a full culture for speciation. In situations where cultures are required, such as intraorbital or intracranial complications, endoscopically-guided culture of the middle meatus or a maxillary sinus aspirate are the preferred methods for obtaining samples of the causative pathogen.
Sources:
Desrosiers M, et al. Canadian Clinical Practice Guidelines for Acute and Chronic Rhinosinusitis. [Internet]. 2011 February [cited 2018 July].
Chow AW, et al. IDSA Clinical Practice Guideline for Acute Bacterial Rhinosinusitis in Children and Adults. Clin Infect Dis. 2012;54(8):e72-e112. PMID: 22438350.