Enteric Diseases Department
Throughout history, diarrheal diseases have had a major impact on military operations, and led to a significant loss of man-days on the battlefield. Providing the best treatment, along with intense preventive medicine efforts, is important, but is not nearly sufficient to overcome this health threat.
Because of the great impact these diseases can have on troops, researchers at the Naval Medical Research Institute (NMRC) are actively pursuing vaccines for enterotoxigenic E. coli, and Campylobacter jejuni—two of the most common causes of diarrhea in deployed forces.
Blocking ETEC Infection
Enterotoxigenic E. coli (ETEC), is the most common cause of travelers' diarrhea in U.S. forces deployed to less developed countries, and the leading cause of bacterial diarrhea in children living in these less developed regions of the world.
ETEC cause disease by attaching to the intestinal lining through specialized projections called fimbriae. Once attached, ETEC multiply and produce toxins that stimulate an outpouring of intestinal fluids, which can cause diarrhea and consequent dehydration.
Researchers at NMRC are developing vaccines that would block attachment and toxin activity, interrupting the infection at its earliest stages, which should reduce the number and severity of ETEC diarrhea cases.
Unlocking Mysteries of Campylobacter
Campylobacter jejuni is the most common bacterial cause of diarrhea in the U.S. and likely the second most common cause of travelers' diarrhea worldwide. C. jejuni generally causes a more severe disease than ETEC. The infection can be difficult to treat because of widespread antibiotic resistance.
The program at NMRC is firmly focused on vaccine development, but a great deal of basic research investment has been made to elucidate exactly how the organism causes disease, and determine the nature of immune responses that protect people against repeat infections.
The Molecular Biology Branch of the Enteric Diseases Department at NMRC, headed by Patricia Guerry, Ph.D., has been a world leader in this field. They have identified many surface structures of the bacteria, found how it invades human cells and characterized many aspects of the immune response.