Naturally acquired attaching and effacing Escherichia coli in sheep

• Published in: Research in veterinary science Vol. 78; no. 2; pp. 109 - 115
• Main Authors: Wales, A.D., Pearson, G.R., Best, A., Cookson, A.L., La Ragione, R.M., Roe, J.M., Hayes, C.M., Woodward, M.J.
• Format: Journal Article
• Language: English
• Published: England Elsevier India Pvt Ltd 01.04.2005; Elsevier Limited
• Subjects: Animals; Animals, Newborn; Antibodies, Bacterial - analysis; Attaching; bacterial adhesion; Colon - microbiology; Colon - pathology; Colon - ultrastructure; disease detection; disease prevalence; E. coli; Effacing; Escherichia coli; Escherichia coli Infections - microbiology; Escherichia coli Infections - pathology; Escherichia coli Infections - veterinary; Escherichia coli O157 - growth & development; Escherichia coli O157:H7; Escherichia infections; Feces - microbiology; Female; histopathology; Ileum - microbiology; Ileum - pathology; Ileum - ultrastructure; Immunohistochemistry - veterinary; intestinal mucosa; Intestinal Mucosa - microbiology; Intestinal Mucosa - pathology; Intestinal Mucosa - ultrastructure; Latex Fixation Tests - veterinary; lesions (animal); Microscopy, Electron, Transmission - veterinary; Naturally acquired; Sheep; sheep diseases; Sheep Diseases - microbiology; Sheep Diseases - pathology; symptoms; Veterinary medicine; Attaching; Sheep; Naturally acquired; Effacing; E. coli
• ISSN: 0034-5288; 1532-2661
• DOI: 10.1016/j.rvsc.2004.07.002

In a series of experiments involving the inoculation of sheep with Escherichia coli O157:H7, and subsequent detailed histopathological examination of the intestinal mucosa, attaching–effacing (AE) lesions formed by elements of the natural flora were observed in 18% of animals. These incidental AE lesions typically were small and sparse, and were not associated with clinical disease. It was possible to identify further some of the lesional bacteria, revealing that E. coli O115 had formed lesions in one of the seven affected animals, and similarly E. coli O26 had formed some of the lesions in another. As AE strains, source flocks, housing and feed sources were diverse, a common source of lesion-forming bacteria appears to be unlikely. It is postulated that subclinical AE lesions are a mechanism of persistence of AE bacteria in sheep.