Microbiology of Rhinosinusitis and Antimicrobial Resistance

Acute rhinosinusitis (ARS) is the inflammation of the nasal mucous membrane and can be separated into acute viral and acute bacterial rhinosinusitis. It is frequently observed after viral rhinitis or common cold. Viral, post-viral, and acute bacterial ARS (ABRS) display significantly similar clinical presentation and inflammatory mechanism. Viral infection of the sinus cavity can cause numerous changes such as post-viral inflammation and epithelial damage, which enhance the susceptibility to bacterial infection. The most common virus families that cause ARS are coronavirus and rhinovirus. Approximately 50% of common colds are caused by the human rhinovirus. Other viral offenders include parainfluenza, influenza, respiratory syncytial virus (RSV), adenovirus, and enterovirus. The most widely recognized bacteria in ABRS are S. pneumonia, H. influenza, and M. catarrhalis and S. aureus, while other species and anaerobic bacteria may also contribute to the infection (Payne and Benninger, Clin Infect Dis 45(10):e121–7, 2007; Anonymous, Otolaryngol Head Neck Surg 130(1 SUPPL):1–45, 2004; Brook, Arch Otolaryngol Head Neck Surg 128(5):583–5, 2002). Interestingly, Payne and colleagues performed a meta-analytic study on reports about the microbiology of ABRS, which evaluated the most common bacterial occurrence within the sinus. S. aureus is commonly associated with the pathogenesis of sphenoid sinusitis. The 7-valent pneumococcal vaccine was presented in the United States in 2000 and aided in the reduction of the recovery rate for S. pneumoniae and the increase in the rate of H. influenza. Chronic rhinosinusitis (CRS) vary in comparison to ARS. Bacteria that have been recorded in many samples acquired by endoscopy or sinus puncture in CRS patients are Staphylococcus aureus (both MSSA and MRSA), Staphylococci (coagulase-negative) (SCN), H. influenza, M. catarrhalis, S. pneumonia, S. intermedius, P. aeruginosa, N. species, and other anaerobic bacteria. In this chapter, microbiology of rhinosinusitis and antimicrobial resistance are discussed.