Antimicrobial agents Flashcards
What is Rifampin selective
There is a difference between mammalian and bacterial rna polymerase
what part of the mammalian cell does rifampin effect?
the mt because these have more bacterial transcription systems
what is rifampin used with??
other antibiotics
how is rifampin made?
from soil bacteria
where does rifampin bind?
to a pocket in the beta subunit of rna polymerase in the channel where the DNA is kept this blocks elongation
whart does erythromycin bind to?
the 50s subunits of the ribosome
what is erythromycin made of?
12016 carbon ring
what part of translation does erythromycin block?
translocation
where is erythromycin more effective?
the gram positives
what is a tetracyclin a type of?
macrolide
what does tetracyclin bind to?
the 30s subunit of the ribosome
what does tetracycllin stop?
the binding of the aa tRNA to the ribosome acceptor site
why is tetracyclin not selective but still ok?
it doesnt build up in high enough conc in euk cells to damage euk ribosomes
what type of molecule is kanamycin?
an aminoglycoside
what does kanamycin target?
the 30s subunit of the ribosome
what does kanamycin cause?
the misreading the mRNA because it is misaligned
what is kanamycin produced by?
streptomyces
what does gyrase use to form negative superocils in DNA?
atp
what is an ezmple of a gyrae inhibitor?
ciproflaxin
what structue is ciproflaxin
two hegagons called the quinolone ring with a F attached
what does the ciproflaxin do?
binds to the DNA gyrase comples so that the GYrase cannot unbind
what does ciproflaxin lead to
the stress response which is the fragmentation of the chromosome and cell death
why isnt ciproflaxin selective and why si this ok?
because it can still harm euk topos but the therapuetin concnetration is not toxic to our own cells
what structure are the polymycxins?
tere are cation cyclicpeptides
what kind of molcule is a polymyxin?
an antibiotic
whar is polymyxin used for ?
MDR last resort
how does poly work
binds to the oppositelt charged LPS which diables it which destoys the outmemberane causing leakage and cell death
what does isoniaazid do how is it digested?
it is activated by the TB enzymes and dsirupts the mycolic acid wall
what is used ot treat TB?
directly observed treatment short coaure combination therapy
