Antibiotics Flashcards
What is the most common mechanism of antibiotic activity
Effects on cell wall integrity
- Interferes with cell wall synthesis
How do beta lactams work
Target serine proteases and penicillin binding proteins
- Inhibits assembly and degrade cell wall
Four different beta lactams
- Penicillin
- Cephalosporin
- Monobactams
- Carbapenems
What is commonly associated with Clostridium difficile infections?
3rd generation/broad spectrum cephalosporins
Penicillin effective against mostly…
Gram +
Cephalosporins mostly effective against…
G- with each generation, but also some G+
Monobactams mostly effective against
Aerobic G-
Carbapenems mostly effective against
G+, G-, anaerobes
Glycopeptides/vancomycin
Targets cell wall
- Targets G+
Lipopeptides/daptomycin
Cell membrane inhibitor
Disruption of ionic concentration gradiet of the cell membrane
- Targets G+
Polypeptides
2 types
Cell membrane target
Bacitracin: topical, G+
Polymyxins/colistin: topical or IV, G-
Antimycobacterial
2 types
Inhibit mycolic acid synthesis in cell wall
Isoniazid and ethambutol
Prokaryotic ribosomes are made up of what?
30s and 50s subunits on the mRNA that lead to translation of genetic message
What are the 3 antibiotics that target the 30s ribosomal subunit
- Aminoglycosides
- Tetracycline
- Glycylcycline
The six antibiotics that target the 50s ribosomal subunit
- Macrolides
- Lincosamide
- Chloramphenicol
- Oxazolidinone
- Streptogramins
- Ketolides
Aminoglycosides
30s
- Almost always used with cell wall synthesis inhibitors
- Anaerobes are usually resistant
- GNR, some GP, mycobacteria
Tetracyclines
30s
- G+, G-, mycoplasma, chlamydiae, rickettsiae
- Not give to <8 yo children, preg women
- Food decreases absorption
Glycylcyclines
30s
- Similar to tetracyclines
- More against G-, anaerobes, rapid growing mycobacteria
Macrolides
50s
- Aerobic and anaerobic G+ cocci
Lincosamides
50s
- G+ cocci, anaerobes
- C. difficile diarrhea