Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Drug Action IV > Peptide Antimicrobials (MC) - Block 2 > Flashcards

Peptide Antimicrobials (MC) - Block 2 Flashcards

1
Q

Describe the characteristics of ABX mixutures of cyclic peptides?

A
  1. Uncommon a
  2. Common aa are with D conformation
  3. Pendant fatty acid chain
  4. Arichitecture protect from rapid metabolism
  5. Highly toxic, but reserved for serious situations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Because of the peptide stucture, what are strategies used to avoid proteolysis?

A
  1. Cyclization
  2. Use of abnormal amino acids (non-human/uncommon and D chemistry)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the general MOA of cyclopeptides?

A

Attach themselves to bacterial membrane and interfere with semipermeability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Common ADR of cyclopeptide?

A
  1. Nephrotoxicity
  2. Auditory nerve damage
  3. ANaphylactoid rx
  4. Drug rash (red man syndrome) -> slow infusion rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the function of the proline?

A

turns of molecule -> cyclic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

MOA of vanc?

A
  1. Binds to D-ala D-ala, blocking PBP from bind to PG by 5 H-bonds
  2. Indirectly inhibits transglycosylases -> inhibits linking between NAG-NAM
  3. Indirectly inhibits transpeptidases -> inhibits peptide cross-linking
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Resistnce to vanc?

A

Development of D-ala D-ala lactacte cell wall intermediate coded by van enzymes (A-E):
* Lowers binding affinity
* Loss of H-bonding affinity
* Van-associated enzymes that supply lactate for muation
* Avoparcin is a pesticide similar to vanc structure

Altered target in Enterococci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is VISA contributed to?

A

Thickened PG layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the uses for vanc?

A
  1. C. diff overgrowth
  2. MRSA
  3. Septicemia
  4. Endocarditis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the types of anaphylactoid rx?

A
  1. Hypotension
  2. Wheezing
  3. Dyspnea
  4. Uticaria
  5. Pruritus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is telavancin?

A

Same MOA as vanc, but also bidns to lipid II in cell membrane through lipophillic side chain (decylaminoethyl) -> depolarization of cells and disruption of barrier function

good for VISA and Sub MIC levels for 10hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is lipid II?

A

Cell wall precursor (immature peptidoglycan) -> binding causes disruption of PG synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What type of resistance is more prevailant?

A

Van A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What homolog is a mojority f Dalbavacin in?

A

B0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the structure of Dalbavancin?

A
  1. Lipid tail -> cell membrane and strengthn binding to D-ala D-ala
  2. Anudation of carboxyl group increases staphy activity
  3. Against Van B
17
Q

How does oritavancin differs from other peptides?

A
  1. Less floppy lipophilic ring: anchors the drug to membrane
  2. VanA and Van B activity
  3. Inhibtis bacterial RNA synthesis -> rapid bacterial eradication
18
Q

What is this

A

Cyclinc peptide

19
Q

What is the MOA of daptomycin?

A

Binds to cell membranes and causes depolization and loss of membran potential:
1. Interupts protein synthesis
2. DNA synthesis
3. RNA synthesis
4. Bactericidal

20
Q

Properties of daptomycin?

A
  1. Lipophilic with high PPB
  2. G+ bacteriacidal
  3. Targets phospholipid bilayer of membrane disrupting electrical potential
  4. C2+ is essential for action
  5. VRSA and MRSA
  6. Degredation by asp protease at 9-Asp
21
Q

Clincal uses of daptomycin?

A

Skin/ski structue the infection, bacterial endocarditis

22
Q

What can be a result of daptomycins dcreasing nerve conduction?

A
  1. Parestheisa
  2. Bell’s palsy
23
Q

What are the streptogramin?

A

Quinuprisin/Dalfopristin 30/70 (Synercid)

24
Q

What is the activity of synercid?

A
  1. Resistant G+
  2. VRE
25
Q

MOA of streptogramin?

A

Dalfopristin (type A): binds to 50S ribosomal subunit -> conformational change and provides higher bindign affinity for quinupristin
Quiniprisitn (type B): binds to 50s and inhibits protein synthesis

26
Q

Is there cross resistance with Synercid?

A

Quiniprist has cross resistance with macrolides and lincosamides, but not dalfopristin

27
Q

DDI of synecid?

A

Strong CYP3A4 inhibitor

28
Q

MOA of bacitracin?

A

Bind to phosphate group of the PP (Pyrophosphate)-C55 (Carbon 55) of the M- (NAM) and G- (NAG) subunits of the PG preventing dephosphorylation to the monophosphate (prevents translocation)

29
Q

MOA of polymixin? ADR?

A

Binds to phosphate group on the cytoplasmic membrane -> break down in membrane integrity

ADR: neuro and nephrotox

30
Q

What is polymixin used for?

A
  1. Serious UTI
  2. Meningitis
  3. Septicemia
  4. Bladder irrigation

P. aeuriginosa

31
Q

sMOA of colistin

A

Competitively displaces divalent cations (Ca and Mg) from the phosphate groups of membrane lipids -> disruption of outer cell membrane -> leakage of intracellular contents and bacterial death

32
Q

What is the structure that causes disrupion of phospholipid membrane -> lethal bacterial death?

A

DAB

Drug Action IV (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions