Escherichia coli O157:H7

Definition

Escherichia coli O157:H7 is a pathogenic strain of the bacterium E. coli that can cause severe foodborne illness. It is characterized by its ability to produce Shiga toxin, leading to serious complications such as hemolytic uremic syndrome.

5 Must Know Facts For Your Next Test

1. E. coli O157:H7 is a Gram-negative, rod-shaped bacterium.
2. It produces Shiga toxin, which can damage the intestinal lining and cause bloody diarrhea.
3. This strain of E. coli can survive in acidic environments, making it resilient in the stomach.
4. It's often transmitted through contaminated food or water, particularly undercooked beef and unpasteurized milk.
5. Infection with E. coli O157:H7 can lead to hemolytic uremic syndrome (HUS), a serious condition that affects the kidneys.

Review Questions

• What toxin does Escherichia coli O157:H7 produce?
• How is E. coli O157:H7 typically transmitted to humans?
• What serious complication can result from an infection with E. coli O157:H7?

Related terms

Gram-negative bacteria: Bacteria that do not retain the crystal violet stain used in the Gram staining method.

Shiga toxin:

A potent toxin produced by certain strains of bacteria, including E. coli O157:H7, which inhibits protein synthesis in host cells.

Hemolytic uremic syndrome (HUS): A condition characterized by the destruction of red blood cells, low platelet count, and kidney failure; often associated with infection by Shiga toxin-producing bacteria.