Bacterial infections of skin and soft tissue II

Question 1

Is strep pyogenes SENSITIVE to bacitracin? What about most beta hemolytic strep?

Answer 1

1. Yes 2. No

Question 2

What are the GAS virulence factors?

Answer 2

Capsule, adhesins, toxins

Question 3

What are the GAS adhesins?

Answer 3

F protein, M protein, LTA

Question 4

What are the GAS toxins?

Answer 4

Streptolysin O and S, superantigens

Question 5

What is the role of the GAS adhesin LTA?

Answer 5

Adheres to fibronectin on epithelial cell surface

Question 6

What is the role of F protein and M protein GAS adhesins?

Answer 6

Invasion of epithelial cell

Question 7

What is the most common cause of cellulitis?

Answer 7

Strep pyogenes

Question 8

Rheumatic fever is what type of hypersensitivity response to GAS?

Answer 8

Type III

Question 9

What makes strep TSS different from staph TSS?

Answer 9

Many patients with streptococcal disease are bacteremic and many have necrotizing fasciitis

Question 10

What is the gram stain for pseudomonas aeruginosa?

Answer 10

Gram negative

Question 11

What is the oxidase test for pseudomonas?

Answer 11

Positive

Question 12

What are the pseudomonas virulence factors?

Answer 12

Mucoid polysaccharide capsule, adhesins, secreted toxins and enzymes, antibiotic resistance

Question 13

What comprises the pseudomonas polysaccharide capsule?

Answer 13

Alginate

Question 14

What are the pseudomonas aeruginosa toxins?

Answer 14

Exotoxin A and T3SS

Question 15

What is the function of pseudomonas aeruginosa exotoxin A?

Answer 15

A/B toxin - inactivates EF-2 via ADP ribosylation - blocks protein synthesis

Question 16

When does ecythma gangrenosum occur?

Answer 16

Pseudomonas septicemia

Question 17

What is the most common cause of webspace intertrigo?

Answer 17

Pseudomonas aeruginosa

Question 18

What is the treatment for pseudomonas aeruginosa?

Answer 18

Combination therapy with aminoglycosides and beta lactams