Antimicrobials: Cell Wall Inhibitors Flashcards
Beta lactam inhibitors include what types of abx
- penicillin
- cephalosporins
- carbapenems
- monobactams
Active site for beta lactams is
Beta lactam ring
Two major beta lactam ring subclasses
- 5 member rings (thiazolidine)
- 6 member rings (dihydrothiazine)
Example of abx in the thiazolidine ring subclass
Penicillins
Example of abx in dihydrothiazine ring subclass
Cephalosporins
How are beta lactam rings broken down?
- Beta lactamase (prod. by staph & gram -ve bacteria)
Beta-lactamase inhibitors
- clavulanate aid, tazobactam, & sulbactam
MOA of beta lactams
- target transpeptidase enzymes
- autolysins contribute instability
- cell wall becomes permeable -> osmotic lysis -> cell death
Beta lactams bind to…
Transpeptidase active site
Model penicillin drugs (4)
- penicillin
- amoxicillin
- amoxicillin + clavulanic acid
- ampicillin
Types of penicillin subclasses
- natural (1st tier)
- semi-synthetic aminopencillins (1st tier)
- anti staphyloccal penicillin
- carbapenems (3rd to 4th tier)
What microbes are natural penicillin resistant?
- pseudomonas
- most enterobacteriaceae
- penicillinase producing staphylococcus spp.
2 types of natural penicillins and their method of admin.
- penicillin G (IM/SQ)
- penicillin V (oral)
Natural penicillins are effective against which microbes?
- Gram positive Streptococcus
- anaerobes: Pasteurella, arcanobacterium (actinomyces), listeria monocytogenes, leptspira, borrelia
Which penicillin is acid-labile
Penicillin G
Semi-synth. Aminopenicillins include
Ampicillin & amoxicillin (+/- clavulanic acid)
Semi-synthetic aminopenicillins are inactive against…
- pseudomonas
- bacteriodes fragilis
- penicillinase producing staph.
Semi-syntheic aminopenicillins are effective against…
- gram +ve
- anaerobes
- gram -ve: E.coli, Klebsiella, Proteus
Clavamox is used to Tx what in small animals?
- infections in almost all tissues (not CNS)
Anti-staphylococcal penicillins include…
- drugs ending in “-cillin”
- ex: methicillin, nafcillin, oxacillin, cloxacillin, and dicloxacillin
Anti-staphylococcal penicillins active against…
Penicillinase producing staphylococcus spp.
Anti staphylococcal penicillin vet med uses
- rarely used in vet med
- only used in MRSA or MRSP (methicillin-resistant staphylococcus pseudointermedius) infections
