Bacteriological findings and antimicrobial susceptibility in chronic sinusitis with nasal polyp

Conclusions. We recommend amoxacillin/ clavulanate, cephalosporins and macrolides rather than penicillin as the first-line drug in chronic sinusitis with nasal polyps. In cases where there is no improvement of symptoms, cultures should be taken from the middle meatus, followed by appropriate selection of second-line antibiotics according to the sensitivity test results. Objective. To investigate the causative bacteria and the antimicrobial susceptibility in patients with chronic sinusitis and nasal polyps in Korea. Materials and methods. The bacteriology and antimicrobial susceptibility of maxillary sinus aspirates from 81 patients were evaluated. Results. Aerobes were isolated from 58.0% of the cultures from the middle meatus and from 48.1% of those from the maxillary sinus. Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pneumoniae were the most prevalent aerobic pathogens. Anaerobes were isolated from 8.6% of the cultures from the middle meatus and from 18.5% of the cultures from the maxillary sinus. The predominant anaerobic organisms were Prevotella and Peptostreptococcus in adults but none of them were cultured in children. A high rate of concordance of the middle meatus and maxillary sinus was noted. Monomicrobial infection was most commonly observed. Ampicillin-resistant H. influenzae isolates were cultured in 46% of the cases. Penicillin resistance rates were 93% for Staph. aureus; 25% of Strep. pneumoniae were intermediate and 25% were resistant.