EXPERIMENTAL MOUSE PNEUMONIA FOLLOWING LUNG INJURY WITH ONE PERCENT FORMALDEHYDE
Klebsiella pneumoniae or Serratia marcescens was inhaled in the mouse with intact or injured lung. Injury of the respiratory tract was realized by inhalation of 1％ formaldehyde. By light and scanning electron microscopy, loss of the cilia and swelling of the epithelial cells were observed in the tracheo-bronchial tree, along with thickening of the alveolar septum accompanied by small round cell infiltration. By means of the inhalation of Klebsiella, typical pneumonia was provoked in the injured mouse, rarely in the intact mouse. Following the inhalation of Serratia, experimental pneumonia was not established in the intact mouse, nor in the injured mouse.