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Shigella is a Gram-negative bacterium that belongs to the Enterobacteriaceae family.
There are 4 species of Shigella:
S. dysenteriae, S. flexneri; S. boydii; and S. sonnei, and each has its own serotypes.
Now, Shigella is a gram-negative, rod shaped bacterium, meaning it looks like a little red or pink stick on a gram stain.
And it’s a facultative anaerobe, so it can survive with or without oxygen in the environment.
It has no flagellum, making it nonmotile; and it doesn’t form spores.
It’s also a non-lactose fermenter, so it doesn’t ferment lactose; and it’s urease and oxidase-negative, meaning it doesn’t produce these enzymes.
On this medium, Shigella mostly forms white, non-lactose fermenting, non-hydrogen sulfide-producing colonies
There, it targets the epithelial layer of the mucosal lining where it infects colonic enterocytes and microfold cells, or M-cells.
MALTs are a type of mucosal immune tissue that extends into the submucosa, and contains plenty of immune cells like macrophages.
Shigella is a genus of bacteria known to cause a contagious form of gastroenteritis known as shigellosis. Shigellosis is characterized by an inflammation of the gastrointestinal tract, which causes destruction and inflammation of the epithelium, leading to dysentery with symptoms like severe abdominal and rectal cramping and pain, a fever, and watery diarrhea with mucous with or without blood or pus. Shigella is transmitted through the fecal-to-oral route, mainly through fingers, food, and flies. It's diagnosed with a fecal sample and treatment centers around fluid and electrolyte replenishment and antibiotics.
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