1985 Volume 59 Issue 3 Pages 245-254
Safe and simple methods for sampling sputum, which can be applied to general clinical fields, are desired for the survey of causative bacteria in pulmonary infection. In 171 patients with pulmonary disease, local bronchial sputum was sampled with a brush used for the diagnosis of pulmonary carcinoma. The cultures of the samples thus obtained (bronchial secretions and exudates, abbreviated to BS) and of simultaneous, expectorated sputum were compared, and the following results, with regard to the degree of contamination associated with this method, the conditions for determining the causative bacteria of the isolated potential pathogens, etc., were obtained.
1) Agreement of the component species of bacterial flora between BS and simultaneous expectorated sputum was found in 26.9% of the patients.
2) The colony counts of Neisseria isolated from BS were judged as ++ in 5.3% and as slight or less in 65.5%. With expectorated sputum, corresponding counts were assigned to ++ or +++ in 65.5%. A similar distribution of colony counts was obtained for α-Streptococci. Thus, it is presumed that this sampling method is associated with minimal contamination of BS by indigenous bacterial flora in the upper airway.
3) The colony counts and the prophlogisticity of the pathogens were compared between pulmonary parenchymal infection and airway infection. When the colony counts of bacteria isolated from expectorated sputum were rated as ++ or +++, 31.3% of the bacteria were causative in pulmonary parenchymal infection, and 100% in airway infection. When the colony counts of bacteria isolated from BS were ++ or +++, 100% were causative in both infections.
4) The frequency of causative bacteria isolated from purulent sputum was markedly higher than in other specimens.
On the basis of the above results, the position of this method in the survey of causative bacteria in pulmonary infection is also discussed herein.
