Virulence factor | Role in pathogenesis | Ref |
Capsule | Prevents opsonophagocytosis | |
Hyaluronidase | Helps in the spread of infection through host tissues | |
Pilus | Mediates attachment of pneumococci to host cells | |
IgA protease | Breaks down human IgA1 | |
Neuraminidase | Exposes pathogen binding sites in host by cleaving sialic acid | |
PspA | Causes inhibition of complement activation; binds to lactoferrin | |
PspC | Hinders formation of C3b; binds to slgA and factor H | |
Autolysin A | Causes autolysis of pneumococci and release of pneumolysin | |
Pneumolysin | Acts as a cytolytic toxin and activates complement |