Shigella: Genus, Gram-Negative Bacteria, Bacteria, Shigellosis, Dysentery, TSI Slant, Infectious Diarrhea, Endospore, Shiga-Like Toxin, Shiga Toxin, Enterotoxin

High Quality Content by WIKIPEDIA articles! Shigella is a genus of Gram-negative, non-spore forming rod-shaped bacteria closely related to Escherichia coli and Salmonella. The causative agent of human shigellosis, Shigella cause disease in primates, but not in other mammals. It is only naturally found in humans and apes. During infection, it typically causes dysentery. Group A?C are physiologically similar; S. sonnei (group D) can be differentiated on the basis of biochemical metabolism assays. Three Shigella groups are the major disease-causing species: S. flexneri is the most frequently isolated species worldwide and accounts for 60% of cases in the developing world; S. sonnei causes 77% of cases in the developed world, compared to only 15% of cases in the developing world; and S. dysenteriae is usually the cause of epidemics of dysentery, particularly in confined populations such as refugee camps.