export_ssti bacteria ii

Question 1

Alpha-hemolysis

Answer 1

Green coloration

Question 2

Beta-hemolysis

Answer 2

Complete hemolysis

Question 3

Gamma-hemolysis

Answer 3

No color change or lysis

Question 4

Lancefield Ags

Answer 4

A, B, and D

Distinguish between Strep. species

Question 5

A Lancefield Ag

Answer 5

Found in S. pyogenes

Question 6

B Lancefield Ag

Answer 6

S. agalactiae

Question 7

D Lancefield Ag

Answer 7

S. bovis

Enterococcus

Question 8

Strep. without Lancefield Ag

Answer 8

S. pneumoniae

S. mutans

Question 9

Group A strep disease

Answer 9

S. pyogenes

Strep throat

Question 10

S. pyogenes features

Answer 10

Beta-hemolytic

Sensitive to Bacitracin

Question 11

S. pyogenes virulence factors

Answer 11

Capsule
Adhesins (F and M protein, LTA)

Toxins (streptolysin O and S, superantigens)

Question 12

LTA

Answer 12

Adhere to fibronectin

Question 13

F and M protein

Answer 13

Invasion of epithelial cell

Question 14

M protein

Answer 14

Anti-phagocytic
Inhibits complement

Facilitates cell invasion (fibrinogen, Ig, factor H)

Question 15

Streptolysin O and S

Answer 15

Pore forming toxins

Allow invasion and destruction of cells/tissues

Question 16

Strep. superantigens

Answer 16

SPEs

Proinflammatory cytokine response

Question 17

C5a peptidase

Answer 17

Degrades C5a (chemoattractin that brings PMNs to site of infection)

Question 18

SSTI by S. pyogenes

Answer 18

Impetigo
Erysipelas

Cellulitis

Necrotizing fasciitis

Question 19

What is the most common cause of cellulitis?

Answer 19

S. pyogenes

Question 20

Diagnostic symptom of necrotizing fasciitis

Answer 20

Pain and tenderness are usually severe

Question 21

Difference between cellulitis and necrotizing fasciitis

Answer 21

Cellulitis generally looks worse early on, and is less painful

Question 22

Treatment of necrotizing fasciitis

Answer 22

Debridement of area

Antibiotics are supplemental

Question 23

Scarlet fever

Answer 23

Complication of GAS pharyngitis
Caused by SPE toxin

Diffuse erythematous rash

Question 24

Acute rheumatic fever

Answer 24

Complication of GAS pharyngitis

Cross-reactive Abs attack joints, heart valves, etc.

Question 25

Acute poststrep glomerulonephritis (APSGN) cause

Answer 25

Complication of either GAS pharyngitis OR SSTI
Type III hypersensitivity

Ag mimicry of M protein or streptokinase

Question 26

APSGN symptoms

Answer 26

Hematuria, edema, HTN

Reduced serum complement

Question 27

Difference between Strep. and Staph. TSS

Answer 27

Strep. often comes with bacteremia and necrotizing fasciitis, and is the result of SPEs

Question 28

Diagnose and treat GAS infection

Answer 28

Anti-streptolysin O Abs in serum

Penicillin

Question 29

Pseudomonas aeruginosa features

Answer 29

Oxidase positive
Antibiotic resistance

Minimalist

Production of pyocyanin pigment

Primarily nosocomial and opportunistic

Question 30

P. aeruginosa virulence factors

Answer 30

Mucoid polysaccharide capsule (alginate)
Adhesins

Toxins (ETA, T3SS)

Question 31

ETA

Answer 31

AB toxin

Inactivates EF2 - blocks protein synthesis

Question 32

P. aeruginosa SSTIs

Answer 32

Infections in burn wounds
Folliculitis

Osteochondritis (following traumatic injury)

Ecthyma gangrenosum

Question 33

Ecthyma gangrenosum

Answer 33

Infection of blood vessels resulting in characteristic necrotic skin lesions

Question 34

“Green nails”

Answer 34

Biofilm of P. aeruginosa on the nails

Often associated with previous condition of candidal paronychia

Question 35

Webspace intertrigo

Answer 35

Macerated and eroded skin between skin folds, most commonly associated with P. aeruginosa

Question 36

Treatment of P. aeruginosa

Answer 36

Aminoglycosides and beta-lactam

Antibiotic resistance is a problem