Bacterial Virulence Flashcards Preview

Y2 Dermatology > Bacterial Virulence > Flashcards

Flashcards in Bacterial Virulence Deck (28)
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1
Q

where does staph aureus colonise?

A

the skin

mucous membranes

2
Q

where is s pyogenes normally found?

A

the pharynx

the skin

3
Q

what organisms cause toxic shock syndrome?

A

staph aureus

s pyogenes

4
Q

what are SSTIs?

A

skin and soft tissue infections

5
Q

name two toxinoses that can be caused by staph aureus

A

toxic shock syndrome

scalded skin syndrome

6
Q

name five skin presentations of staph aureus infection

A
rash 
folliculitis 
abscesses 
carbuncle 
impetigo
7
Q

what is folliculitis?

A

inflammation of hair follicles

8
Q

what is a carbuncle?

A

a multilocular abscess

9
Q

who is most commonly affected by scalded skin syndrome?

A

neonates

10
Q

how can a nasal strain of s aureus protect the body?

A

it can prevent a more aggressive strain from colonising and entering the body

11
Q

which staphylococci is coagulase positive?

A

staphylococcus aureus

12
Q

what is coagulase?

A

a virulence factor produced by s aureus that causes blood to coagulate

13
Q

what is staph epidermidis infection associated with?

A

immunocompromised patients

foreign medical devices such as catheters

14
Q

what are toxinoses?

A

diseases associated with a single protein component. a toxin or an exotoxin

15
Q

what is TSST-1?

A

toxic shock syndrome toxin 1

16
Q

describe the symptoms of toxic shock syndrome

A
rapid progression over 48 hours 
high fever 
vomiting 
diarrhoea 
sore throat 
muscle pain
17
Q

what is the diagnostic criteria for toxic shock syndrome?

A

fever
diffuse macular rash and desquamation
hypotension
three or more organ systems involved

18
Q

what are adhesins?

A

a type of virulence factor that facilitate adhesion to other cells/surfaces

19
Q

name three adhesins produced by s aureus

A

fibrinogen binding
fibronectin binding
collagen binding

20
Q

what is PVL?

A

panton valentine leukocidin

a group of proteins that forms a complex

21
Q

what does PVL do?

A

attacks white blood cells

22
Q

what is s aureus containing PVL associated with?

A

severe skin infections such as necrotising fasciitis

23
Q

what is necrotising pneumonia?

A

a severe complication of a mild infection, caused by destruction of immune cells

causes ARDS and multi organ failure

24
Q

what is necrotising pneumonia associated with?

A

PVL positive s aureus

25
Q

what is used to classify strep?

A

lancefield classification based off of surface antigens (the Lancefield carbohydrate)

26
Q

name some skin infections caused by s pyogenes

A

impetigo
cellulitis
necrotising fasciitis

27
Q

what lancefield group is s pyogenes in?

A

group A

28
Q

what is lancefield group A divided into?

A

further groups according to the M protein

M1, M3 = major serotype
M3, M18 = severe invasive disease