Bacterial Virulence Flashcards
Give a definition for virulence
The capacity of a microbe to cause damage to the host
What is a virulence factor?
A molecule used by the pathogen to aid its attack
Give some examples of virulence factors and how they aid the pathogen
Adhesin - enables binding of organism to host
Impedin - enable organism to avoid host defence mechanisms
Aggresin - damages host directly
Give examples of specific virulence factors for staph aureus
Fibrinogen binding protein
PVL
TSST-1
What are the two main organisms found on the skin?
Staph aureus
Staph epidermidis
Name some staph aureus skin conditions
Rash
Abscess
Impetigo
Scaled skin syndrome
Explain the role of adhesins in staph aureus infecting wounds
Staph aureus contains a specific adhesin (fibrinogen-binding) which can bind to the blood clot
How can TSST-1 cause scaled skin syndrome?
As it can cause a breakdown in the specific crossbridges of the epidermidis
Strep pyogenes is an example of which group streptococci?
Group A (causes beta haemolysis)
What skin infections can strep pyogenes cause?
Impetigo
Necrotising fascitiitis
Toxic shock like syndrome
M protein is an adhesin found where?
Oropharynx and nasopharynx
Why is M protein a problem for the skin?
It can stick to keratinocytes
If a bacteria is more capsulated, will it be more or less virulent?
More virulent
