Microbiology of acute exacerbation of chronic sinusitis

Objectives: We undertook to evaluate the microbiology of acute exacerbation of chronic sinusitis (AECS). Methods: Repeated aspirations of maxillary sinus secretions by endoscopy were performed in 7 patients over a period of 125 to 242 days. Results: Bacteria were recovered for all 22 aspirates, and the number of isolates was between 2 and 4. A total of 54 isolates were isolated: 16 aerobic and facultative bacteria and 38 anaerobic bacteria. The aerobic bacteria were Haemophilus influenzae (7 isolates), Streptococcus pneumoniae (3), Moraxella catarrhalis (3), Staphylococcus aureus (2), and Klebsiella pneumoniae (1). The anaerobic bacteria included pigmented Prevotella and Porphyromonas spp (19), Peptostreptococcus spp (9), Fusobacterium spp (8), and Propionibacterium acnes (2). A change in the types of isolates was noted in all consecutive cultures obtained from the same patients as different organisms emerged and previously isolated bacteria were no longer recovered. An increase in antimicrobial resistance was noted in 6 instances. Conclusions: This study illustrates the microbial dynamics of AECS in which anaerobic and aerobic bacteria prevail, and highlights the importance of obtaining cultures from patients with AECS for guidance in selection of proper antimicrobial therapy.