Authors : Christopher M. Jay , Shoba Bhaskaran , G. Gale Wagner and Suryakant D. Waghela
Abstract: Enterotoxigenic Escherichia coli (ETEC) attach to host enterocytes through the use of colonizing factor antigens, also known as pili. Different strains of ETEC can have 1 or more different types of pili, but the predominant colonizing factor antigen found on E. coli isolated from cattle contain the F5 antigen known as K99. The K99 pilus recognizes a GM3 glycoprotein that is found on newborn bovine enterocytes and equine erythrocytes. After the bacteria has attached to the enterocyte, enterotoxins are released that lead to colibacillosis. Blocking the interaction between the pili and host receptor will inhibit colibacillosis. By understanding how K99 interacts with the GM3 receptor, the treatments to reduce colibacillosis in neonatal cattle can be improved. K99 pili was grown and harvested from E. coli strain B41 (O101:K-:K99). The isolated pili were treated under different denaturing conditions and the protein activity was analyzed by hemagglutination assay. We confirmed that the entire K99 subunit must be maintained in its native conformation to retain hemagglutination activity. Any loss of 3D conformation or truncation of the K99 subunit destroys agglutination activity.
Christopher M. Jay , Shoba Bhaskaran , G. Gale Wagner and Suryakant D. Waghela , 2005. The Loss of Hemagglutination Activity of the Enterotoxigenic Escherichia coli K99 Pili Following Treatment with Enzymes or Chemicals That Destroy the Conformational Structure . Journal of Animal and Veterinary Advances, 4: 83-89.