This site is intended for healthcare professionals

Sign in
Go to /sign-in page

You can view 5 more pages without signing in

Virulence and pathogenicity

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

The following extracellular toxins have been characterised:

  • streptokinase - lyses fibrin by catalysing conversion of plasminogen to plasmin. Also produced by some members of Lancefield Groups B,C,G and F.
  • hyaluronidase - may contribute to invasiveness
  • hyaluronic capsule - protects organism from host defences
  • NADase - nicotinamide adenine dinucleotidase - kills leucocytes
  • haemolysins - two key types, both toxic to leucocytes:
    • streptolysin S - responsible for beta haemolysis
    • streptolysin O - used in serodiagnosis
    • also, deoxyribonuclease
  • erythrogenic toxin - produced by strains infected with lysogenic phage; responsible for rash of scarlet fever. Non-immunity demonstrated by Dick test - injection intradermally produces localised erythema.
  • surface protein antigens - M antigen associated with virulence (epithelial adhesion and anti-phagocytic / complement activity; T and R not virulent - used in epidemiologic studies
  • other enzymes - include leucocidin, protease and amylase

Create an account to add page annotations

Create a free account

Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.

The content herein is provided for informational purposes and does not replace the need to apply professional clinical judgement when diagnosing or treating any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions.

Connect

Copyright 2024 Oxbridge Solutions Limited, a subsidiary of OmniaMed Communications Limited. All rights reserved. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions receives funding from advertising but maintains editorial independence.