title: Prediction of tracheobronchial colonization in current cigarette smokers with chronic obstructive bronchitis.
abstract: To help in clarifying the conflicting data on the role of tracheobronchial microflora in chronic bronchitis, the tracheobronchial microflora of a homogeneous group of clinically stable patients with chronic obstructive bronchitis was characterized by transtracheal aspiration. Their mean percentage ratio of forced expiratory volume in 1 sec to the forced vital capacity was 45%. The results were that (1) a bacterial tracheobronchial microflora was present in only 50% of the patients, (2) viridans streptococci were the bacteria most frequently isolated, and (3) the presence or absence of a tracheobronchial microflora was significantly associated with the amount of present cigarette smoking. The fact that patients who smoke less than one pack per day were most likely to have a sterile tracheobronchial tree (P=0.015) implied that there was a critical amount of cigarette smoke that impaired the clearance and/or detoxification of bacteria from the tracheobronchial tree and that it must have been persistently present.
mesh_terms: D000328:Adult; D000368:Aged; D001991:Bronchitis / Q000382:microbiology*; D002908:Chronic Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D012907:Smoking; D013290:Streptococcal Infections / Q000382:microbiology*; D013291:Streptococcus / Q000302:isolation & purification; D014132:Trachea / Q000382:microbiology*; D014797:Vital Capacity