[Anaerobic respiratory infection--evaluation of methods of obtaining specimens]

Anaerobic cultures were performed on various kinds of specimens obtained from 67 patients with respiratory infections. The infections consisted of 33 cases of pneumonia, 14 cases of lung abscess, 6 cases of pyothorax, 9 cases of chronic lower respiratory tract infection, and 5 cases of infection of pulmonary cyst. Specimens included bronchoscopic specimens obtained using a single tube or protected catheter brush (PCB), transtracheal aspirate, percutaneous lung aspirate, aspirate using a suction tube through the tracheostomy or intubation tube, and pleural fluid. Anaerobes were isolated in 80% of pyothorax, 43% of lung abscess, and 15% of pneumonia (42% of aspiration pneumonia), respectively. Anaerobes isolated frequently in respiratory infections included Prevotella spp., Fusobacterium spp., and Peptostreptococcus spp. In regard to the type of specimen, bronchial aspirate obtained by bronchoscopy was useful in examination of pneumonia, and was useful as percutaneous lung aspirate in examination of lung abscess. But there was discrepancy of culture results between specimens obtained by different methods in the same patient. To confirm anaerobes as pathogens in respiratory infections, it is necessary to select an appropriate method to obtain specimens and to interpret the culture results comprehensively.