export_ssti bacteria i

Question 1

Minimum diagnostic criteria for skin/soft tissue infection (SSTI)

Answer 1

Erythema
Edema

Warmth

Pain/tenderness

Question 2

Superficial SSTI

Answer 2

Erysipelas

Question 3

Deeper SSTI (dermis, subQ)

Answer 3

Cellulits

Question 4

Deepest SSTI (muscle, etc.)

Answer 4

Necrotizing fasciitis

Question 5

Impetigo cause

Answer 5

S. aureus

Question 6

Impetigo features

Answer 6

Superficial
“Honey crusts”

Most commonly around the mouth

Most common bacterial infection in children

Question 7

Bullous impetigo features

Answer 7

Blisters are cloudy, can rupture

Question 8

Bullous impetigo virulence

Answer 8

Exfoliative toxin of S. aureus

Question 9

Ecthyma

Answer 9

Deeper form of impetigo, scarring and ulceration

Punched-out ulcerative lesions

Question 10

Furuncle (boil) causative agent

Answer 10

S. aureus

Question 11

Furuncle features

Answer 11

Abscess of hair follicle

Large, painful, raised nodules

Question 12

Carbuncle

Answer 12

Multiple furuncles that coalesce

Question 13

Carbuncle defining feature

Answer 13

Chills and fever

Question 14

Folliculitis

Answer 14

Infection of hair follicles

Various bacteria and fungi

Question 15

Erysipelas

Answer 15

Acute skin infection

Involved skin is distinct from uninvolved skin

Question 16

Erysipelas cause

Answer 16

S. pyogenes

Question 17

Cellulitis

Answer 17

Involved skin is NOT differentiated from uninvolved skin

Question 18

Cellulitis causative agent

Answer 18

Many microbes

Often GAS or S. aureus

Question 19

Paronychia

Answer 19

Superficial infection or abscess of nailfolds

Acute or chronic

Question 20

Acute paronychia

Answer 20

Acutely painful abscess in nailfold

Most common cause is S. aureus

Question 21

Chronic paronychia

Answer 21

Longer than 6 weeks

Often the result of a C. albicans infection

Question 22

Necrotizing fasciitis

Answer 22

Destruction of muscle and fat
Toxicity, multiorgan failure, death

Antibiotics and surgical debridement

Question 23

S. aureus features

Answer 23

Gram-positive cocci
Catalase positive

Found in skin/mucous membranes

Coagulase positive (unlike other Staph)

Beta-hemolytic

Question 24

Strep. pyogenes features

Answer 24

Gram-positive cocci

Catalase negative

Question 25

Pseudomonas aeruginosa features

Answer 25

Gram-negative rod

Question 26

S. aureus virulence factors

Answer 26

Capsule Biofilm Teichoic acid Protein A Cytotoxins Exfoliative toxins Enterotoxins TSST Extracellular hydrolases

Question 27

S. aureus capsule

Answer 27

Anti-phagocytic

Question 28

S. aureus peptidoglycan

Answer 28

Endotoxin-like activity

Question 29

S. aureus teichoic acid

Answer 29

Adhesion

Question 30

S. aureus protein A

Answer 30

Inhibits Ab mediated clearance by binding IgG Fc domain

Question 31

S. aureus alpha cytotoxins

Answer 31

Pore-forming toxin | Allows for bacteria to get into cell, as well as resulting in lysis

Question 32

S. aureus exfoliative toxins

Answer 32

ETA and ETB | Serine proteases that split interepidermal junctions

Question 33

S. aureus enzymes

Answer 33

Hydrolyze host tissue to aid in the spread of the bacteria in the body

Question 34

S. aureus diseases

Answer 34

``` Toxin mediated (scalded skin syndrome, food poisoning) Suppurative (impetigo, folliculitis, etc.) ```

Question 35

S. aureus scalded skin syndome (SSSS) virulence

Answer 35

Caused by ETA and ETB

Question 36

Important diagnostic features of SSSS

Answer 36

Staph not culturable from skin (toxin mediated) | No leukocytes

Question 37

Treat SSSS

Answer 37

Neutralizing Abs result in resolution of toxic process

Question 38

Nikolsky sign

Answer 38

Minimal pressure results in skin exfoliation

Question 39

MRSA

Answer 39

Methicillin-resistant S. aureus

Question 40

MRSA virulence factor

Answer 40

MecA gene 

Question 41

MecA gene

Answer 41

Encodes a new penicillin-binding protein on methicillin, etc. which results in a low affinity to the bacteria

Question 42

Treat MRSA

Answer 42

Vancomycin

Question 43

Treatment for S. aureus infections

Answer 43

Nafcillin | Oxacillin

Question 44

Osteomyelitis

Answer 44

Bone pain Fever Swelling Malaise

Question 45

Osteomyelitis cause

Answer 45

Almost always by a bacterial infection

Question 46

Septic arthritis features

Answer 46

Painful, erythematous joint with purulent material | Usually in large joints

Question 47

Most common causes of septic arthritis

Answer 47

S. aureus in children | N. gonorrhoeae in sexually active persons