🦠microbiology review

Lipooligosaccharide

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

Definition

Lipooligosaccharide (LOS) is a molecule found in the outer membrane of certain Gram-negative bacteria. It plays a crucial role in bacterial virulence and immune system evasion.

5 Must Know Facts For Your Next Test

  1. Lipooligosaccharide is structurally similar to lipopolysaccharide but lacks the O-antigen component.
  2. LOS is found in pathogens such as Neisseria gonorrhoeae, which causes gonorrhea, a common urogenital infection.
  3. The presence of LOS can trigger strong immune responses, including inflammation and cytokine release.
  4. LOS helps bacteria adhere to host cells, facilitating colonization and infection of the reproductive system.
  5. Antibodies targeting LOS can be used in diagnostic tests and potential vaccine development for bacterial infections.
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