Immunizing calves with either of two forms of a vaccine newly developed by Agricultural Research Service (ARS) scientists might reduce the spread of sometimes deadly Escherichia coli O157:H7 bacteria. The microbe can flourish in the animals' digestive tracts, yet doesn't cause them to show clinical symptoms of illness.
In humans, however, E. coli can cause bouts of diarrhea and, sometimes, life-threatening hemolytic uremic syndrome.
Research microbiologists Vijay K. Sharma and Thomas A. Casey developed the novel vaccines in their laboratories at the agency's National Animal Disease Center in Ames, Iowa and are seeking a patent for it.
Preventing E. coli O157:H7 from proliferating inside cattle helps limit contamination of meat at the packinghouse, and reduces shedding of the microbe into the animals' manure. Manure-borne E. coli can be moved by rainfall into drinking water. What's more, it can end up in irrigation water, and can contaminate fruits, vegetables or other crops, increasing risk of an outbreak of foodborne illness.