A Pathogen Attacks While Keeping Up Defense.

GRAM-negative bacteria; EXCRETION; INTESTINAL diseases; SHIGELLA; ENTEROBACTERIACEAE; DIARRHEA

This article reports that many gram-negative bacteria interact with human, animal, or plant hosts by injecting effector proteins into the cytosol of host cells through the so-called type III secretion system. The symptoms of infectious diseases, such as bubonic plague, shigellosis, salmonellosis, typhoid fever, and infantile diarrhea, largely depend on the repertoire of bacterial proteins injected by the type III secretion system, and what they do once inside eukaryotic host cells. The enteric pathogen Shigella flexneri possesses a type III secretion system that enables invasion of the gut epithelial cells of mammalian hosts. Shigella species cause more than 1 million deaths per year from dysentery and diarrhea, and multidrug resistance of these bacteria is a rising problem.