Session 4 - Antibiotic and Antimicrobial Stewardship Flashcards
What are the different kinds of antimicrobials?
- Antibacterials
- Antifungals
- Antivirals
- Antiprotozoals
How can antimicrobials be classified?
- Bactericidal (kills pathogen) or Bacteriostatic (stops pathogen from growing)
- On a spectrum of Broad to Narrow in terms of what pathogens it can act on
- Classified via their mechanism of action
- Classified via their chemical structure (antibacterial class)
How do ß-lactams work as an anti-bacteria?
Prohibit cell wall formation:
Binds to the “penicillin binding protein”, which forms cross links in the bacterial cell wall.
This inhibits the protein.
The bacteria therefore cannot reproduce as it cannot produce a cell wall.
Cell wall eventually disintegrates, leaving a vulnerable pathogen.
How do Glycopeptides work as an anti-microbial?
Prohibit cell wall formation:
- Sits on the side chains of the cell wall
- This prevents them from being cross linked by the “penicillin binding protein”
What other mechanisms of action can an anti-bacterial have?
- Prevention of protein synthesis
- Prevention of nucleic acid synthesis
- Prevention of cell membrane function (less common)
What are the types of anti-microbial resistance?
- Intrinsic
- Acquired
- Adaptive
What is intrinsic anti-microbial resistance?
There is no target or access for the drug to act on the microbe.
This is usually permanent.
What is acquired anti-microbial resistance?
The pathogen acquires new genetic material.
This is either through inheritance or plasmids.
This is usually permanent.
What is adaptive anti-microbial resistance?
This happens as a result of the organism responding to stress (an adverse environment), which leads to the bacteria becoming resistant to anti-microbials.
This is usually reversible by lowering the amount of anti-microbial present.
What are the different mechanisms of anti-microbial resistance?
- Drug inactivating enzymes
- Altered target
- Altered uptake
What is the mechanism of resistance for microbials with drug inactivating enzymes?
Microbials develop enzymes that are present on the surface that inactivates the actions of the drugs.
What is the mechanism of resistance for microbials with an altered target?
The target enzyme for the anti-microbial develops a lowered affinity for the anti-microbial.
What is the mechanism of resistance for microbials with an altered uptake?
This is a decreased permeability to the drug from the microbe.
It can also be an increase in the efflux of the drug from the pathogen.
What is anti-microbial stewardship?
A coordinated program that promotes the appropriate use of anti-microbials.
What is ensured by anti-microbial stewardship?
- Optimal clinical outcomes
- A reduction in the costs of healthcare for infections
- Limitation of the selection for antimicrobial resistant strains
