Flashcards in Antibiotics Deck (11):
Gram negative vs a gram positive cell envelope
Gram positive have a huge peptidoglycan portion and the gram negative have a small one with an additional outer membrane above that.
How does Vancomycin work and what do we use it on?
This is a giant elephant of a molecule that sterically hinders the assembly of disaccharide subunits, preventing transglycosylation. These guys are very important for the treatment of multi-resistant staph and enterococcus
How do Beta lactam antibiotics work? Big names that fall in this category?
These guys bind transpeptidases to stop cell wall synthesis.
Penicillin, Monobactam, Cephalosporin, and Carbapenem all fall in this group
Inhibits the export of PG components across the cell membrane
Drugs that disrupt cell membranes
polymyxins and daptomycin
Linezolid and what it does to bacteria
This is the only clinically significant drug that inhibits formation of the 70s initiation complex for protein synthesis
It is bacteriostatic for staph and enterococci but it is bactericidal for strep
This guy targets the 30s ribosomal subunit by causing a misread. The 70s subunit still forms but it's wonky and can't make proteins, and in addition, messes with membrane proteins to make them more leaky
How do aminoglycosides work and what do we use them with?
They work very similarly to streptomycin but target 30s and 40s at different proteins.
Great against pseudomonas, but not that effective against most intracellular bacteria
Spectinomycin and what we use it for
This is a bacteriostatic aaminocyclitol antibiotic that also causes the formation of a wonky 70s ribosome but without the misreading.
We use it exclusively for gonorrhea caused by B-lactamase-producing gonococci or to treat gonorrhea in patients allergic to penicillins.
What are tetracyclins and when do we use them?
Bacteriostatic against chlamydia and mycoplasma and ricketts.
Bacterial cells take it up and it targets 30s to inhibit binding of certain a-site tRNAs