antibiotics Flashcards
(19 cards)
What are antibiotics derived from?
Micro-organisms
Antibiotics are natural substances produced by microorganisms that inhibit the growth of other microbes.
What are chemotherapeutic agents?
Synthetically derived
These agents are chemically manufactured to treat infections.
What is meant by selective toxicity in antimicrobials?
Effective in treatment by exploiting biochemical differences
Selective toxicity allows for the targeting of pathogens without harming host cells.
What are the primary sites of action for antibacterials?
- Cell wall
- DNA synthesis
- Protein synthesis
These sites are crucial for the mechanism of action of various antibacterial agents.
Name three classes of antibiotics that target protein synthesis.
- Macrolides
- Tetracyclines
- Aminoglycosides
These antibiotics interfere with bacterial protein synthesis, affecting bacterial growth and replication.
What are the two classifications of antibiotics based on their spectrum?
- Narrow spectrum
- Broad spectrum
Narrow spectrum antibiotics affect only a few types of bacteria, while broad spectrum antibiotics can target a wide range.
What does antimicrobial resistance mean?
Bacterial growth is unaffected by antibacterial agent
Resistance can occur due to various mechanisms that allow bacteria to survive despite the presence of antibiotics.
List one mechanism of antimicrobial resistance.
- Change in permeability of cell wall
- Change in target site
- Efflux
- Change in metabolic pathways
- Degradation by enzymes
These mechanisms help bacteria evade the effects of antibiotics.
What is the Minimum Inhibitory Concentration (MIC)?
Lowest drug concentration that inhibits bacterial growth
MIC is a crucial measure in determining the effectiveness of an antimicrobial agent.
What is the Minimum Bactericidal Concentration (MBC)?
Lowest drug concentration that results in a 99.9% decline in bacterial colony count
MBC is used to evaluate the bactericidal activity of an antibiotic.
What is the advantage of using combinations of antibiotics?
Synergism: combination is more effective
Combining antibiotics can enhance their effectiveness against infections.
What is a disadvantage of combination antibiotic therapy?
Act only when organisms are multiplying
This can limit the effectiveness of certain antibiotics when used together.
What are the four generations of cephalosporins?
First, second, third, fourth
Each generation has different properties and spectrum of activity against bacteria.
What is a notable characteristic of fluoroquinolones?
Broad spectrum and bactericidal
Fluoroquinolones are effective against a wide range of bacteria and kill them.
What is the classification of penicillins?
Beta-lactams
Penicillins are one of the oldest classes of antibiotics and are bactericidal.
Fill in the blank: Tetracyclines are _______.
Bacteriostatic
Tetracyclines inhibit bacterial growth without killing them directly.
What is a risk associated with aminoglycosides?
Irreversible ototoxicity
Aminoglycosides can cause permanent damage to hearing.
What class of antibiotics should be avoided in pregnancy due to potential harm?
Tetracyclines
Tetracyclines can affect bone growth and teeth development in fetuses.
True or False: Macrolides are bactericidal antibiotics.
False
Macrolides are classified as bacteriostatic antibiotics.
