surface components of pneumococci

Last reviewed 01/2018

The surface components of pneumococci include:

  • capsule:
    • capsular polysaccharide - protects pneumococci from phagocytosis by polymorphs
    • capsular polysaccharide is not necessary for inflammation

  • cell wall:
    • components of pneumococcal cell wall - stimulates the recruitment of leucocytes into the subarachnoid space and the lung, enhances the permeability of pulmonary alveolar epithelia and cerebral endothelia, induces cytokine production, stimulates platelet-activating factor (PAF) production, causes direct damage to neurons, and alters vascular-perfusion pressure and cerebral blood flow

  • surface proteins:
    • largely undefined - pneumolysin (an intracellular protein released during lysis) is cytotoxic to virtually every cell in the lung

Ref: Tuomanen EI et al (1995). Pathogenesis of pneumococcal infection. NEJM, 332, 1280-2.