Shigella

Shigella boydii

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Shigella dysenteriae

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Shigella flexneri

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Shigella sonnei

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Shigella are Gram-negative, nonmotile, nonsporeforming rod-shaped bacteria. They are pathogens of humans and other primates, causing shigellosis. Depending on age and condition of the host, as few as 10 bacterial cells can be enough to cause an infection. The disease is caused when virulent Shigella organisms attach to, and penetrate, epithelial cells of the intestinal mucosa. After invasion, they multiply intracellularly, and spread to contiguous epitheleal cells resulting in tissue destruction. Some strains produce enterotoxin and Shiga toxin (very much like the verotoxin of ).

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Gram-negative: Bacteria that are Gram-negative are not stained dark blue or violet by Gram staining, in contrast to Gram-positive bacteria. On most Gram-stain preparations, Gram-negative organisms will appear red or pink because they are counterstained....

Pathogen: A pathogen literally "birth of pain" from the Greek παθογένεια) is a biological agent that can cause disease to its host. A synonym of pathogen is "infectious agent"....

Shigellosis: Shigellosis, also known as bacillary dysentery in its most severe manifestation, is a foodborne illness caused by infection by bacteria of the genus Shigella. It accounts for less than 10% of the reported outbreaks of foodborne illness in the USA. Shigellosis rarely occurs in animals; it is princip...