What are the characteristics of Shigella dysenteriae?
Christopher Harper
Updated on April 02, 2026
Symptoms of shigellosis include abdominal pain, tenesmus, watery diarrhea, and/or dysentery (multiple scanty, bloody, mucoid stools). Other signs may include abdominal tenderness, fever, vomiting, dehydration, and convulsions.
What is the morphology of Shigella dysenteriae?
Shigella species are small Gram negative rods, 0.3 – 1µm in diameter and 1 – 6µm in length, appearing singly, in pairs and in chains. Shigella species are facultative anaerobes and are non-spore formers. Unlike Salmonella, Shigella species do not possess flagella and hence are non-motile.
How do you identify Shigella?
Infection is diagnosed when a laboratory identifies Shigella in the stool (poop) of an ill person. The test could be a culture that isolates the bacteria or a rapid diagnostic test that detects genetic material of the bacteria.
How does Shigella dysenteriae reproduce?
Shigella cells will pass DNA through a sex pilus. The sex pilus joins the two cells together and pulls the cells very close together for the DNA transfer in the cytoplasm. DNA polymerase is synthesized then the DNA will move through the sex pilus from the donor cell to the receiver cell.
What causes shigella dysenteriae?
It’s caused by a group of bacteria called Shigella. The Shigella bacterium is spread through contaminated water and food or through contact with contaminated feces. The bacteria release toxins that irritate the intestines, causing the primary symptom of diarrhea.
How does Shigella dysenteriae spread?
How is Shigella spread? Shigella is found in the intestinal tract of infected people, and is spread by eating or drinking food or water contaminated with the bacteria. It can also be spread by direct contact with feces (even with microscopic amounts) from an infected person.
How is Shigella dysenteriae diagnosed?
To confirm the diagnosis of shigellosis, doctors take a sample of stool and send it to a laboratory to grow (culture) and identify the bacteria. Bacteria are also tested to see which antibiotics are effective (a process called susceptibility testing.
What are the biochemical properties of Shigella?
Biochemical Test and Identification of Shigella flexneri
| Basic Characteristics | Properties (Shigella flexneri) |
|---|---|
| Motility | Non-Motile |
| MR (Methyl Red) | Positive (+ve) |
| Nitrate Reduction | Positive (+ve) |
| Oxidase | Negative (-ve) |
What phylum is Shigella dysenteriae in?
Proteobacteria
Shigella dysenteriae/Phylum
What causes Shigella dysenteriae?
What diseases are caused by Shigella?
Hemolytic uremic syndrome. This rare complication of shigella, more commonly caused by bacteria called E. coli, can lead to a low red blood cell count (hemolytic anemia), low platelet count (thrombocytopenia) and acute kidney failure. Toxic megacolon.
What is the implicated illness of Shigella?
Shigellosis is an infectious disease caused by Shigella. The Shigella germ is a family of bacteria that can cause diarrhea in humans. People with shigellosis shed the bacteria in their feces. The bacteria can spread from an infected person to contaminate water or food, or directly to another person.
How do you treat Shigella?
People with shigellosis should not use anti-diarrheal medication. These medications may make symptoms worse 3.
Is Shigella food poisoning serious?
Shigella food poisoning is usually mild, but it can be serious and sometimes fatal. Any person suffering severe symptoms of the illness, such as visible blood in the stool, seizure, or confusion, should receive medical attention. Young children, elderly people, and people with weakened immune systems are most vulnerable.
