Chapter 16 Antimicrobials (diana's version) Flashcards
how does antimicrobial drugs acts?
usually act by interfering with the growth of microorganisms
Unlike disinfectants these must work inside of the patient and therefore should exhibit selective toxicity
antimicrobial drugs
what is selective toxicity again?
damage the pathogen without harming the host
Antimicrobial rugs:
spectrum of antimicrobial, what are the two options?
Spectrum of antimicrobial activity:
1.narrow spectrum
2.broad spectrum
what is a narrow spectrum
the drug is only effective against a limited range of microorganisms
set an example, of narrow sepctrum
penicillin G affects mainly gram positive bacteria
what is a broad spectrum drug
the drug affects a wide range of organisms
what is the advantage of broad spectrum and what is the disadvantage?
advantage: these drugs are useful when the identity of the organism is unknown
disadvantage: these drugs are bad for normal microflora
set an example for broad sepctrum
tetracycline affects both gram positive and gram negative
this is targetting one specific thing and not anything else
narrow
less bacteria being harmed, lessen the risk of opportunistic pathogen, is this true?
true
vitamin k is important for??
blood clotting
antibacterial agents:
if the drug kills bacteria it is reffered to as what?
bacteriocidal
antimicrobial agents:
if the drug inhibits the growth of bacteria it is referred to as
bacteriostatic
cell wall active agents:
inhibition of cell wall synthesis:
target peptidoglycan synthesis
without peptidoglycan bacteria that try to grow will lyse
only works on organisms that are actively growing
peptidoglycan is only found in bacteria
excellent selective toxicity
these are most frequently used class of antimicrobial drugs
cell wall active agents go after what ?
they go after cell wall and target peptidoglycan
you are putting something foreign particle inside of your body, however it is an excellent selective toxicity, not going after you
cell wall synthesis
you want them to burst , no where in your body that are harming, the outcome is not harming your tissues
cell wall synthesis
cell wall active agents
Penicillins and Cephalosporins :
Group of 50 antibiotics
penicillins are naturally found antibiotics
all contain a core chemical structure : beta-lactam ring
prevent peptidoglycan cross linking
penicillin G, amoxicillin, ampicillin, methcillin
this is semi synthetic - a little bit fake
even bug makes the b lactamase the drug is resistant to b lactamese activity- the outcome is that drug will still work
cell wall active agents
what does prevent peptidoglycan cross linking
NAM-NAG-NAM-NAG-NAM
it’s not made in chemistry lab, made from bacteria microbial antagonism
cell wall active agents
the bug can have a gene to make B lactase enzyme - he can breaks it open
B lactam
is penincillin a broad beta lactamase? or narrow
broad lactamase