Shiga toxin

Definition

Shiga toxin is a potent bacterial toxin produced by Shigella dysenteriae and some strains of Escherichia coli. It inhibits protein synthesis in host cells, leading to cell death and severe gastrointestinal symptoms.

5 Must Know Facts For Your Next Test

1. Shiga toxin is known for causing bloody diarrhea and hemolytic uremic syndrome (HUS).
2. It functions by cleaving a specific adenine residue from the 28S rRNA of the ribosome, halting protein synthesis.
3. Shiga toxin-producing E. coli (STEC) is often acquired through contaminated food or water.
4. Antibiotic treatment can worsen the condition by increasing the release of Shiga toxin.
5. The receptor for Shiga toxin on human cells is globotriaosylceramide (Gb3), which is abundant in kidney cells.

Review Questions

• What are the primary symptoms caused by Shiga toxin?
• How does Shiga toxin inhibit protein synthesis in host cells?
• Why can antibiotic treatment exacerbate conditions caused by Shiga toxin?

Related terms

Hemolytic Uremic Syndrome (HUS): A severe condition characterized by hemolysis, thrombocytopenia, and acute kidney injury.

Escherichia coli O157:H7: A strain of E. coli that produces Shiga toxin and causes severe foodborne illness.

Globotriaosylceramide (Gb3): A glycosphingolipid found on cell surfaces that serves as a receptor for Shiga toxin.