Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Biology and Microbiology


Enterotoxigenic Escherichia coli that expresses the K88 fimbrial adhesin is a common cause of diarrhea in nursing and weanling pigs. They account for more than 1 5% deaths in pigs due to gastrointestinal diseases in the State of South Dakota. In this study we measured cAMP levels in isolated non-adhesive or adhesive pig enterocytes following interaction with six K88 £. coli strains expressing K88 antigenic variants K88ab, K88ac, and K88ad and two E. coli strains which do not express K88 adhesin (K 12 and G 58-1). We also tested the effect of cholera toxin and purified K88 + adhesion on cAMP levels in pig enterocytes. Binding of K88 + E. coli strains significantly increased cAMP levels in adhesive pig enterocytes and had no effect on the non-adhesive pig enterocytes. Cholera toxin and purified K88 adhesin did not have significant effect on cAMP levels in pig enterocytes. These results suggest that the increased levels of cAMP in enterocytes was the result of bacterial binding and not due to toxin interaction. Further, results from purified K88 adhesin study suggest that binding of the entire bacteria in necessary to bring about this change.

Library of Congress Subject Headings

Escherichia coli infections in swine Swine -- Diseases



Number of Pages



South Dakota State University