Fig. 10
From: Lesions and pathogens found in pigs that died during the nursery period in five Danish farms
Gross and histological lesions in intestine and joints. A Necrotizing and proliferating ileitis in a pig caused by Lawsonia intracellularis. Similar lesions were present in the jejunum, caecum and colon. B Caecum from a pig with necrotizing, proliferative enterocolitis and typhlitis (Same pig as in Fig. 10A). Histologically, the proliferation of the crypt enterocytes and positive staining of Lawsonia intracellularis (stained brown) in the apical cytoplasm of the crypt enterocytes confirms the diagnosis, immunohistochemical detection of L. intracellularis. C Synovial villus with infiltration of macrophages. Escherichia coli (stained red) is present in the tissue and has been phagocytized by macrophages (arrows) indicating a genuine bacterial infection, immunohistochemical detection of E. coli. D Periarticular connective tissue from a joint with arthritis. Escherichia coli (stained red) is present in the vasculature (arrow). The absence of an inflammatory reaction near the bacteria is compatible with postmortem migration and proliferation of bacteria, immunohistochemical staining