Inhibitors Of Cell Wall Synthesis

Question 1

Beta-Lactam structure

Answer 1

Essential for activity
structural analog of D-Ala-D-ALA residue of NAM/NAG

Question 2

Beta-lactam ring has high affinity for

Answer 2

Bacterial PBPs

Question 3

Beta-lactam mechanism of action

Answer 3

T>MIC
Irreversible inhibition of PBPs=autolysin activation

Question 4

Penicillin resistance due to

Answer 4

decreased permeability
Mutation in PBPs (G+ strains)
Enzymatic inactivation (beta-lactamase, ex.ESBL)

Question 5

Penicillin G and V are active against

Answer 5

G+ cocci/bacilli
Anaerobes
NOT G- cocci, beta-lactamase producing strains

Question 6

Penicillin G is given

Answer 6

IV or IM

Question 7

Penicillin V is given

Answer 7

Orally

Question 8

Nafcillin is active against

Answer 8

PCN G-resistant methicillin susceptible staph (MSSA) and streptococci

Question 9

Methicillin is not used because

Answer 9

It causes acute interstitial nephritis

Question 10

MRSA has emerged due to

Answer 10

Altered PBPs

Question 11

PBP2/mecA is resistant to all beta-lactams except

Answer 11

Ceftaroline

Question 12

Amoxacillin is active against G- bacilli due to

Answer 12

Charged amino group that enables transfer though outer membrane porins

Question 13

Piperacillin-tazobactam has better activity against G- strains (notably P. Auriginosa) due to

Answer 13

Modified amino-PCN R group

Question 14

Clavulate and tazobactam role

Answer 14

Protect antibiotics from inactivation by beta-lactamases in G- bacteria

Question 15

Beta lactamase have _ half lives

Answer 15

Short

Question 16

Penicillin G benzathine is given_

Answer 16

IM weekly

Question 17

_ prolongs penicillin duration by extending half life

Answer 17

Probenecid

Question 18

Adverse reactions of penicillins include

Answer 18

Nausea/diarrhea
Maculopapular rashes (amino penicillins-amoxacillin, esp in people with EBV)
Allergy- urticarial rash

Question 19

Aminopenicillins

Answer 19

Amoxacillin

Question 20

Extended-spectrum penicillins (aka anti-pseudomonal)

Answer 20

Piperacillin-tazobactam

Question 21

Beta-lactamase inhibitors

Answer 21

Clavulanate
Tazobactam

Question 22

Cephalosporin resistance due to

Answer 22

Production of beta-lactamases and altered PBPs

Question 23

1st generation cephalosporin

Answer 23

Ceftazolin

Question 24

Ceftazolin is used for

Answer 24

Prophylaxis against surgical site infections (MSSA and strep)

Question 25

2nd generation cephalosporin

Answer 25

Cefoxitin (subgroups- cephamycins and cephalosporins)

Question 26

3rd generation cephalosporin

Answer 26

Ceftriaxone

Question 27

Ceftriaxone is useful for treating

Answer 27

G- meningitis (ESBL bacteria are resistant)

Question 28

5th generation cephalosporin

Answer 28

Ceftaroline

Question 29

_ is the only beta lactam active against MRSA

Answer 29

Ceftaroline

Question 30

Carbapenems

Answer 30

Imipenem-cilastatin

Question 31

_ are highly resistant to inactivation by beta lactamase

Answer 31

Carbapenems

Question 32

Carbapenems are given

Answer 32

Parenterally and eliminated by kidneys

Question 33

Imipenem is combined with cilastatin to

Answer 33

Block host renal inactivation

Question 34

Carbapenems are used for

Answer 34

Resistant infections Anaerobics Mixed infections

Question 35

Monobactams

Answer 35

Aztreonam

Question 36

Aztreonam is only active against

Answer 36

G- aerobes

Question 37

Glycopeptides

Answer 37

Vancomycin

Question 38

Glycopeptides mechanism of action

Answer 38

Bactericidal AUC/MIC Binds D-ALA-D-ALA of NAM blocking addition to the chain

Question 39

Vancomycin is only active against

Answer 39

G+ Only given orally for C. Diff

Question 40

Vacomyicin is _toxic

Answer 40

Oto and nephro Can also cause flushing reaction

Question 41

Phosphoenolpyruvate analogs

Answer 41

Fosfomycin

Question 42

Fosfomycin mechanism of action

Answer 42

Inhibits production of Mur A enzyme which synthesizes NAM Enter bacteria via glycerophosphate transporter (not present in mammals

Question 43

Fosfomycin is only used against

Answer 43

Urinary pathogens

Question 44

Beta lactam inhibitors of cell wall synthesis

Answer 44

Penicillin V, G Nafcillin Amoxicillin (-clavulonate) Piperacillin-tazobactam Cefazolin Cefoxitin Ceftriaxone Cefepime Ceftaroline Imipenem-cilastatin Aztreonam

Question 45

Non-beta-lactam cell wall synthesis inhibitors

Answer 45

Vancomycin Fosfomycin