Bacteriologic Flora of the Lower Respiratory Tract

THE complex nature of chronic bronchitis makes it difficult to define the relative importance of the many factors that might contribute to its pathogenesis and course.1 , 2 The progressive decline of the patient can generally be related to the number, length and severity of acute exacerbations that he suffers. The role of infection in the decline of the bronchitic patient is indicated by the morphologic findings in the bronchopulmonary tree,3 by the relative success of antibacterial treatment of the acute illness and by the occasional effectiveness of the prophylactic use of selected antibiotics.4 5 6 Much of the difficulty in evaluating the role . . .