Summary Antibiotics: Cell Wall Inhibitors

Antibiotics: Cell Wall Inhibitors


Cell wall inhibitors: blocks cell wall elongation and division, making wall less rigid
 Peptidoglycan is made up of polymer chains cross linked together by
pentapeptide bridges
  lactam antibiotics inhibit peptidoglycan cross-linking and render the cell
wall weak
  lactams - ‘penicillins’, cephalosporins, carbapenems, monobactams


1) Penicillins- (benzylpenicillin, flucloxacillin, amoxicillin, azlocicillin, piperacillin)
 All act by inhibiting transpeptidase (penicillin binding protein or PBP)
 Prevents cross-linking of peptidoglycan

 lactamase resistance:
 Hydrolyse the lactam ring therefore reducing activity
 Enzyme is secreted by gram positive bacteria (Staphylococcus aureus)
 Lactam antibiotics can induce lactamase enzyme expression
 Clavulanic acid (CA) can be added to lactamase sensitive antibiotics
(e.g. with amoxicillin – co-amoxiclav) and inhibit lactamase enzymes




 Hypersensitivity to penicillin occurs in 1-10% of exposed individuals
(0.05% anaphylaxis)
 Are orally available drugs
 Have a wide range of bioactivity
 Minimal adverse effects