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
What do Carbapenems used for?
What do they target?
- Multi-drug resistant bacteria
- Cell wall
What are Bacitracin found in?
What do they target?
Found in Neosporin
Cell Wall
What are Vancomysin used for?
What do they target?
- Treating MRSA
- Cell Wall
How do antibiotics that target ribosomes work?
- Stop peptide bond formation
- Inhibit translation
What are Aminoglycosides used for?
What do they target?
- Bind rRNA to stop translation
- Ribosomes
What type of pathogen are Tetracyclines used for?
What do they target?
- Intracellular Pathogens
- Ribosomes
What do Macrolides have?
What do they target?
- Have Lactose ring.
- Ribosomes
What are Lincosamines good for? Bad for?
What do they target?
- Good for Anarobic bacteria.
- Bad for C. diff overgrowth
- Ribsomes
When are Chlorampehnicol used?
What do they target?
- Only in life threatening cases
- Ribsomes
