Bacterial infections of skin and soft tissue III

Question 1

What virulence factors are responsible for causing disease in clostridium infection?

Answer 1

Hemolysin, neurotoxin, enterotoxin

Question 2

What is the most important clostridium toxin?

Answer 2

Alpha toxin

Question 3

What are the most susceptible types of wounds for clostridium perfringens infection?

Answer 3

Traumatic wounds and surgical wounds

Question 4

What are crepitations?

Answer 4

Gas production from clostridium perfringens infection

Question 5

What is the cause of gas gangrene?

Answer 5

Clostridium perfringens

Question 6

How is clostridium perfringens detected microscopically?

Answer 6

Gram positive rods WITHOUT leukocytes

Question 7

What are the two tetanus toxins?

Answer 7

1. Tetanolysin - oxygen labile 2. Tetanospasmin - heat labile neurotoxin

Question 8

What is the gram stain for mycobacterium?

Answer 8

Gram positive (weakly)

Question 9

What is the shape of mycobacterium?

Answer 9

Rod

Question 10

What is the mycobacterium analog of LPS?

Answer 10

Lipoarabinomannan

Question 11

What do macrophages release in response to mycobacterium tuberculosis infection?

Answer 11

IL-12 and TNFa

Question 12

What is the T cell reaction in response to mycobacterium tuberculosis infection?

Answer 12

Differentiation into Th1 and production of IFNy

Question 13

What is the treatment for TB?

Answer 13

First line course of isoniazid + rifampin + ethambutol + pyrazinamide for 6-9 months

Question 14

What cells does mycobacterium leprae target?

Answer 14

Macrophages and Schwann cells

Question 15

What is the unique antigen associated with mycobacterium leprae?

Answer 15

Phenolic glycolipid (PGL-1)

Question 16

Are antibodies useful against leprosy?

Answer 16

No - intracellular pathogen

Question 17

Which immune response is worse in a mycobacterium leprae infection?

Answer 17

Th2

Question 18

Will people with a Th2 immune response to mycobacterium leprae respond to lepromin?

Answer 18

No

Question 19

Will people with a Th1 immune response to mycobacterium leprae respond to lepromin?

Answer 19

Yes

Question 20

What is the gram stain for nocardia?

Answer 20

Gram positive

Question 21

What is the shape of nocardia?

Answer 21

Rod

Question 22

What is the acid fast stain for nocardia?

Answer 22

Weakly acid fast

Question 23

What is the cause of mycetomas?

Answer 23

Nocardia

Question 24

What are the cutaneous infections caused by nocardia?

Answer 24

Lymphocutaneous disease, cellulitis, subcutaneous abscesses

Question 25

What is the most important indicator of nocardia infection during a history?

Answer 25

Exposure to environment (gardening, farming)

Question 26

What is the treatment for nocardia?

Answer 26

TMP-SMX

Question 27

What is the most common presentation of actinomyces infection?

Answer 27

Cervicofacial actinomyces

Question 28

What are common etiologies of cervicofacial actinomyces?

Answer 28

Poor dental hygiene and/or dental surgery

Question 29

How are nocardia and actinomyces differentiated?

Answer 29

Actinomyces do not stain with modified acid fast stain

Question 30

What is the treatment for actinomyces?

Answer 30

Penicillin

Question 31

What are the four key elements of acne vulgaris pathogenesis?

Answer 31

1. Follicular epidermal hyperproliferation 2. Excess sebum production 3. Inflammation 4. Presence and activity of proprionibacterium acnes

Question 32

What is the gram stain for proprionibacterium acnes?

Answer 32

Gram positive

Question 33

What is the shape of proprionibacterium acnes?

Answer 33

Rod

Question 34

What are the leading causes of gingivitis and periodontitis?

Answer 34

Poryphyromonas gingivalis and treponema denticola

Question 35

What is the main cause of dental caries?

Answer 35

Strep mutans - acids produced by strep mutans react with species in the plaque biofilm