🦠microbiology review

Listeria monocytogenes

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Listeria monocytogenes is a Gram-positive, rod-shaped bacterium responsible for the infection listeriosis. It is known for its ability to thrive in refrigerated conditions and can cause severe illness in immunocompromised individuals.

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5 Must Know Facts For Your Next Test

  1. Listeria monocytogenes can grow at temperatures as low as 0°C, making it a concern in refrigerated foods.
  2. It is a facultative anaerobe, meaning it can grow in both oxygen-rich and oxygen-poor environments.
  3. Listeriosis primarily affects pregnant women, newborns, older adults, and those with weakened immune systems.
  4. The bacterium uses actin-based motility to move within host cells and spread to adjacent cells.
  5. Symptoms of listeriosis include fever, muscle aches, and sometimes gastrointestinal symptoms; severe cases can lead to meningitis or encephalitis.

Review Questions

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