Flashcards in Cell Wall Synthesis Inhibitors Deck (17):
1
Betalactam Antibiotics
Penicillin
2
Penicillin MOA
Penicillins are bactericidal
Bind to penicillin-binding proteins and inactivate transpeptidase,
which prevents the cross linking of peptidoglycan chains in the bacterial cell wall,
leading to loss of cell rigidity and cell death.
3
Penicillin Mechanism of Resistance (MOR)
Penicillinases (b-lactamases) break the betalactam ring: Staphylococci
Alteration of penicillin-binding proteins: Staph. Aureus: MRSA, penicillin resistant pneumococci
Reduced permeability in Gram-negative cell membranes (change in porin structure): Pseudomonas
4
Bactericidal antibiotics:
a) How do they work?
b) examples
a) Cause death of the microorganism
b)
• Penicillins
• Aminoglycosides
• Cephalosporins
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Bacteriostatic antibiotics:
a) What do they do?
b) examples
a) Inhibits the growth of the microorganism
b)
• Sulfonamides,
• Tetracyclines
• Erythromycin
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Antimicrobials that inhibit cell wall synthesis
• Penicillins
• Cephalosporins
• carbapenems
• monobactum
• Vancomycin
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Antimicrobials that Inhibit bacterial protein Synthesis
• Tetracyclines
• macrolides
• Chloramphenicol
• Aminoglycosides
• streptogramins
• linezolid
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Antimicrobials that inhibit nucleic acid synthesis
• Fluroquinolones
• rifampin
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Which drug has this MOA:
Bind to penicillin-binding proteins and inactivate transpeptidase,
which prevents the cross linking of peptidoglycan chains in the bacterial cell wall,
leading to loss of cell rigidity and cell death.
Penicillin
10
Staphylococci MOA
Penicillinases (b-lactamases) break the betalactam ring
11
Feature of Gram + wall
• teichoic acid (causes endotoxic shock)
• thick peptidoglycan layer and no outer membrane.
12
Features of Gram - cell wall
• outer membrane,
• then peptidoglycan layer
• LPS (causes endotoxic shock)
13
Which drugs have this MOR:
Alteration of penicillin-binding proteins
• Staph. Aureus: MRSA,
• penicillin resistant pneumococci
14
Which drug has this MOR?
Reduced permeability in Gram-negative cell membranes
Pseudomonas
15
Narrow spectrum Penicillins
• penicillinase susceptible = Penicillin G (parenteral)
• Penicillin V (oral)
• Used against Streptococci, pneumococci, meningococci (only gram – cocci that responds to penicillin), treponema pallidum
16
how are penicillin V and Penicillin G given?
• Penicillin G = parenteral
• Penicillin V (oral)
17