Lincosamides, Oxazolidinones, and Streptogramins

Lincosamides (clindamycin Clindamycin Clindamycin is a lincosamide antibiotic that is primarily bacteriostatic. It binds to the 50S subunit of the ribosome, thus inhibiting bacterial protein synthesis. Clindamycin is absorbed well... read more ), oxazolidinones (linezolid, tedizolid Linezolid and Tedizolid Linezolid and tedizolid are oxazolidinone antibiotics. Linezolid is an oxazolidinone antibiotic that has activity against the following: Streptococci Enterococci, including vancomycin-resistant... read more ), and streptogramins (dalfopristin [streptogramin A] and quinupristin [streptogramin B Quinupristin and Dalfopristin Quinupristin and dalfopristin are streptogramin antibiotics, which, like macrolides and lincosamides, inhibit the synthesis of bacterial proteins. Quinupristin/dalfopristin (Q/D) is given together... read more ]) are structurally different but are grouped together because they have a similar mode of antibacterial action and similar antibacterial spectra. Macrolides Macrolides Macrolides are antibiotics that are primarily bacteriostatic; by binding to the 50S subunit of the ribosome, they inhibit bacterial protein synthesis. Macrolides are relatively poorly absorbed... read more (except for fidaxomicin) and chloramphenicol Chloramphenicol Chloramphenicol is an antibiotic that is primarily bacteriostatic. It binds to the 50S subunit of the ribosome, thereby inhibiting bacterial protein synthesis. Chloramphenicol is well absorbed... read more may be included with this group for similar reasons. All inhibit protein synthesis by binding to the 50S ribosomal subunit. Fidaxomicin has a completely different mode of action than other macrolides; it inhibits RNA polymerase by binding to the DNA template–RNA polymerase complex.

Certain methyl-transferase enzymes can mediate resistance to multiple members of the above classes. The erythromycin resistance methylase (erm) gene commonly mediates resistance to macrolides, clindamycin, and quinupristin but not the oxazolidinones or dalfopristin. The chloramphenicol-florfenicol resistance (cfr) gene mediates resistance to chloramphenicol, dalfopristin, clindamycin, and oxazolidinones, but tedizolid may retain susceptibility in some strains. Certain multidrug efflux pumps can also produce cross-resistance between some of these classes as well.