Chapter 150 - Superficial And Cutaneous Infections part II

Question 1

2 main families of pore forming toxins (2)

Answer 1

1. Alpha hemolysin (alpha toxin)

2. Leukotoxins (Panton Valentine Leukocidin, gamma hemolysin, leukocidin ED, and leukocidin AB)

Question 2

Matching type

1. Alpha hemolysin
2. Leukocidin AB
3. Leukocidin ED
4. PVL

A. ADAM 10
B. C5a receptors
C. CD 11b
D. CCR5, CXCR1, CXCR2

Answer 2

A
C
D
B

Question 3

Toxins associated with virulence of CA MRSA (2)

Answer 3

Alpha toxin

Panton Valentine Leukocidin

Question 4

High serum antibody titers against ___ correlate with protection against recurrent S. Aureus SSTIs

Answer 4

Alpha toxin

Question 5

Serine proteases that target desmoglein 1

Answer 5

Exfoliatin

Question 6

Most common exfoliatin located in S. Aureus bacteriophages (2)

Answer 6

ETA and ETB

Question 7

Exfoliatin located in bacterial chromosome

Answer 7

ETD

Question 8

Have the ability to nonspecifically activate T cells by interacting with HLA-DR molecule

Answer 8

Superantigens

Question 9

Toxin largely responsible for S. Aureus TSS

Answer 9

TSST 1

Question 10

Increase severity of AD by driving cutaneous inflammation, promoting TH2 responses and inducing production of IgE antibodies

Answer 10

Staphylococcal enterotoxin B

Question 11

Block complement and formylnpeptide receptors of CXCR2 neutrophil attracting chemokines

Answer 11

CHIPS (chemotaxis inhibitory protein of S. Aureus)

ScpA (staphopain A)

Question 12

Inhibits neutrophil extravasation from blood vessels (2)

Answer 12

Staphylococcal superantigen like 5,11

SSL5,11

Question 13

Blocks P selectin and ICAM 1 to inhibit meutrophil rolling and adhesion to endothelium

Answer 13

Eap (extracellular adherence protein)

Question 14

Yellow carotenoid pigment responsible for golden color of S. Aureus colonies

Answer 14

Staphyloxanthin

Question 15

Degrade neutrophil extracellular traps to prevent killing of S. Aureus

Answer 15

Adenosin synthase A (AdsA)
Staphylococcal nuclease (Nuc)

Question 16

TLR which recognizes S aureus lipoproteins, lipoteichoic acid and peptidoglycan, and nucleotide binding oligomerization domain containing protein (NOD2)

Answer 16

TLR2

Question 17

Critical cytokine for inducing neutrophil recruitment and abscess formation to site of S. Aureus infection in skin

Answer 17

IL1B

Question 18

Key role in neutrophil recruitment

Answer 18

IL17

Question 19

Biposy or aspiration of furuncles, carbuncles is recommended in (2)

Answer 19

immunocompromised patients

patients with fever and neutropenia

Question 20

Topical treatments for impetigo (3)

Answer 20

Mupirocin 2% ointment BID for 5-7 days
Retapamulin 1% ointment BID for 5-7 days
Fusidic acid 1% cream BID- QID

Question 21

Oral treatment for impetigo, ecthyma, uncomplicated folliculitis (5)

Answer 21

Dicloxacillin 250-500mg PO QID
Cephalexin 500mg PO QID/50-100mkday
Erythromycin 250-500mg PO QID/40mkday
Co-Amoxiclav 25mkday TID
Clindamycin 15mkday TID-QID

Question 22

Treatment for CA-MRSA (3)

Answer 22

Doxycyline 100mg BiD
Clindamycin 300-450mg TID-QID/ 20-40mkday
TMP-SMX 8-12mkday

Question 23

CA- MRSA should be suspected in ALL serious purulent infections.
True or False

Answer 23

True

Question 24

For recurrent furuncles, carbuncles, and abscesses at same site of prior infection, source of ff should be considered (3)

Answer 24

Hidradenitis suppurativa
Pilonidal cyst
Foreign body

Question 25

Nasal decolonization can be achieved with

Answer 25

Mupirocin 2% ointment BId for 5-10 days
Chlorhexidine cleansing solution for 5-14 days
Bleach baths twice weekly for 3 mos
Rifampin 30mg BiD

Question 26

Typical regimen for bleach bats

Answer 26

1tsp of bleach/gallon of water

1/4 cup if bleach / 1/4 bathtub of water (13 gallons of water)