Microbiology Antibiotics

  1. Interferons
    naturally occurring agents produced when cells are infected by virus. IFN-alpha and IFN-beta trigger nonspecific reaction. uninfected cells make antiviral proteins to protect themselves.
  2. spectrum of activity- Interferons
  3. Block attachment/uncoating
    various ones prevent virus by entering host cell
  4. spectrum of activity-block attachment/uncoating
  5. others- block attachment/uncoating
    esample: amatadine prevents uncoating of Influenza A virus
  6. Protease inhibitors
    various ones specific for select protease. inhibits proper formation of "working" proteins
  7. spectrum of activity- protease inhibitors
  8. griseofulvin
    binds to microtubules and prevents spindle apparatus formation
  9. spectrum of activity-griseofulvin
  10. other- griseofulvin
    high penetration into keratin. used for fungal in fects of the skin, nails, ringworm, athletes foot
  11. quinolones/fluoroquinolones
    inhibits DNA gyrase, the enzyme needed for uncoiling bacterial DNA so it can be replicated
  12. spectrum of activity- quinolones/fluoroquinolones
    broad spectrum
  13. other- quinolones/fluoroquinolones
    example: ciprofloxacin (Cipro)
  14. rifampin
    binds to the enzyme RNA polymerase which is needed to synthesize RNA
  15. spectrum of activity-rifampin
    gram positive cocci, tubercle bacilli
  16. nucleoside analogs
    mimic the natural occurring nucleosides. mistakenly incorporated into DNA
  17. spectrum of activity- nucleoside analogs
    DNA viruses
  18. other-nucleoside analogs
    virus must be actively replicating
  19. trimethoprim
    blocks different reaction in folic acid synthesis
  20. spectrum of activity-trimethoprim
    synergistic to sulfonamides
  21. sulfonamides
    competitively inhibits PABA needed for folic acid synthesis so organism cant make nucleic acids
  22. spectrum of activity- sulfonamides
    broad spectrum
  23. antisense nucleic acids
    a strand of nucleic acid complimentary to mRNA, blocks attachment of ribosomal subunits
  24. spectrum of activity-antisense nucleic acids
  25. macrolides
    binds to 50S ribosome which blocks ribosome movement and prevents reading of mRNA
  26. spectrum of activity-macrolides
    gram positive organisms (cant penetrate gram negative cell walls)
  27. other-macrolides
    examples include erythromycin, azithromycin (zithromax) and clarithromycin (biaxin)
  28. tetracyline
    block the docking of the tRNA-AA to the A site of the 30S subunit
  29. spectrum of activity-tetracyline
    gram positive, gram negative, rickettsial and clamydial diseases
  30. other-tetracyline
    discoloration off teeth and stunts bone growth in young children
  31. aminoglycosides
    • blocks reading of mRNA by binding to
    • 30S subunit of ribosome
  32. spectrum of activity-aminoglycosides
    gram negative bacteria and mycobacterium
  33. other-aminoglycosides
    poorly absorbed orally, given IV, narrow therapeutic range, otic and nephrotoxic
  34. chloramphenicol
    prevents peptide bond formation between adjacent amino acids because binds to 50S subunit
  35. spectrum of activity-chloramphenicol
    gram positive and gram negative, rickettsiae, fungi
  36. other-chloramphenicol
    in bone marrow prevents incorporation of hemoglobin into RBS=aplastic anemia
  37. azoles
    change membrane permeability by inhibiting synthesis of ergosterol. blocks the enzyme lanosterol a-demethylase
  38. spectrum of activity-azoles
    effective against fungal cells
  39. amphotericin B
    attaches to ergosterol and changes membrane permeability by creating pores in the membrane
  40. spectrum of activity-amphotericin B
    effective against fungal cells
  41. other-amphotericin B
    high concetrations can target cholesterol in human cells leading to nephrotoxicity
  42. polymixin B
    changes membrane permeability by attaching to phospholipid (phosphatidylethanolamine) in the plasma membrane
  43. spectrum of activity-polymixin B
    gram negative organism especially pseudomonads (pseudomonas aeruginosa)
  44. other-polymixin B
    also targets eukaryotic cells and can use nephrotoxicity used OTC
  45. echinocadins
    inhibit synthesis of b-glucan component of cell wall by inhibiting the enzyme 1,3 b-glucan synthase
  46. spectrum of activity-echinocadins
    effective against fungi (candida and pneumocystis)
  47. isoniazid
    forms a complex within bacteria that blocks the enzyme, fatty acid synthase. this prevents mycolic acid production
  48. spectrum of activity-isoniazid
    acid fast organisms (mycobacterium)
  49. other-isoniazid
    drug of choice however used with other antimicrobial to prevent rapid resistance
  50. vancomycin
    inhibits transport of NAG and NAM to PTG growing points outside of plasma membrane
  51. spectrum of activity-vancomycin
    gram positive organisms (last line against MRSA)
  52. other-vancomycin
    • only used IV
    • known as "Mississippi mud"
    • otic and nephrotoxicity
  53. bacitracin
    inhibits transport of NAM to cell wall by blocking the transporter, bactoprenol
  54. spectrum of activity-bacitracin
    gram positive organisms (staphylococci and streptococci)
  55. other-bacitracin
    renal toxicity restricts use to topical agents (triple antibiotic ointment)
  56. beta-lactams (penicillin/cephalosporins)
    competitively blocks crosslinking of NAG/NAM subunits
  57. spectrum of activity-beta-lactams (penicillin/cephalosporins)
    gram positive (older agents) gram negative (newer agents)
  58. other- beta-lactams (penicillin/cephalosporins)
    beacteria developed lactamases that destroy beta-lactam ring
Card Set
Microbiology Antibiotics
antibiotic notes