Comparison of normal tracheal tissue and tracheitis with inflammatory cell infiltration in M. gallisepticum -infected birds. Figure 2A: Trachea of a partridge from the control group. Normal mucosa lined with a pseudo-stratified columnar epithelium with kinocilia (1) and a fibrocartilaginous layer (2) are presented. No signs of inflammation were observed in any of the tracheal layers. Epithelial detachment is artificial due to sample processing. H&E stain.
Figure 2B: Trachea of a partridge infected with M. gallisepticum. The inflammatory exudate, composed mostly of heterophils, is adhered to the epithelium (1). The epithelium is moderately hyperplastic with loss of the kinocilia and lamina propria is moderately infiltrated by lymphocytes and plasma cells (2). The fibrocartilaginous layer (3) is composed of the dense connective tissue mildly infiltrated by lymphocytes and plasma cells, and the perichondrium and hyaline cartilage. H&E stain.