title: Bacteriology of the lower respiratory tract as determined by fiber-optic bronchoscopy and transtracheal aspiration.
abstract: For assessment of the validity of cultures of tracheobronchial secretions and exudates (TBSE) obtained by fiber-optic bronchoscopy, the aerobic and anaerobic flora of expectorated saliva and TBSE obtained by fiber-optic bronchoscopy from nine healthy volunteers and eight patients were compared with those obtained by fiber-optic bronchoscopy as well). Normal volunteers yielded both aerobic and anaerobic bacteria in amounts usually less than 104.5 colony-forming units (cfu)/ml in TBSE obtained by fiberoptic bronchoscopy. In patients with chronic bronchitis, 42 isolates of aerobic bacteria (104-105.5 cfu/ml) and only 10 isolates of anaerobes (usually less than 104 cfu/ml) were reovered from 15 samples obtained by trantracheal aspiration. The data lead to the conclusion that low-level contamination (less than or equal to 104 cfu/ml) with oral flora is common in TBSE obtained by fiber-optic bronchoscopy. A single potential pathogen in numbers of greater than or equal to 105 cfu/ml may be of etiologic significance, particularly if recovered from purulent drainage material from a localized portion of the lung. Under circumstances in which quantitative bacteriology cannot be done, TBSE obtained by transtracheal aspiration will most reliably reflect the bacterial flora present in the lung.
mesh_terms: D000328:Adult; D001419:Bacteria / Q000302:isolation & purification*; D001439:Bacteroides / Q000302:isolation & purification; D001980:Bronchi / Q000382:microbiology*; D001991:Bronchitis / Q000382:microbiology; D001999:Bronchoscopy; D002908:Chronic Disease; D003352:Corynebacterium / Q000302:isolation & purification; D005122:Exudates and Transudates / Q000382:microbiology; D005260:Female; D005336:Fiber Optic Technology; D005673:Fusobacterium / Q000302:isolation & purification; D006801:Humans; D008168:Lung / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D009343:Neisseria / Q000302:isolation & purification; D055100:Optical Fibers; D012463:Saliva / Q000382:microbiology; D013291:Streptococcus / Q000302:isolation & purification; D013396:Suction; D014132:Trachea / Q000382:microbiology*; D014678:Veillonella / Q000302:isolation & purification