anti-biotics: Protein Synthesis Inhibitors Flashcards
protein synthesis inhibitors act on what ribosome subunits?
30s and 50s
what are the protein synth. inhibitors?
(AT CELLS)
Aminoglycosides
Tetracyclines
Chloramphenicol
Erythromycin (Macrolide)
Linezolid
Lincosamide (Clindamycin)
Streptogramins
what are the protein synthesis inhibitor drugs that act on the 30s ribosomal subunit?
aminoglycosides
tetracyclines
what are the protein synthesis inhibitor drugs that act on the 50s subunit?
Chloramphenicol
Erythromycin (Macrolide)
Linezolid
Lincosamide (Clindamycin)
Streptogramins
aminoglycosides will kill bacteria as long as they are what?
aerobic bacteria or gram negative bacteria, it does nothing to anaerobic
what are the aminoglycoside drugs?
Gentamicin
Neomycin
Amikacin
Tobramycin
Streptomycin
Kanamycin
Netilmicin
how do aminoglycosides work?
they will bind to the 30s ribosomal subunit and inhibit bacterial protein synthesis
it will inhibit the initiation complex which induces misreading of mRNA
how are aminoglycosides administered?
can it be orally?
parentally (intramuscularly and intravenous)
not orally, barely absorbed
how can bacterial resistance be acquired to aminoglycoside drugs?
bacterial transferase enzymes inactivate the drug by:
phosphorylation, adenylation, and acetylation
Essentially resistance is acquired by altering the structure of the antibiotic
all protein synthesis inhibitors have good activity towards what bacteria?
gram negative aerobic bacilli
why do aminoglycosides need O2 to take effect in the 30s ribosome of bacteria?
because O2 is needed for transport across the inner membrane of bacteria (therefore, bacteria must be aerobes)
what bacteria are resistant to aminoglycosides?
anaerobic bacteria and gram + bacteria
why cant gram + bacteria be targeted only with aminoglycosides?
what is the work around?
because the cell wall is too thick
this is why aminoglycosides are used with ß-lactam or vancomycin drug (cell wall synthesis inhibitor)
streptomycin is used against what bacteria?
tuberculosis
what activity do tetracyclines have?
bacteriostatic activity
how do tetracyclines work?
they will bind to the 30s subunit blocking +RNA from entering the acceptor site
What are the tetracyclines?
tetracycline
doxycycline
minocycline
demeclocycline
how do tetracyclines work?
(STOPS PROTEIN SYNTH.)
- it prevents addition of amino acids to growing peptides
- blocks aminoacyl t-RNA from binding to mRNA-30s ribosome complex*
what will demeclocyclin affect in the body?
it will make renal tubules resistant to ADH action