Microbiology of nosocomial sinusitis in mechanically ventilated children

Objective: To assess the bacteriology of nosocomial sinusitis in mechanically ventilated children. Method: Retrospective review of sinus aspirate specimens obtained from 20 children with nosocomial sinusitis. The specimens were processed for aerobic and anaerobic bacteria. Results: A total of 58 isolates (2.9 per specimen), 30 aerobic or facultative (1.5 per specimen) and 28 anaerobic (1.4 per specimen), were recovered. Aerobes only were present in 8 patients (40%), anaerobes only in 5 (25%), and mixed aerobic and anaerobic flora in 7 (35%). The predominant aerobes were Pseudomonas aeruginosa (6 isolates), Staphylococcus aureus (5 isolates), Escherichia coli (3 isolates), and Klebsiella pneumoniae (3 isolates). The predominant anaerobes were Peptostreptococcus species (8 isolates), Prevotella species (6 isolates), and Fusobacterium species (4 isolates). Forty-one beta-lactamase bacteria were recovered from 14 specimens (70%). Thirty isolates similar to the sinus isolates were also recovered from the trachea, 6 from blood culture specimens, and 6 from other sites. Anaerobes were more commonly isolated from sinus aspirate samples obtained after 18 days of mechanical ventilation (21 vs 7, P<.05 by chi(2)). Conclusion: This study demonstrates the polymicrobial aerobic-anaerobic flora of nosocomial sinusitis in mechanically ventilated children.