antibiotics 1-2 Flashcards
(44 cards)
“a natural antibacterial substance that is produced by one bacteria that inhibits or kills other bacteria” is this a..
a. antibiotic
b. antimicrobial
a. antibiotic
“any substance that is natural, semisynthetic, or synthetic that kills or inhibits the growth of a microorganism (including bacteria, fungus, protozoa and viruses) but causes little to no damage to the host” is an…
a. antibiotic
b. antimicrobial
b. antimicrobial - these target prokaryotic cells instead of eukaryotic cells, which theoretically means they don’t harm the host)
how are the gazillions of different types of antibiotics classified? hint - 5
- similar chemical structure
- mechanism of action (how they work)
- spectrum of activity (what they work for, eg gram positive or gram negative bacteria)
- bacteriostatic or bactericidal activity
- pharmacokinetic effects (water vs lipid soluble, concentration/time dependent effects)
what are the four main mechanisms of action antimicrobials use to negatively affect bacteria?
- inhibition of cell wall synthesis
- inhibition of nucleic acid synthesis
- disruption of membrane function
- inhibition of protein synthesis
which mechanism of action do the following use: penicillins (beta-lactam grouping), cephalosporins (beta lactam grouping), beta-lactamase inhibitors, carbapenems, bacitracin, glycopeptides
a. inhibition of cell wall synthesis
b. inhibition of nucleic acid synthesis
c. disruption of membrane function
d. inhibition of protein synthesis
a. inhibition of cell wall synthesis (penicillin, anything beta-lactam)
which mechanism of action do polymyxins use?
a. inhibition of cell wall synthesis
b. inhibition of nucleic acid synthesis
c. disruption of cell membrane function
d. inhibition of protein synthesis
c. disruption of cell membrane function
which mechanism of action do the following use: Fluoroquinolones, Nitrofurans, Nitroimidazoles, Sulphonamides?
a. inhibition of cell wall synthesis
b. inhibition of nucleic acid synthesis/function
c. disruption of cell membrane function
d. inhibition of protein synthesis
b. inhibition of nucleic acid synthesis/function
which mechanism of action do the following use: aminoclycosides, tetracyclines, macrolides, lincosamides?
a. inhibition of cell wall synthesis
b. inhibition of nucleic acid synthesis/function
c. disruption of cell membrane function
d. inhibition of protein synthesis
d. inhibition of protein synthesis
if it stains blue/purple, is it…
a. gram negative
b. gram positive
b. gram positive - think blue + positive = toxic masculinity
if it stains pink/red, is it…
a. gram negative
b. gram positive
a. gram negative - misogyny :(
what is the difference between broad spectrum and narrow spectrum antibiotics?
broad spectrum - effective against both gram positive, negative and atypical (don’t stain coloured at all) bacteria
narrow spectrum - either effective against gram positive or gram negative, or an even more specific group under one of those categories
what are the advantages and disadvantages of narrow spectrum antibiotics?
advantages: less likely to disrupt “good bacteria” in the body, reduces risk of antibiotic resistance
disadvantages: needs testing to identify which one you need, no good for a polymicrobial infection (one that involves multiple types of bacteria)
what are the advantages and disadvantages of a broad spectrum antibiotic?
advantages - don’t need to test it’ll be effective against everything, good for when a polymicrobial infection is diagnosed/suspected.
disadvantages - can cause antibiotic resistance and disrupt normal microbiome (which then increases the risk of secondary infections).
are natural penicillins, 1st and 2nd gen cephalosporins, bacitracin, macrolides, lincosamides:
a. gram negative
b. broad spectrum
c. gram positive
c. gram positive (blue!)
are aminoglycosides, 3rd gen cephalosporins, fluoroquinolones, polymixin, nitrofurans:
a. gram negative
b. broad spectrum
c. gram positive
a. gram negative (pink, girlbosses)
are semi synthetic/synthetic penicillins, 4th and 5th gen cephalosporins (and 2nd and 3rd extended spectrum cephalosporins), newer fluoroquinolones, tetracyclines, sulphonamicides and trimethroprim), nitroimidazoles, amphenicols:
a. gram negative
b. broad spectrum
c. gram positive
b. broad spectrum - the synthetic or newer drugs
are nitroimidazoles, lincosamides, penicillins, newer fluroquinolones, tetracyclines (not all)….
a. good at treating anaerobic bacteria
b. bad at treating anaerobic bacteria
a. good at treating anaerobic bacteria
are aminoglycosides, cephalosporins (older/1st and 2nd gen), macrolides, fluoroquinolones….
a. good at treating anaerobic bacteria
b. bad at treating anaerobic bacteria
b. bad at treating anaerobic bacteria
what do bacteriostatic antibiotics do?
a. kill bacteria
b. stop it growing, then the immune system eliminates it instead
b. stop it growing, then the immune system eliminates it instead
what do bactericidal antibiotics do?
a. kill bacteria
b. stop it growing, then the immune system eliminates it instead
a. kill bacteria
lincosamides, macrolides, tetracyclines, sulphonamides, amphenicols… are they:
a. bactericidal
b. bacteriostatic
b. bacteriostatic
penicillins, cephalosporins, nitroimidazoles, aminoglycocides, fluroquinolones, polymixins… are they:
a. bactericidal
b. bacteriostatic
a. bactericidal
what are three situations where bacteriostatic drugs are sufficient or advantageous?
- Common infections in patients with a healthy immune system. The inhibited bacteria are cleared by the host’s immune defenses.
- Better suited in some infections (e.g., bacterial meningitis, severe sepsis or septic shock) where rapid killing of bacteria can lead to a sudden release of bacterial toxins, potentially worsening the inflammatory or shock response.
- Less disruptive effects on the normal gut microbiota. Maintaining a healthy microbiome is increasingly recognised as important for overall health.
what are four situations where bactericidal drugs may be preferred:
- In severe life-threatening infections rapid and complete eradication of bacteria is important to quickly reduce the bacterial load.
- In immunocompromised patients as they may not be able to clear infections after bacterial growth is inhibited by bacteriostatic drugs.
- To clear infections when the immune response cannot easily penetrate the site of infection (e.g., abscesses, biofilms, some deep-seated tissue infections).
- In seriously ill patients when treatment needs to be started before the causative organism is identified (empirical antibiotic therapy).
