FIG 5.

H&E staining of lung tissue sections from 6- to 9-month-old baboons infected with B. pertussis. Six- to 9-month-old baboons were challenged with B. pertussis. Lung tissue samples were collected on days 2, 7, and 28 postchallenge, and H&E-stained slides were prepared as described in Materials and Methods. Representative images are presented. (A) Sample collected from an uninfected baboon. Note that the alveoli (*) are empty and there are few inflammatory cells in the interalveolar septum (yellow arrow). (B) Sample collected from a baboon at day 2 postchallenge revealing marked vascular leakage consisting primarily of intra-alveolar edema (which stains pink; black arrow). (C) Sample collected from a baboon at day 7 postchallenge revealing moderate vascular leakage and marked lung consolidation. Note the almost complete loss of alveolar space and the influx of inflammatory cells and edema. (D) Sample collected from a baboon at day 28 postchallenge revealing marked lung consolidation and BALT hyperplasia (white arrow) with the conducting airways obstructed by macrophages and sloughed mucosal epithelial cells (black arrow). Magnifications, ×200.