Antibiotics 1 - Beta-Lactam/Penicillin Cell Wall Inhibitors Flashcards
Fosfomycin
blocks cell wall SYNTHESIS (by blocking NAM synthesis from NAG).
Cycloserine
blocks cell wall SYNTHESIS (by incorporating instead pf D-ala-D-ala on NAM).
Vancomycin
blocks cell wall SYNTHESIS (binds and blocks D-ala-D-ala, blocks lengthening by Transglycosylase).
Bacitracin
blocks cell wall ASSEMBLY (by blocking lipid carrier); only used as topical ointment.
What are beta-lactams?
block cell wall CROSS-LINKING by Transpeptidase.
4 major classes of beta-lactams?
Penicillins, Cephalosorins, Monobactams, Carbapenems.
how do antibiotics get across outer membrane of Gram negative bacteria?
can get through Porin channels if small and hydroPhilic.
how do bacteria become resistant to beta-lactams?
either (1) change binding site on transpeptidase, or (2) produce beta-lactamase to cleave the drug.
4 diff types of Penicillins?
Narrow spectrum (for Gram Pos),
Extended spectrum,
Antistaph,
& Antipseudomonal.
Penicillin G and V?
Penicillin G = “G IVe by IV” (gold standard).
Penicillin V = “tongue, give orally”.
+ are for narrow spectrum (Gram Pos).
Penicillin mixed with a local anesthetic like procaine?
“repository penicillin”, GIVEN IM in muscle, for slow-release.
Ampicillin and Amoxicillin?
“AMPed up Penicillins = Extended spectrum”;
Amoxicillin is given Orally, (AmpIcillin is given IV).
Nafcillin, Oxacillin, Dicloxacillin
“for anti-Staph use Naf!”; (“Naf, Oxa, Dicloxa”)
the “methicillin” antibiotics to kill Staph.
MRSA?
“Methicillin Resistant Staph Aureus”;
can’t be killed by Methicillin, Naf, Oxa, Dicloxa Anti-staph Penicillins.
Test Staph to see if MRSA or MSSA (Methicillin-sensitive)?
MRSA will turn pink on Chromogenic Agar;
“evil pink MRSA”
