Chapter 37. Principles of Antimicrobial Therapy

Question 1

Inhibitors of cell
membrane function

Answer 1

Isoniazid
Amphotericin B
Polymyxins

Question 2

Inhibitors of
nucleic acid
function or
synthesis

Answer 2

Fluoroquinolones
Rifampin

Question 3

Inhibitors of
protein synthesis

Answer 3

Macrolides
Tetracyclines
Aminoglycosides
Linezolid
Clindamycin
Chloramphenicol

Question 4

Inhibitors of cell
wall synthesis

Answer 4

Beta lactam
Vancomycin
Daptomycin
Telavancin
Fosfomycin

Question 5

Inhibitors of
metabolism

Answer 5

Sulfonamides
Trimethoprim

Question 6

Some mechanisms of resistance to antibiotics.

Answer 6

Alteration in the target
enzyme, DNA gyrase,
has resulted in
resistance to uoro-
quinolones.

b-Lactams enter gram-
negative cells through
porin channels.
Enterobacter is largely
resistant to cephalo-
sporins by producing
b-lactamases. However,
resistant organisms
may also have altered
porin channels through
which cephalosporins
do not pass.

Tetracycline was
eective against gyne-
cologic infection due
to Bacteroides, but now
these organisms are
resistant due to the
presence of plasmid-
mediated protein that
promotes eux of the
drug.

b-Lactamases (penicillinases)
destroy antibiotic with the
b-lactam nucleus.
Neisseria gonorrhoeae
is now largely resistant to
penicillin because of
penicillinase activity.