Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Dermatology Lectures > Bacterial Virulence > Flashcards

Bacterial Virulence Flashcards

You may prefer our related Brainscape-certified flashcards:
Dermatology Board Prep flashcards
1
Q

What is virulence?

A

Pathogen/microbe ability to infect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Presentations of Staph aureus?

A
  • Superficial lesions
  • Systemic
  • Toxinoses (toxic shock, scalded skin sydrome)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Various skin infections of Staph Aureus?

A 
Rash 
Folliculitis 
Abscess 
Carbuncle (multioccular abscesses)
Impetigo 
Scalded skin syndrome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How many broad species are involved in Staphylococci?

A

Two significant skin colonizing species distinguished as coag +ve/-ve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

S. aureus is coagulase?

A

Positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

S. Epidermis is coagulase?

A

Negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When does S. Epidermis tend to cause infection?

A

Usually only in immunocompromised patients as most people have this pathogen on their skin.
Associated with foreign objects like a catheter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

S. Epidermis coagulases plasma. True or False?

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What percentage of general population carry S. aureus the whole time?

A

20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Staph aureus is normally found on?

A

Nasal passages and perineum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is MRSA defined by?

A

Resistance to flucloxacillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is toxinoses?

A

Discrete disease with single protein component, a toxin or exotoxin. (NOT THE ENDOTOXIN)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

TSST-1? (toxic shock syndrome 1)

A 
Rapid progression 
Life threatening
High fever 
Vomiting 
Diarrhoea 
Sore throat 
Muscle pain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Staphylococcal Food poisoning?

A 
Intoxication (not living organism)
Self limiting
1-5 hours 
Vomiting 
Diarrhoea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Scalded skin syndrome?

A 
Often neonatal 
Face, axilla & groin 
Self-limiting 
Interferes with keratin/cystine cross-bridges causing continual shedding of skin
Toxin is a protease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Common cause of toxic shock syndrome?

A

TSST-1

17
Q

Mechanism of TSST-1?

A

Antigen is not processed by PMN binds directly to MHC11 complex.
Massive release of cytokines and inappropriate immune response

18
Q

Example of a superantigen?

A

TSST-1

19
Q

Diagnostic criteria for TSS?

A
  • Fever (39c)
  • Diffuse Macular Rash and desquamation (sun burn)
  • Hypotension (<90 mmHg)
  • 3 or more organ systems involved
20
Q

Virulence Factor?

A

Molecules produced by pathogen that add to their effectiveness and enable them to achieve many things

21
Q

What do virulence factors help pathogens achieve?

A
  • colonization of a niche in the host (this includes attachment to cells)
  • immunoevasion
  • evasion of the host’s immune response
  • immunosuppression
  • entry into and exit out of cells (if the pathogen is an intracellular one)
  • obtain nutrition from the host
22
Q

What proteins does Staph.Aureus require to adhere, survive and damage the host?

A
  • Fibrinogen Binding protein (adhesion)
  • Haemolysins - Cytolytic
  • Coagulase (clots plasma)
  • Leucocidin - inactivates leukocytes
  • TSST-1
23
Q

Virulence Factors that are linked to S. Aureus wound infections, necrotising pneumonia & toxic shock?

A

Protein A
Super antigens (TSST-1)
Gamma toxin, alpha toxin and PVL
Coagulase

24
Q

Necrotising pneumonia?

A
  • Preceding influenzae like symptoms
  • Rapid progression
  • Acute respiratory distress
  • Deterioration in lung function
  • Multi-organ failure
25
Q

Classification of virulence factors associated with S.pyogenes?

A

GAS( Group A streptococci)
Lancefield
Haemolysis (B, clear)

26
Q

Colonization of S. Pyogenes?

A

Large if pyrogenic

27
Q

Diseases caused by S. Pyrogenes?

A

Impetigo
Cellulitis
Erysipelas
Necrotising Fascilitis

28
Q

Describe impetigo?

A

On face
Enters skin via small defect
Children
DO NOT scratch

29
Q

Describe cellulitis?

A

Deeper skin infection

Invasion of dermis and SC fat

30
Q

Describe erysipelas?

A

Bright red rash
Localised to upper epidermis, lymphatic system
Fever rigours and nausea

31
Q

Describe necrotising fasciatis?

A

Type 2 caused by s.pyogenes S aureus
-Invasive group A strep strains penetrate mucous membrane and develop in lesion
Rapid destruction of connective tissue

Dermatology Lectures (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions