Class |
Mechanism of Action |
Mechanism of Resistance |
Resistant Bacteria |
Aminoglycosides |
Bactericidal; Inhibition of 16S ribosomal subunit |
Target site mutation |
Mycobacterium tuberculosis |
Enzymatic alteration of target |
Actinomycetes |
Chemical alteration of antibiotic |
Salmonella enterica, Klebsiella pneumoniae, Legionella pneumophila |
Beta-lactams |
Bactericidal; Inhibition of penicillin binding protein (PBP) preventing peptidoglycan cross-linking |
Complete replacement/bypass of target site |
Staphylococcus |
Destruction of antibiotic |
Escherichia coli |
Decreased permeability |
Escherichia coli |
Epoxides |
Bactericidal; Inhibition of UDP-N-acetylglucosamine-3- enolpyruvyltransferase (MurA) |
Destruction of antibiotic |
Escherichia coli, Pseudomonas aeruginosa, Streptococcus |
Glycopeptides |
Bactericidal; Inhibition of peptidoglycan synthesis |
Target site mutation |
Staphylococcus, Streptococcus, Enterococcus |
Global cell adaptations |
Staphylococcus |
Lipopeptides |
Bactericidal; Disruption of the cellular membrane permeability and depolarization |
Global cell adaptations |
Staphylococcus, Enterococcus |
Lincosamides |
Bacteriostatic; Inhibition of 23S ribosomal subunit |
Target protection |
Staphylococcus |
Target site mutation |
Mycobacterium avium, Helicobacter pylori, Streptococcus pneumoniae |
Enzymatic alteration of target |
Staphylococcus, Enterococcus, Bacteroides |
Macrolides |
Bacteriostatic; Inhibition of 50S ribosomal subunit |
Target protection |
Staphylococcus |
Target site mutation |
Mycobacterium avium, Helicobacter pylori, Streptococcus pneumoniae |
Enzymatic alteration of target |
Staphylococcus, Enterococcus, Bacteroides |
Destruction of antibiotic |
Staphylococcus, Enterococcus |
Efflux pumps |
Staphylococcus, some Gram-negative species |
Oxazolidinones |
Bacteriostatic; Prevents initiation complex formation by binding the 23S portion of the 50S ribosomal subunit in such a way that the 30S subunit is blocked from adjoining |
Target protection |
Streptococcus |
Target site mutation |
Staphylococcus, Streptococcus, Enterococcus |
Enzymatic alteration of target |
Staphylococcus, Streptococcus |
Pleuromutilins |
Bacteriostatic; Inhibition of 50S ribosomal subunit |
Target protection |
Staphylococcus, Streptococcus, Enterococcus |
Enzymatic alteration of target |
Staphylococcus, Enterococcus |
Quinolones |
Bactericidal; Inhibition of DNA synthesis through binding DNA topoisomerase IV and DNA gyrase |
Target site mutation |
Staphylococcus, Enterococcus |
Target protection |
Mycobacterium, Enterococcus, Pseudomonas |
Rifampin |
Bactericidal; Inhibition of DNAdependent RNA polymerase (RNAP) |
Target site mutation |
Mycobacterium tuberculosis |
Streptogramins |
Bacteriostatic; Inhibition of 50S ribosomal subunit |
Target protection |
Staphylococcus, Streptococcus, Enterococcus |
Enzymatic alteration of target |
Staphylococcus, Streptococcus, Enterococcus |
Sulfonamides |
Bacteriostatic (bactericidal when combined with trimethoprim); Inhibition of dihydropteroate synthase (DHPS) (SMX) and dihydrofolate reductase (DHFR) (TMP) |
Complete replacement/bypass of target site |
Staphylococcus, Escherichia coli |
Tetracyclines |
Bacteriostatic; Inhibition of 30S ribosomal subunit |
Target protection |
Campylobacter, Staphylococcus, Streptococcus, Enterococcus |
Efflux pumps |
Staphylococcus, Streptococcus, Enterococcus, Enterobacter |