🦠microbiology review

Hemolysins

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

Definition

Hemolysins are toxins produced by certain bacteria that cause the lysis of red blood cells. They disrupt the cell membrane, leading to the release of hemoglobin.

5 Must Know Facts For Your Next Test

  1. Hemolysins play a crucial role in bacterial pathogenesis by allowing bacteria to access iron from hemoglobin.
  2. Staphylococcus aureus and Streptococcus pyogenes are common bacteria that produce hemolysins.
  3. Hemolysins can be detected using blood agar plates, where they create clear zones of hemolysis around bacterial colonies.
  4. Different types of hemolysins (alpha, beta, gamma) vary in their mechanism and extent of red blood cell destruction.
  5. The presence of hemolysins is often associated with more severe infections and increased virulence.

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