Microbio

Question 1

Mechanism of metronidazole

Answer 1

Unravels DNA and breaking strands

Question 2

Mechanism of bacitracin

Answer 2

Prevents mucopeptide transfer into growing cell wall

Question 3

Mechanism of sulfamethoxazole

Answer 3

Compete with PABA to inhibit DHF synthesis, an intermediate step

Question 4

What can you do to increase the plasma concentration of imipenem?

Answer 4

Coadminister cilastatin. Prevents renal metabolism of imipenem.

Question 5

Two mechanisms of penicillin resistance

Answer 5

1. beta lactamases

2. modification of penicillin binding proteins (MRSA does this to resist nafcillin, oxacillin)

Question 6

Cycloserine mechanism

Answer 6

Inhibits incorporation of DAla during cell wall synthesis. BUT high ototoxicity rarely used.

Question 7

Mechanism of polymyxin

Answer 7

binds to and disrupts permeability of cytoplasmic membrane

Question 8

Mechanism of resistance to aminoglycosides

Answer 8

inactivation by a modifying enzyme. These will phosphorylate/adenylate/acetylate the antibiotic.

Question 9

mechanism of daptomycin

Answer 9

depolarizes cellular membrane by creating transmembrane channels

Question 10

side effect daptomycin

Answer 10

myopathy+CPK elevation

inactivated by pulmonary surfactant

Question 11

Linezolid mechanism

Answer 11

inhibits bacterial protein synthesis by binding 50S subunit

Question 12

Side effects linezolid

Answer 12

thombocytopenia and optic neuritis

Question 13

side effect of vancomycin

Answer 13

red man syndrome nephrotoxicity

Question 14

penicillins are structural analogs of

Answer 14

D-Ala-D-Ala

Question 15

Sulfonamide mechanism

Answer 15

competes with PABA for incorporation into folic acid

Question 16

Condyloma lata

Answer 16

wart like genital lesion that shows up during secondary syphilis

Question 17

tertiary syphilia

Answer 17

Gummas (necrotizing granulomas on skin), with neuro sx, cardiovascular involvement. If neuro sx, the lesion has to be a gumma!