Microbiology of recurrent acute rhinosinusitis

OBJECTIVE: We undertook to evaluate the microbiology of recurrent acute rhinosinusitis. METHODS: Repeated aspirations of maxillary sinus secretions by endoscopy were performed in eight patients over a period of 98 to 185 days. RESULTS: Bacteria were recovered for all 25 aspirates. A total of 31 isolates-14 Streptococcus pneumoniae, 11 Haemophilus influenzae, 5 Moraxella catarrhalis, and 1 Staphylococcus aureus-were recovered. The organism persisted in consecutive cultures in 13 instances and were eliminated in 8, and new organisms emerged in 6 instances. An increase in antimicrobial resistance was noted in 5 instances (3 in S. pneumoniae and 2 H. influenzae). CONCLUSIONS: This study illustrates the microbial dynamics of recurrent acute rhinosinusitis, with the changes in microbial findings and increased bacterial resistance that occurs over time.