Bacterial skin infections and warts Flashcards Preview

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Flashcards in Bacterial skin infections and warts Deck (50)
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1
Q

Necrotizing fasciitis causal organism

A

strep pyogenes

2
Q

initial diffuse redness, swelling and extreme tenderness

followed by crepitus, purple skin discoloration, bullae and loss of sensation to the area

A

Necrotizing fasciitis

3
Q

erysylpela causal organism

A

strep pyogenes

4
Q

causal organisms of cellulitis

A

S. areus
strep pyogenes
clostridium perfringens
pseudomonas

5
Q

virulence enzyme of clostridium perfringens and its mechanism

A

alpha toxin: lecitihinase

hydrolyzes cell membranes causing cell death

6
Q

causal organism of gas gangrene

A

clostridium perfringens

7
Q

causes of impetigo

A

Bullous: s. aureus
Nonbullous: strep pyogenes

8
Q

causal agent of furuncles and carbuncles

A

s. areus

9
Q

causes of folliculitis

A

s. aureus

pseudomonas

10
Q

treatments of clostridium infections

A

penicillin

clindamycin

11
Q

treatment for strep pyogenes

A

penicillin
macrolides
cephalosporins

12
Q

what causes scarlet fever in strep pyogenes infections

A

phag encoded toxin: pyogenic/ erythrogenic toxin

13
Q

virulence factors of Strep pyogenes that induce adherence

A

lipoteichoic acid

M protein

14
Q

role of M protein in strep pyogenes

A

adherence
molecular mimicry: avoiding apoptosis
antigen of Rheumatic fever and post strep glomerulonephritis

15
Q

which streptolysin is antigenic in strep pyogenes and what does it do

A

streptolysin O

Beta hemolytic- degrades cell membranes

16
Q

rol of streptokinase in strep pyogenes

A

converts plasmin into plasminogin

17
Q

role of hyaluronidase and where can it be found

A

breaks down connective tissues (hyaluronic acid)

S. areus and strep pyogenes

18
Q

virulence factor of strep pyogenes responsible for toxic shock like syndrome

A

erythrogenic toxin A

19
Q

which S. aureus proteins cleave desmoglein-1 protein and what happens thereafter

A

exfoliatoxin- separates epidermis to cause scalded skin syndrome
serine protease caises loss of adhesion of superficial dermis causing bullous impitigo

20
Q

what causes food poisoning in S. areus

A

enterotoxin

21
Q

what prevents opsinization and phagocytosis in S. aureus

A

Protein A

22
Q

how does S. aureus prevent the body from isolating infections

A

staphylokinase lyses thrombi

23
Q

treatments for S. aureus

A

vancomycin
linezolid
clindamycin

24
Q

what causes disruption of blood vessels in pseudamonas infections

A

elastase: serine protease cleaves desmoglein

25
Q

how does pseudomonas cause folliculitis

A

exotoxin A blocks EF-2, inhibiting protein synthesis
no protein synthesis contributes to cell necrosis
Necrosis at the site of follicle promotes inflammation at the follicle

26
Q

what causes sepsis in pseudomonas infections

A

exotoxin/ Lipid A

27
Q

what causes membrane degradation in pseudomonas infections

A

phospholipase c

28
Q

pseudomonas treatment

A

penicillin/ ticarcillin
cephalosporins
carbapenems

29
Q

shellfish/ marine environment

A

vibro vulnificus

30
Q

virulence factor of vibrio vulnificus

A

oxidase positive

31
Q

treatment for vibrio vulnificus

A

tetracyclines
ceftriaxone
fluoroquinolones

32
Q

animal bites

A

pasteurella

33
Q

pasteurella description

A

gram negative coccobacilli
encapsulated
facultative anaerobe with bipolar staining

34
Q

virulence factor of pasturella

A

endotoxin

35
Q

treatment for pasteurella

A

amoxicillin

36
Q

what forms of HPV cause verruca vulgaris

A

HPV types 1-4

37
Q

verruca vulgaris

A

common cutaneous warts

38
Q

morphology of HPV 1-4

A

hyperplasia of prickle cells

hyperkeratosis

39
Q

description of molluscum contagiosum

A

enveloped dsDNA Pxvirus

40
Q

largest DNA virus

A

Poxvirus

41
Q

how do you catch molluscum contagiosum

A

fomites
direct contact
scratched skin
humid climates

42
Q

morphology of molluscum contagiosum

A

nontender fleshy colored pearly dome shaped papules with central umbilication
hyperpigmentation
scarring

43
Q

Gram positive aerobic spore forming cocci

A

Bacillus anthracis

44
Q

describe cutaneous anthrax

A

painless papules that evolve into ulcers with surrounding erythema, then eventually a black necrotic eschar
When healed, it appears as hyperpigmented or scarred skin

45
Q

cutaneous anthrax treatment

A

fluoroquinolones or doxycycline

46
Q

diagnostics of anthrax

A

leukocytosis
increased transaminases
mediastinal widenind
ELISA immunohistochemistry

47
Q

Gram positive filamentous aerobic branching rod

A

Nocardia

48
Q

Nocardia diagnostics

A

acid fast

urease positive

49
Q

cutaneous nocardia clinical presentation

A

cellulitis
LAD
Lymphangitis

50
Q

Nocardia treatment

A

Bactrim
Carbapenems
Cephalosporins
Amikacin