Figure 9.

Histopathology and immunohistochemistry of the fetal lungs in saline controls (A,E,I), a GBS case delivered at 24 h (B,F,J) and 48 h (C,G,K) and with BSCI treatment (D,H,L). Staining for hematoxylin and eosin staining (A–D), MPO (E–H), and CD68 (I–L) was performed. In the fetal control lungs, there were few macrophages and rare neutrophils (A). GBS inoculation alone was associated with recruitment of neutrophils and macrophages, congestion and alveolar hemorrhage. Pre-treatment with the BSCI and GBS inoculation was associated with similar features, but greater neutrophil recruitment and more severe histopathologic features of pneumonia (D, 72 h after GBS inoculation). Immunostaining for MPO and CD68 demonstrated a subjective increase in MPO+ cells (H) in the BSCI treated vs. GBS alone group (F,G,J,K) at 72 h post-inoculation.