Thesis - Open Access
Master of Science (MS)
Biology and Microbiology
Colibacillosis (CB) is a collective term which has been used to describe a group of diseases caused by the gram negative bacillus Escherichia coli. The disease affects neonatal calves, lambs, and piglets, weaned pigs, older pigs and poultry. Certain E. coli also cause a diarrheal disease in human adults and infants. Escherichia coli have been divided into two groups, pathogenic and non-pathogenic. The pathogenic strains may be further divided according to the manifestations of the infection. The differences are in tissue localization of the E. coli and in the biological activity of the E. coli enterotoxins responsible for each syndrome. Therefore, The enteric diseases caused by E. coli are described as enterotoxic, enterotoxemic and local invasive CB. The characteristic features of enterotoxic CB are proliferation of E. coli in the lumen of the small intestine with no invasion of the epithelial cells and production of an enterotoxin which causes the small intestine to secrete abnormally large volumes of fluid. Enterotoxemic CB manifests itself as localization of E. coli in the small intestine where the bacteria produce a toxin which is absorbed arid acts elsewhere. Edema disease in swine and enterictoxemic CB in calves are two well-known examples of this type. Invasion and destruction of intestinal epithelium by E. coli are the characteristics of local-invasiye CB. The host develops ulcerative enteritis, dysentery and fever. Local invasive colibacillosis is similar to shigellosis. The work reported herein will be concerned only with the enterotoxic form of CB and the enterotoxins produced by E. coli. The disease is characterized by a profuse watery diarrhea, severe dehydration, electrolyte imbalance, apathy, hypothermia and death if therapeutic measures are not taken.
Library of Congress Subject Headings
Escherichia coli infections
Cattle -- Diseases
South Dakota State University Theses
Number of Pages
South Dakota State University
Kienholz, Judy Carol, "Investigations of Heat-labile and Heat-stable Enterotoxins Produced by Escherichia Coli Isolated from Naturally Occurring Bovine Colibacillosis" (1973). Electronic Theses and Dissertations. 3895.