What are antibiotics that are only effective against a small number of bacteria?
What are antibiotics that are effective against many bacteria called?
What antibiotic has the widest spectrum of kill?
What's the difference between bactericidal and bacteriostatic?
Bactericidal - kills bacteria, Bacteriostatic - inhibits bacterial growth
Never combine a ___________ antibiotic with a ___________ antibiotic in the same person because?
Bacericidal, Bacteriostatic - because bacteriostatics will inhibit the effects of bactericidal antibiotic
All antibiotics are _________, but not all antibiotics are ___________ at therapeutic doses?
What is minimum inhibitory concentration, and what is it used for?
- Used to determine bactericidal concentration of an antibiotic
- Antibiotics added to test tubes, concentration is the one that kill 100% of the bacteria
Do we give humans antibiotics that reach MIC?
No, it may kill the person - we give less of the antibiotic to get bacteriostatic effect
What is antibiotic synergism?
When 2 antibiotics work together for a more positive effect when given to the same patient
Give an example with antibiotic synergism.
Enterococci infection treated with penicillin and streptomycin to completely kill
What is the predominant microorganism in the oral cavity?
Gram positive strep or staph
What do all oral/facial infection occur from?
Resident microorganisms which are already in the mouth
Why is penicillin always the drug of choice for orofacial infections?
It is the most effective antibiotic against gram postive strep or staph
What is the least toxic antibiotic?
penicillin - cannot kill the host at any concentration
What is penicillin considered to be; bactericidal or bacteriostatic?
What are the 4 ways to minimize resistance?
- Adequate dose
- Adequate duration
- Avoid repeated administration
- Avoid topical administration
How do you choose an antibiotic?
- Identify microorganism
- Determine most effective antibiotic against organism
- Choose an antibiotic with low host toxicity
- Choose a bactericidal antibiotic
- Choose an antibiotic with low resistance potential
Is it safer to give a lower dose to avoid anaphylactic shock?
No - allergic reactions are not dose-dependent
What happens in microbial resistance?
Bacteria resists drug therapy - making drug ineffective
What does nosocomial infection mean?
How do pathogens and tumor cells show microbial resistance?
- Developed mechanisms to inactivate drugs before they bind to targets
- Mutations to prevent the uptake of the drug
- Ability to cause active drug efflux from the cell - pushed drug out of cell
What are sulfa drugs primarily used for?
Urinary tract infections (UTI's)
What was the first antibacterial agent?
What is Trimethoprim?
A sulfa drug used for UTI - brand name = Bactrim