A Potential E. Coli Vaccine to Prevent Travelers’ Diarrhea




Enterotoxic E. coli strains (ETEC) produce heat stable enterotoxin (STa).  ETEC strains are a common cause of diarrhea (travelers’ diarrhea in humans) and animals (scours).  Each year, approximately 20 million people will develop travelers’ diarrhea. Scours causes significant economic losses in cattle and swine through calf and piglet mortality, cost of treatment, and decreased growth rates. The severe diarrhea caused by ETEC strains is caused by STa, and STa is therefore an excellent vaccine target.  However, no component vaccines against STa have been developed because the toxin is nonimmunogenic and does not stimulate antibody production in infected subjects.  What is needed is a vaccine composition that allows the immune system to produce a strong reaction to STa.


Description of Technology

This invention is a STa-carrier protein conjugate that is highly immunogenic.  The STa-carrier conjugate retains its biological activity, and may be a substitute for magnesium sulfate/fiber in bowel clearance prior to bowel surgery and colonoscopy.  The neutralizing antibody titre observed in immunized rabbits was found to be superior to other STa conjugates reported in the literature.  STa immunizing antibodies can be harvested from immunized chicken eggs, and these antibodies may be useful in formulation of an ETEC therapeutic for treatment of traveler’s diarrhea and scours. 


Key Benefits

  • Highly immunogenic: MSU’s STa-carrier conjugate produces very high titres of neutralizing antibodies.
  • Stable: the STa-carrier conjugate can be dried down for storage.
  • Multiple market entry points:  ETEC affects both humans and animals, and properly formulated neutralizing antibodies may be used as a therapeutic.



  • Traveler’s diarrhea vaccine
  • Scours vaccine for cattle and swine
  • Bowel clearance prior to surgery or colonoscopy
  • Production of therapeutic antibodies
  • Antibody-containing feed supplement for prevention or treatment of scours in cattle and pigs


Patent Status

U.S. application 13/054,983 allowed.  EU and Canadian applications are pending




A. Mahdi Saeed


Tech ID




Patent Information:

For Information, Contact:

Thomas Herlache
Assistant Director
Michigan State University
A. Mahdi Saeed