<i>Shigella</i> Pathogenesis
Pamela Schnupf, Philippe Sansonetti
Abstract
Shigella spp. are diarrheal pathogens closely related to Escherichia coli. They are named after Kiyoshi Shiga, who in 1898 identified its most virulent member, Shigella dysenteriae, as the causative agent of bacillary dysentery, also known as shigellosis (1). Shigella spp. are Gram-negative, non-spore-forming, facultative anaerobic bacilli that in humans and other primates cause diarrheal disease by invading the colonic epithelium. Spreading of the infection is generally limited to the intestinal lining, where it leads to colonic inflammation, mucosal ulceration, and a loss in intestinal barrier function. Shigellae are transmitted through the fecal-oral route or through ingestion of contaminated food and water. In most cases, Shigella spp. cause a self-limiting disease that can be effectively treated by oral rehydration or antibiotics, although a steady increase in the number of shigellosis cases caused by antibiotic-resistant Shigella strains has become a growing concern (2, 3). Shigellosis can be fatal in the very young and in infected individuals who are immunocompromised or do not have access to adequate medical treatment.