1. What is the MOA of beta-lactams?
    inhibition of peptidoglycan and cell wall synthesis
  2. What is the mechanism of resistance to beta-lactams?
    • 1. beta lactamase enzymes
    • 2. decreased penetration (porin changes)
    • 3. alteration in penicillin-binding proteins
  3. How is methicillin resistance from beta lactase acquired?
    -by the insertion of a horizontally transferred DNA element called SCCmec

    -The mega gene encodes PBP2a (a beta-lactam insensitive PBP) which continually synthesizes new cell wall peptidoglycan, even when usual PBP's are inhibited.
  4. What is the only effective beta-lactam antibiotic against MRSA?
  5. What are beta lactase inhibitors?
    "suicide" inhibitors that bind to and inactivate beta-lactase enzymes
  6. What are ESBLs?
    ESBL's are extended spectrum beta-lactamases that are plasmid-mediated enzymes that inactivate a wide range of beta-lactams, and also confer resistance to many other antimicrobials 

    ex. of resistance = quinilones, tetracyclines, TMP/SMX
  7. Name primary examples of of beta-lactamase inhibitors.
    • -clavulanic acid
    • -sulbactam
    • -tazobactam
    • -avibactam
  8. Describe the absorption profile of beta-lactams.
    • -variable PO (oral) absorption
    • -generally should be taken 1 hour before or 2 hours after meals
  9. Describe the distribution profile of beta-lactams.
    • -wide distribution to tissues and fluids
    • -variable CNS penetration; 3rd generation cephalosporins are widely used in meningitis
  10. Describe the metabolism and excretion profile of beta-lactams.
    • -primarily eliminated really
    • -nafcillin, oxacillin, and ceftriaxone are eliminated hepatic ally
    • -most have very short half lives
  11. Name the "natural penicillins".
    Penicillin G and Penicillin VK
  12. What organisms are Penicillin G and Penicillin K active against?
    Streptococcus spp., Neisseria miningitis, Pasturella multocida, Treponema pallidum, Listeria monocytogenes

    NO ACTIVITY against staphylococcus app. and most gram negs
  13. Are penicillin G and VK effective against anaerobes?
    Yes. Above the diaphragm
  14. What is penicillin G and VK the drug of choice for?
    infections caused by Group A Strep (progenies) and Treponema palladium (syphilis)
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