How one bacterium causes diarrhea

Infection with enteropathogenic E. coli (EPEC) is a major cause of diarrhea in infants and has a high rate of mortality.

Developing new approaches to treat individuals infected with this bacterium requires increasing our understanding of the mechanisms by which it causes diarrhea. In a study appearing online on January 25 in advance of publication in the February print issue of the Journal of Clinical Investigation, Ravinder Gill and colleagues from the University of Illinois at Chicago, show that the exchange of Cl- and OH- by intestinal cells (something that if disturbed can lead to diarrhea) is inhibited by the bacterial proteins EspG and EspG2 in both human cells infected with EPEC in vitro and mice infected with EPEC. Further analysis revealed that EspG and EspG2 inhibit the exchange of Cl- and OH- by decreasing the amount of a protein known as DRA at the surface of intestinal cells. This study therefore identifies a potential mechanism by which infection with EPEC could cause diarrhea. - Journal of Clinical Investigation