Fig. 2

Intrapleural S. pneumoniae induces pleural injury and lung dysfunction. S. pneumoniae was intrapleurally administered and incubated for 7 days. a Weights were collected over 7 days (n = 3–7 mice/group). b Gross images taken at 7 days after administration of saline or S. pneumoniae. These animals did not receive antibiotic treatment. S. pneumoniae infection promotes extensive pleural injury with deposition of a transitional intrapleural fibrinous neomatrix that is readily appreciated with coating and encasement of the lungs. Solid arrows indicate areas of neomatrix deposition within the thoracic cavity of S. pneumoniae infected mice. c Lung volumes and function (compliance) were significantly reduced by S. pneumoniae administration at 7 days (p < 0.05). d Lung tissue sections from saline-treated and S. pneumoniae infected mice (7 days post-infection) were trichrome stained, with collagen deposition indicated by the blue stain. By morphometry, S. pneumoniae infected mice demonstrated significantly more pleural thickening than saline controls (p < 0.001). Solid arrows indicate the pleural surface and the basement membrane of the thickened pleura. Areas of collagen deposition were observed within the thickened pleural rind of S. pneumoniae infected mice. Images were obtained at 20× and are representative of the finding of 30 fields/slide and 3–7 mice/group