cell wall inhibitor

Question 1

How Do Beta Lactams Kill Bacteria?

Answer 1

inhibit cell wall synthesis- inhibit the formation of peptidoglycan in which without it the bacteria would lyse

Question 2

provides stability by virtue of highly cross-linked latticework structure.

Answer 2

peptidoglycan

Question 3

Beta-lactams inhibit the family of enzymes involved in ___________

Answer 3

final stage of cell wall synthesis

transpeptidation or cross linkage

Question 4

how are the enzymes involved in the final stage of cell wall synthesis detected

Answer 4

by penicillin binding proteins that covalently bind to the enzymes

Question 5

Beta lactams lead to _____________ resulting in cell wall digestion and lysis of bacterial cell

Answer 5

dysregulation of autolysins

Question 6

Beta-lactams are generally

Answer 6

bactericidal

Question 7

3 mechanisms of resistance

Answer 7

1. inactivation of antibiotic by a bacterial enzyme called beta-lactamase
2. alteration of target site- low affinity of PBs
3. decreased penetration to target site- such as gram negative bacili

Question 8

B-lactam antibiotics work best at

Answer 8

time-dependent killing: lower yet more frequent dosing effective … just above the MIC but steady dose

• they have a short half life
• excreted by the kidneys

Question 9

allergic reactions in beta lactams

Answer 9

common:

1. immediate allergic rxn.- IgE mediated (less common)
2. late allergic rxn (more common)

Question 10

Narrow-spectrum
Low cost
Favorable therapeutic index
Excellent tissue penetration

Answer 10

penicillin

Question 11

what do all of these have in common:

Staphylococcus aureus
Neisseria gonorrhoeae
Streptococcus pneumoniae

Answer 11

they are bacteria that we no longer use penicillin to treat due to increase resistance issues

Question 12

Main use is against penicillinase-producing Staphylococcus aureus
and it is a truly narrow-spectrum agent

Answer 12

oxacillin

• synthetic penicillin created to treat a. aureus but there are some activity to streptococci

Question 13

oxacillin active against MRSA?

Answer 13

nope

Question 14

which is the only agent in the beta lactam family of antibiotics that treat MRSA?

Answer 14

ceftaroline

Question 15

• Similar spectrum of activity as penicillin plus
• More active against enterococcus
• Active against Listeria monocytogenes
• Additional coverage of some gram negative bacilli: Haemophilus influenzae, some E. coli, Proteus species.

Answer 15

Amoxicillin

Question 16

ampicillin is used to treat

Answer 16

meningitis secondary to listeria monocytogenes

Question 17

Due to the potential production of beta-lactamases, all Haemophilus isolates should undergo sensitivity testing

Answer 17

yep

Question 18

Clavulanic acid and sulbactam are potent inhibitors of many beta-lactamases
thus when combined with beta-lactamases they

Answer 18

increase the spectrum

By a complex interaction, it functions as a suicide inhibitor, meaning it serves as a target for the beta-lactamase enzyme thereby blocking the enzymatic breakdown of amoxicillin by beta-lactamases. This leaves the amoxicillin intact and able to inhibit the bacteria.

Question 19

Clinical Uses of Intermediate Spectrum β-Lactams + β-Lactamase Inhibitors: Ampicillin-sulbactam

Answer 19

intra-abdominal and pelvic infections

Question 20

Active against many gram negative organisms including Pseudomonas aeruginosa and Enterobacter spp.
Active against gram positive organisms such as streptococci

Answer 20

broad-spectrum penicillin

Question 21

Broad Spectrum PCNs: Addition of β-Lactamase Inhibitors

Answer 21

are used as well in intraabdominal infections but this one is preferred is there are resistant gram negative organism

Question 22

In diverticulitis, antibiotics should cover “mixed flora” – gram positives, gram negatives and anaerobes

thus what is a good choice

Answer 22

ampicillin-sulbactam

Question 23

spectrum of B-lactam ring anitbiotics are determined by the

Answer 23

side rings

Question 24

serum sickness is an adverse effect of beta lactams… what type of rxn is it?

Answer 24

it is a late allergic rxn thus we tend to see fever, rash, arthritis and circulating immune complexes

Question 25

moribiliform rash beta lactam adverse effect

Answer 25

delayed rxn

Question 26

what is the antibiotic that is preferred for Staph. aureus- methicillin sensitive

Answer 26

oxacillin

Question 27

antibiotic against Pseudomona aurginosa

Answer 27

piperacillin/tazobactam