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Flashcards in Virulence Deck (48)
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1

What 3 things should be considered in infectious diseases

Symptoms
Organism
Virulence Factors

2

What part of the skin prevents colonisation of micro-organisms

The waterproof epithelial surface is constantly shedding and waterproof

3

Bacteria require iron. How do they obtain this

They rely on haemolysis of RBCs

4

What is virulence

The capacity of a microbe to cause damage to the host.
i.e what amount of organisms are required to cause death to the host
A measure of how well they can cause disease

5

What is adhesin

Enables binding of the organism to host tissue

6

What is invasin

Enable the organism to invade a host cell/ tissue

7

What is Impedin

Enables the organism to avoid host defence mechanisms

8

What is aggressin

Causes damage to the host directly
It affects the hosts ability to respond to diseas

9

What is Modulin

Induces damage to the host indirectly
Turn the immune system in in itself

10

What can lead to the amputation of limbs

Aggressins

11

What are the 3 main skin microbiota

Staplococci spp
Staphlococcus aureus
Diptheroids

12

If staph aureus is acquired in the community, what does it tend to lead to?

Serious skin infection

13

Staph epidermidiis is carried on most people but it only affects some. Who are these people

Immunocompromised

14

Who is at risk of developing MRSA

elderly and immunocrompromised
ICU
Burns patients
surgical patients
IV lines
Dialysis patients

15

Define nosocomial

Hospital borne infection

16

Why is staph aureus classed as a successful organism

Because it is so adaptive and therefore can survive in different environments

17

What makes a an organism successful

The number of virulence factors that lead to the organism to being adaptive

18

Name some virulence factors

Capsule
Fibrinogen Binding protein
Coagulase
Leukocidin
TSST-1 (toxin)
Enterotoxin
Adhesin
Clots plasma
Digests fibrin
Kills Leukocytes
Vomiting and Diarrhoea
Shock, rash, desquamation

19

Why might staph aureus cause a different reaction in different areas of the body?

Its ability to produce different virulence factors causing differences in disease

20

Give 2 examples of Adhesins

Fibrinogen-Binding (ClfA and ClfB)
Collagen-Binding (CNA)

21

How does protein A work to cause disease?

It stops the immune system from working as it binds the wrong immunoglobulin

22

What does PVL stand for

Panton Valentine Leukocidin

23

What is PVL and alpha toxin linked with

CA-MRSA

24

Describe the progression of necrotising pneumonia

Rapid progression

25

Why does giving a patient with necrotising pneumonia not help

The tissue is already being destroyed and the damage has already been made and is therefore too late to reverse this.

26

What superantigen is associated with Toxic shock

TSST-1

27

What does TSST-1 do

Cause a massive release of cytokines and an inappropriate immune response

28

Where does the super antigen become stabalised

Outside the cell and not in the cleft

29

What 4 things must a patient have for them to be diagnosed with a superantigen

Fever (39)
Diffuse macular rash and desquamation
Hypotension (

30

Describe the appearance of Streptococcus pyogenes

Gram +ve cocci
Chains
Catalase negative
Haemolysis