Lecture 14- antibiotics Flashcards
What are these terms:
- naturally made by microorganisms through metabolism, used to inhibit or destroy bacteria
- naturally made, modified in the lab
- drugs made entirely in the lab
- Antibiotic
- Semisynthetic
- Synthetic
What are these terms:
- antibiotics effective against a limited type
- antibiotics effective against a wide range
- used to prevent infection of a person at risk
- Narrow spectrum
- Broad spectrum
- Prophylaxis
What is the antimicrobial process you take to start treatment (4 steps)?
- identify Causative organism
- identify Microorganism susceptibility
- assess Patient condition
- provide antimicrobial treatment
What is the kirby bauer test?
How is it done?
susceptibility test using agar diffusion.
- Antimicrobial discs places on lawn on bacteria
- Measure zone of inhibition
- Compare to chart
How is Kirby bauer test used to test susceptibility?
zone of inhibition greater than chart= Susceptible
less than chart= Resistant
What is an Etest?
How is it done?
Susceptibility test
- Place antibiotic strip with varying concetrations on lawn of bacteria
When is the Etest preferred over Kirby Bauer?
For anaerobic bacteria and determining MIC
- What is the MIC?
- What is the MLC?
- MIC= Minimum inhibitory concentration
lowest amount to prevent growth
- MLC= Minimum lethal concentration
Lowest amount to kill microbe
What is the equation for a therapeutic index?
- Toxic dose
- minimum effective dose
(Smaller ratio=greater chance of toxic drug reaction)
What are the 5 targets of antibiotics?
- Cell wall
- Ribosomes
- Folic acid
- cell membrane
- DNA/RNA
What are the types of antibiotics that target cell wall?
- Beta-lactams
- Glycopeptides
How do Beta-lactams work?
What type of bacteria are they effective against?
- Inhibit Peptidoglycan synthesis.
- Gram-positive bacteria
How do glycopeptides work?
What are they effective against?
- Peptides bind cell wall and prevent new peptidoglycans
- Gram positive cocci
How do Penicillins work?
Use beta lactam ring
How are Cephalosporins work? What do they target?
Given by injection.
Target cell wall
