Brainscape's Knowledge GenomeTM

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


See full index

Dermatology > Microbiology > Flashcards

Microbiology Flashcards

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

What is virulence?

A

The capacity of a microbe to cause damage to the host

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

What is the pathogenesis of bacteria entering a host cell?

A

1) Host contact, colonisation, adheres and invades
2) Evade host defences
3) Multiply/ complete its life cycle
4) Exit host- host is undamaged

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

Name some virulence factors

A

Adhesin, Invasin, Impedin, Aggresin, Modulin

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

In relation to virulence factors, what is an adhesion?

A
  • Enables binding of the organism to host tissue
  • Specific adhesions determines differences in strains
  • Contributes to the ability to colonise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In relation to virulence factors, what is an invasin?

A

-Enables the organism to invade a host cell/tissue

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

In relation to virulence factors, what is an impedin?

A

-Enables the organism to avoid host defence mechanisms

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

In relation to virulence factors, what is an aggressin?

A

-Causes damage to the host directly

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

In relation to virulence factors, what is a modulin?

A

-Induces damage to the host indirectly

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

What percentage of people carry Staph Aureus permanently and what percentage transiently?

A
  • 10-20% permenantly

- 40-60% transiently

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

How specific are nosocomial strains of Staph Aureus?

A

They can be traced back to individual patients e.g. MRSA

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

How does community acquired Staph Aureus tend to present?

A

-Abscess and rash

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

How does nosocomial acquired Staph Aureus tend to present?

A

-Immunocompromised, more difficult to treat, very flexible organisms

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

How does each organism cause a differing range of effects?

A

Not every strain carries every virulence factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Panton Valentine Leukocidin (PVL)?

A
  • A cytotoxin, Beta pore forming toxins from Staph Aureus

- It has a specific toxicity for leukocytes and attacks WBCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is toxic shock syndrome?

A

-One of the virulence factors of Staph Aureus, super antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is associated with Toxic Shock Syndrome?

A

Fever, hypotension, 3 organs involved

17
Q

What is Necrotising Pneumonia and what causes it?

A
  • Rapid progression, multi-organ failure

- Caused by PVL and alpha exotoxin from Staph Aureus

18
Q

What are the virulence factors specific to Staph Aureus?

A

-Adhesins, PVL, Superantigens (TSST-1)

19
Q

What is the major of adhesins in Staph Aureus?

A

90% are joints, fibrinogen binding protein

20
Q

What 3 skin infections are associated with Strep pyrogenes?

A

Impetigo, Cellulitis (Erysipelas), Necrotising fasculitis

21
Q

What is cellulitis?

A

Deeper skin infection in the dermis that is not associated with necrosis

22
Q

What is erysipelas?

A
  • Similar to cellulitis, infection of upper dermis and superficial lymphatics, usually caused by beta haemolytic group A strep
  • More superficial than cellulitis, more raised and demarcated
23
Q

What is Impetigo?

A
  • Highly contagious
  • Through contact with discharge on the face
  • Infection if below the surface
24
Q

What is Necrotising fasciitis?

A
  • “Flesh-eating disease”
  • Invasive Strep A strains penetrate mucus membrane and develop in lesions
  • Rapidly destroys connective tissue
25
Q

What is the Lancefield System?

A
  • Sereotyping of cell wall carbohydrate

- Major sereotypes are A-H and K-V

26
Q

What are the major M protein antigens in the Lancefield System?

A

M1+ M3= major sereotype

M3+ M18= severe invasive disease

27
Q

What are the differences in presentation of Toxic Shock Syndrome in Staph Aureus and Strep Pyrogenes?

A

Staph Aureus

  • Localised infection
  • No bacteremia
  • Menstral TSST-1
  • Non menstral SEB or SEC
  • Pyrogenic Toxin
  • Virulence factor

Strep Pyrogenes

  • Invasive disease
  • Spec A and Spec C (most common toxin)
  • Pyrogenic toxin
  • Virulence factor
28
Q

What antibiotic should be used in Staph Aureus infections?

A

Flucloxacillin

29
Q

Give 3 examples of toxins produced by Staph Aureus

A

Enterotoxin (food poisoning)
SSSST (staph scalded skin syndrome toxin)
PVL (panton Valentine Leukocidin)

30
Q

What is the organism which causes urinary tract infections in women of child-bearing age?

A

Staph saprophyticus

31
Q

Name a toxin produced by Beta Haemolytic Streptococci

A

Haemolysin

32
Q

What does group A and group B Beta haemolytic Streptococci cause?

A

Group A: throat, severe skin infections

Group B: meningitis in neonates

33
Q

What is the difference between resident bacterial flora and transient bacteria?

A

Resident: organism can be deep in hair follicles and hard to wash away

Transient: can get rid of with hand washing

34
Q

Give examples of bacterial skin infections that Staph Aureus can cause

A 
Boils and Carbuncles
Cellulitis
Infected eczema
Impetigo
Wound infection
Staphylococcal scalded skin syndrome
35
Q

What is the difference between a boil and a carbuncle?

A

Boil: skin is traumatically pulled out of follicle

Carbuncle: Deeper infection, ofter at the nape of the neck at the hair line. Requires oral flucloxacillin

36
Q

What is impetigo?

A
  • Contagious superficial infection caused by Staph Aureus
  • Lesions well defined and start around nose and face with honey coloured crusts on erthyematous base
  • Usually seen in children aged 2-5 years
37
Q

What is cellulitis?

A
  • Acute infection of skin and soft tissue
  • Caused by staph aureus and group A Beta haemolytic strep
  • Deeper and less well defined than Erysipelas
38
Q

What is Staphylococcal Scalded Skin?

A
  • Widespread formation of fluid filled blisters that are thin walled and easily ruptured
  • Most common in neonates
  • Agressive antibiotics and rehydration due to loss of fluid due to weeping of skin
  • Mucous membranes are spared
39
Q

What is Erysipelas?

A
  • Sharply defined superficial infection caused by Strep pyrogenes
  • Often affects the face, unilateral, with increased WBC and fever
  • Systemic Penicillin

Dermatology (14 decks)

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