Figure 5

Pathological findings in brown bears with colibacillosis. A–D: Bear 41 (verotoxigenic Escherichia coli strain), E–F: Bear 48. A Vertebral column. Severe lesion located in L1-L2 with associated lordosis and lumbar scoliosis (inset, arrow). Osteolysis, loss of the intervertebral disc and spinal cord integrity, and presence of purulent material are also observed. B Cardia. Microscopic detail of the thrombus shown in inset (arrow). Loss of endothelial cells, hyaline degeneration of the vessel artery wall, and lines of Zahn are observed. Hematoxylin and eosin stain. Inset: One-centimeter thrombotic vascular lesion is observed (arrow). C Liver. A vascular thrombus is observed. Hematoxylin and eosin stain. Upper inset: Gram negative bacilli (asterisks) are present in the lumen of the thrombus. Gram stain. Lower inset: Numerous bacteria identified as E. coli using immunohistochemistry are present within hepatic sinusoids. ABC complex. D Adrenal gland. Presence of numerous Gram-negative bacilli inside blood vessels located in the adrenal cortex in the zona reticularis. Gram stain. Inset: Bacteria are identified as E. coli using immunohistochemistry. ABC complex. E Intestine. Presence of catarrhal enteritis with destruction of the intestinal microvilli of the intestinal mucosa. Inset: cub 48. F Numerous clumps of E. coli are identified in the intestinal lumen using immunohistochemistry. Avidin biotin complex.