Pneumonia in mechanically ventilated children.

The quantitative aerobic and anaerobic microbiology of bronchial aspirates, obtained using protective brush catheters, from 10 children with ventilator-associated pneumonia, is presented. Aerobic or faculative organisms only were isolated in 1 child, anaerobic bacteria only in 3, and aerobic mixed with anaerobic bacteria in 6. There were 10 aerobic or faculative and 17 anaerobic isolates. The predominant aerobes were Pseudomonas aeruginosa (2 isolates) and Klebsiella sp. (2). The predominant anaerobes were pigmented Prevotella and Porphyromonas species (5), Peptostreptococcus sp. (4), Fusobacterium sp. and B. fragilis group (2). A total of 10 beta-lactamase-producing aerobic and anaerobic bacteria were isolated in 8 patients. All patients except 1 responded to antimicrobial therapy directed against the recovered isolates. These data highlight the polymicrobial aerobic-anaerobic flora isolated from pulmonary specimens of patients with ventilator-associated pneumonia.