Question | Answer |
What are the principle bacterial targets for antimicrobials? | 1) Cell wall peptidoglycan 2) Machinery of protein synthesis 3) Outer cell membrane 4) Enzymes of bacterial nucleic acid metabolism 5) Enzymes involved in folic acid symtheiss |
What are some drugs that act on cell wall peptidoglycan? | fosfomycin, bacitracin, vancomycin, penicillin and other B-lactams |
What are some drugs that act on the ribosome and other aspects of protein synthesis? | erythromycin, clindamycin, tetracycline, gentamicin, kanamycin, streptomycin, spectinomycin |
What are some drugs act on the 30S ribosome? | clindamycin, erythromycin |
What are some drugs act on the 50S ribosome? | tetracycline, aminoglycosides |
What are some drugs act on RNA synthesis? | rifampin, rifabutin |
What are some drugs act on DNA replication? | metronidazole, ciprofloxacin and other fluorquinolones |
What are some drugs act on folic acid synthesis? | sulfonamides, trimethoprim |
What are some drugs that act on the cell membrane? | polymixin B, colistin |
What are the four major mechanisms for antimicrobial resistance? | 1) Change in the drug target 2) Production of an enzyme that modifies or inactivates the agent 3) Reduced accumulation of the agent 4) Loss of a pathway involved in drug activation |
Why is optimal usage of antimicrobial so important? | Usage selects for resistance |
What are some examples of in vitro susceptibility tests? | broth dilution, disc diffusion |
Which is more important, MIC-50 or MIC-90? | MIC-90 is more useful than the MIC-50 value in the initial selection of an antibiotic |
What is the most significant mechanism of resistance to penicillin? | Ability of B-lactamases to hydrolyse the B-lactam ring |