1

Question 1

superantigen exotoxins are secreted by

Answer 1

1. streptococcus pyogenes

2. staphylococcus aureus

Question 2

superantigens function by

Answer 2

cross linking the alpha chain of MHC2 on the APC with the variable region of the B-chain of T cell receptors on CD4 Th cells.

This creates polyclonal T cell activation, leading to increased I-2 and IFN-y.

The resulting release activates m0 and promotes the release of proinflammatory cytokines like IL-1, IL-6, TNFa

Question 3

Staphylococcus arues superantigen exotoxins

Answer 3

1. TSST–Toxic shock syndrome is responsible for TSS

2. enterotoxin is food poisoning

Question 4

Streptococcus pyogenes

Answer 4

1. SpeA is TSLC (toxic shock like syndrome) and the rash in scarlet fever
2. SpeB is necrotizing fascitis
3. SpeA,B,C are scarlet fever

Question 5

lab values in rickets

Answer 5

1. decreased 25(OH) vitamin d
2. decreased ca
3. decreased phosphate
4. increased alkaline phosphatase
5. increased PTH

Question 6

treat nocardia

Answer 6

bactrim

Question 7

legionnaire’s disease treatment

Answer 7

macrolides and respiratory tract: fluoroquinolones