Submitted to: American College of Veterinary Pathologists Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/21/1997
Publication Date: N/A
Technical Abstract: Shiga-like toxin producing strains of E. coli O157:H7 are often isolated from stools of patients with Hemorrhagic Colitis (HC). Neutrophilic infiltration is a prominent feature of the enteric lesions in HC; however, the degree of neutrophilic infiltration is difficult to assess by routine histopathology. In a neonatal bovine model of HC (Dean-Nystrom, et al, Infect Immun 65 (5):1842-1848, 1997) induced by E. coli O157:H7, calves develop acute mucosal damage which contains infiltrates of neutrophils. In order to semi-quantitate the degree of neutrophilic infiltration, neutrophils were stained by immunohistochemistry and sections of intestine were captured electronically with an SGI O2 workstation with VISILOG software. Images were edited on a Micron Computer with Photoshop software. Edited images were measured with the VISILOG software on the workstation and numbers of neutrophils/um in localized sites of the mucosa were determined. These sites included: a) enterocyte layer covering intestinal villi and domes, b) lamina propria of villi and domes, and c) lamina propria between the lamina muscularis and intestinal crypts, d) remaining intestinal wall. We have found that the greatest degree of neutrophil infiltration is present in the dome epithelium and lamina propria and in focal aggregates of neutrophils in the lamina propria of villi. These findings establish a quantitative baseline for neutrophilic infiltration into the enteric mucosa.