Shigella

• Not significant cause of infection in domestic animals
• Causes dysentery in humans and primates
• Enteroinvasive, invading the intestinal mucosa and causing necrosis
• Do not cause systemic disease - they do not invade beyond the lamina propria to the bloodstream
• A large plasmid permits survival in cells and is responsible for invasivenss
• Closely related to E. coli - some strains produce Shiga toxin which is related to vero cytotoxin of E. coli