Antimicrobials

Question 1

Inhibition of bacterial cell-wall synthesis

Answer 1

Penicillins, cephalosporins, imipenem/

meropenem, aztreonam, vancomycin

Question 2

Inhibition of bacterial protein synthesis

Answer 2

Aminoglycosides, chloramphenicol, macrolides, tetracyclines, streptogramins, linezolid

Question 3

Inhibition of nucleic synthesis

Answer 3

Fluoroquinolones, rifampin

Question 4

Inhibition of folic acid synthesis

Answer 4

Sulfonamides, trimethoprim, pyrimethamine

Question 5

Production of beta-lactamases, which cleave the beta-lactam ring structure; change in penicillin-binding proteins; change in porins

Answer 5

Penicillins and cephalosporins

Question 6

Formation of enzymes that inactivate drugs via conjugation reactions that transfer acetyl, phosphoryl, or adenylyl groups

Answer 6

Aminoglycosides (gentamicin, streptomycin, amikacin, etc.)

Question 7

Formation of methyltransferases that alter drug binding sites on the 50S ribosomal subunit Active transport out of cells

Answer 7

Macrolides (erythromycin, azithromycin, clarithromycin, etc.) and clindamycin

Question 8

Increased activity of transport systems that “pump” drugs out of the cell

Answer 8

Tetracyclines

Question 9

Change in sensitivity to inhibition of target enzyme; increased formation of PABA; use of exogenous folic acid

Answer 9

Sulfonamides

Question 10

Change in sensitivity to inhibition of target enzymes; increased activity of transport systems that promote drug efflux

Answer 10

Fluoroquinolones

Question 11

Formation of inactivating acetyltransferases

Answer 11

Chloramphenicol

Question 12

Organisms not covered by cephalosporins are “LAME”:

Answer 12

Listeria monocytogenes Atypicals (e.g.,Chlamydia,

Mycoplasma) MRSA Enterococci