Antimicrobial agents (Protein inhibitors) Flashcards
Which drugs classes act on the 30S ribosome?
Aminoglycosides, Tetracyclines
Which drug classes act on the 50S ribosome?
Chloramphenicol, Macrolides, Lincosamides, Streptogramins, Oxazolininones
How does resistance to aminoglycosides occur?
1) Modification of drug by phosphorylation, adenylation, or acetylation, 2) Alter drug target (methylation of rRNA/mutation of ribosomal protein, 3)Alter drug exposure (increased efflux)
NOTE: ANAEROBES ARE INTRINSICALLY RESISTANT TO AMINOGLYCOSIDES
Are tetracyclines bacteriostatic or bacteriocidal? And what bacteria do they work on?
bacteriostatic; broad spectrum
How does resistance to tetracyclines occur?
Altered drug exposure (efflux pumps), Altered drug target (ribosome protection proteins)
Is chloramphenicol bacteriostatic or bacteriocidal? And what bacteria does it work on?
bacteriostatic (but bacteriocidal vs. encapsulated organisms); broad spectrum
How does resistance to chloramphenicol occur?
Enzymatticaly inactivates drug via acetyl transferases
Are macrolides bacteriostatic or bacteriocidal? And what bacteria do they work on?
Bacteriostatic; broad spectrum but mainly gram poositive
What are some examples of macrolides?
erythromycin, azithromycin, clarithromycin
Are lincosamides bacteriostatic or bacteriocidal? And what bacteria do they work on?
bacteriostatic; works against gram positive and gram negative ANAEROBES
What is an example of lincosamides?
clindamycin
Are streptogramins bacteriostatic or bacteriocidal?
Individual they are bacteriostatic, together they are bacteriocidal
Are oxazolidinones bacteriostatic or bacteriocidal? And what bacteria do they work on?
bacteriostatic; Works against many gram positive bacteria resistant to other abx
What is an example of a oxazolidinone?
linezolid?
How do resistances to oxazolidinones occur?
Altered drug target (mutations in the 23S rRNA gene)
