Expansion
Cell wall, protein synthesis, nucleic acid and folate synthesis
Expansion
Cell wall synthesis
- Beta-lactams: penicillins, cephalosporins, carbapenems, monobactams. Inhibit penicillin-binding proteins (transpeptidases)
- Glycopeptides: vancomycin, teicoplanin. Bind D-alanyl-D-alanine
Protein synthesis (Buy AT 30, CELL at 50)
- 30S: Aminoglycosides, Tetracyclines
- 50S: Chloramphenicol, Erythromycin and macrolides, Lincosamides (clindamycin), Linezolid
Nucleic acid
- Fluoroquinolones: DNA gyrase (topoisomerase II) and topoisomerase IV
- Rifampicin: bacterial RNA polymerase
- Metronidazole: free radical damage to DNA in anaerobes
Folate synthesis
- Sulphonamides: dihydropteroate synthase
- Trimethoprim: bacterial dihydrofolate reductase. Combined as co-trimoxazole for sequential blockade
Bactericidal classes: beta-lactams, aminoglycosides, quinolones, metronidazole, vancomycin, rifampicin. Bacteriostatic: tetracyclines, macrolides, clindamycin, trimethoprim, chloramphenicol. The distinction matters most in endocarditis, meningitis and neutropenia, where a bactericidal agent is preferred.