Infectious Disease 2

Question 1

What is a Virulence Factor ?

Answer 1

Virulence Factor :

Component of a pathogen that contributes to its ability to cause disease

Question 2

What are examples of Virulence Factors ?

Answer 2

• Adhesin - Enables binding of the organism to host tissue, colonisation
• Invasin - Enables organism to invade a host cell/tissue
• Impedin - Enables the organism to avoid host defense mechanisms
• Aggressin - Causes damage to the host directly
• Modulin - Induces damage to the host indirectly (via immune system)

Question 3

In Bacterial Adhesion Surface molecules can have multiple roles…

what are these?

(6)

Answer 3

• Surface molecules can have multiple roles;
• Attachment/colonisation
• Rafting/co-aggregation
• Promote clotting
• Signal transduction
• Internalisation

Question 4

How can infection pathogens spread?

Answer 4

• Can be superficial or systemic (metastasis)
• Can be extra or intra cellular
• i.e. can invade tissue e.g. pass the lining of the gut or enter a specific cell type

• Can gain access via general contact or injection

• e.g. Lyme’s disease, malaria

Question 5

Where can pathogens go when the Penetrate of Epithelium

Answer 5

• blood vessel endothelium
• lymphatic system
• Enter Phagocytic Cells

Question 6

Pathogens can gain access to endodontic area of tooth through what process.. anearobi respiration or fermentaion .. which one is it?

What is the bacteria that will undergo this process in the teeth?

Answer 6

Fermentation

Oral Streptococci

Question 7

What can fermentation of Oral Streptococci cause when they invade teeth

Answer 7

Metabolic product, lactic acid, destructive

Question 8

How can Oral Streptococci in the mouth lead to Infective Endocarditis?

Answer 8

1. Pathogen gains temporary access to the bloodstream
2. Pathogens rapidly adhere via platelet fibrin deposition
3. Proliferation of microbes formation of vegetation
4. Heart function impaired

Question 9

What happens in endotoxin shock

Answer 9

Lipopolysaccharides can stimulate macrophages which Release Inflammatory Cytokines.

Question 10

What is Sepsis?

Answer 10

Sepsis The host response to severe infection.

• Small blood vessels become “leaky” and lose fluid into the tissues

which cause blood to become thicker which causes the heart to have to work harder, increasin HR

-less oxygen in the blood supply to go to essential organs causing them to shut down to maintain blood supply to brain