Antibiotic-resistant bacteria in pediatric chronic sinusitis

Background. Limited information exists on emerging bacterial resistance patterns in pediatric chronic sinusitis. Methods. A retrospective review (1995 to 1998) of the aerobic microbiology of chronic sinusitis in children at a tertiary care children's hospital was conducted. One hundred nineteen children (mean age, 4.9 years) with maxillary sinusitis of >8 weeks duration and no known immunodeficiency or cystic fibrosis who underwent antral irrigation were included. Results. One hundred sixty-one of 240 (67%) aerobic cultures were positive, yielding 274 isolates, Eighty-eight positive cultures were polymicrobial. The most frequent isolates were non-typable Haemophilus influenzae (24%), Streptococcus pneumoniae (19%), Moraxella catarrhalis (17%), coagulase-negative Staphylococcus (6%), alpha-streptococci (6%), diphtheroids (5%), Staphylococcus aureus (3%) and Neisseria spp, (3%). Rates of nonsusceptibility of Streptococcus pneumoniae were 64% for penicillin (24% high grade resistance), 40% for cefotaxime, 18% for clindamycin and 0% for vancomycin. Rates of nonsusceptibility of S. pneumoniae did not change significantly during the study period. Thirty-nine percent of H. influenzae isolates were beta-lactamase-positive and 44% were non-susceptible to ampicillin (41% high grade resistance). Beta-lactamase positivity of H. influenzae decreased during the study period (P = 0.06). All M. catarrhalis isolates tested were beta-lactamase-positive. Conclusion. This study indicates that the aerobic pathogens in pediatric chronic sinusitis include bacteria typical of acute sinusitis as well as organisms more characteristic of chronic disease. Moreover it highlights the significant role of antibiotic-resistant aerobes, including multiply resistant S. pneumoniae, in pediatric chronic sinusitis.