Microbiology Antimicrobial Chemotherapy Test Three

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Microbiology Antimicrobial Chemotherapy Test Three
2011-05-01 02:09:06
Microbiology Antimicrobial Chemotherapy Test Three

Microbiology Antimicrobial Chemotherapy Test Three
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  1. What are the two main ways antibiotics work?
    • Cell wall synthesis inhibition
    • Protein synthesis inhibition
  2. The antibiotic __?__ interferes with our ribosomes.
  3. Ideal antibiotic should affect __?__.
    Microbial physiology
  4. Antibiotic compounds are classified by __?__ and __?__.
    • Spectrum of activity
    • Type
  5. The two spectrums of activity are __?__ and __?__.
    • Broad: effective against many species
    • Narrow: effective against few species
  6. The two types of antibiotics are __?__.
    • Bacteriocidal: kill target organism
    • Bacteriostatic: prevent growth of organism
  7. Bacteriocidal drugs typically only work on __?__ cells by __?__. An example of a bacteriocidal drug is __?__.
    • growing
    • inhibiting cell wall synthesis
    • Penicillin + derivatives
  8. How do bacteriostatic drugs aid in fighting infection?
    Slowing down growth so the immune system can eliminate it.
  9. Minimal inhibitory concentration is __?__. MLC is __?__.
    • MIC: the lowest concentration of a drug needed that prevents growth
    • MLC: minimum lethal concentration - sterile
  10. Multiple drug coated disks put on a culture plate tests for __?__ and is known as __?__.
    • drug susceptibility
    • Kirby-Bauer
  11. __?__ are the five mechanisms of antibiotic action.
    • Inhibit nucleic acid synthesis
    • Inhibit folate synthesis
    • Depolarization of membrane
    • Inhibit protein synthesis
    • Inhibit cell wall synthesis
  12. Penicillin and Cephalosporin are antibiotics that work through what mechanism?
    Inhibit cell wall synthesis by acting a competitive inhibitor of transpeptidase. Beta lactam ring
  13. __?__ is the structure of the beta lactam ring.
  14. Ampicilin and amoxicillin are derivatives of __?__ and are resistant to __?__.
    • Penicillin
    • Acid hydrolysis (why they can be taken orally)
  15. Amp and amo are __?__ spectrum and work on __?__ bacteria.
    • Broad
    • G (-)
  16. Oxacillin, dicloxacillin, and methicillin are resistant to __?__ because of __?__ but are not effective against __?__ bacteria.
    • Beta-lactamases
    • bulky side chain (always determines characteristics of cell wall inhibitors aka penicillin and derivatives)
    • G (-)
  17. What are the mechanisms of protein inhibtion synthesis? (3)
    • Block transf of peptides by binding large ribosomal subunit - (Macrolides, chloramphenicols, lincosamides)(Erythromycin, azithromycin)
    • Prevent 30 and 50s subunits from binding eachother - (Aminoglycosides)(Streptomycin)
    • Bind small subunit and block aminoacyl-tRNA (Tetracyclines)
  18. __?__ are the four bacterial resistance mechanisms and their mechanisms?
    • Destroy antibiotic Beta lactamase
    • Modifiying the antibiotic Acetylation, adenylation, phosphorylation via cellular enzymes
    • Altering the Target Changing target site for antibiotic on target enzyme Most common in streptomycin resistance
    • Eflux Removes drug from cell
  19. __?__ are the two ways bacteria aquire resistance to antibiotics.
    • Mutation (alteration of target site) occurs naturally and is selected for
    • Horizontal gene transfer