LOS

Definition

LOS (Lipooligosaccharide) is a component of the outer membrane of certain Gram-negative bacteria. It plays a key role in the pathogenesis and immune evasion in bacterial infections of the nervous system.

5 Must Know Facts For Your Next Test

1. LOS is structurally similar to LPS (lipopolysaccharide) but lacks the O-antigen polysaccharide chain.
2. It can trigger strong inflammatory responses, leading to symptoms like fever and septic shock.
3. Neisseria meningitidis, a major cause of bacterial meningitis, utilizes LOS as part of its virulence factors.
4. Antibiotic resistance can be influenced by modifications in LOS structure, affecting treatment efficacy.
5. Detection and analysis of LOS can be crucial for diagnosing specific bacterial infections.

Review Questions

• What structural feature distinguishes LOS from LPS?
• How does LOS contribute to the pathogenicity of Neisseria meningitidis?
• Why is understanding LOS important for developing treatments against bacterial infections?

Related terms

Gram-negative bacteria: Bacteria that have a thin peptidoglycan layer and an outer membrane containing lipopolysaccharides.

LPS (Lipopolysaccharide): A large molecule consisting of a lipid and a polysaccharide, found in the outer membrane of Gram-negative bacteria.

Meningitis: An infection causing inflammation of the membranes covering the brain and spinal cord, which can be caused by various pathogens including bacteria.