Oxazolidinones: Mechanism of action and molecular characterization of resistance mechanisms in staphylococci

Oxazolidinones are a new class of antibiotics effective in treating infections caused by various Gram-positive bacteria including methicillin-resistant staphylococci and vancomycin-resistant enterococci. Linezolid, the first oxazolidinone available, has become a valuable clinical option for treating infections due to multidrug-resistant Gram-positive bacteria. It has been used for patients with bacteremia, osteomyelitis, endocarditis, and skin and soft tissue infections, particularly when other therapies failed. Oxazolidinones inhibit the initiation of protein synthesis by specifically binding to the 23S ribosomal ribonucleic acid (23S rRNA) of the 50S subunit of the ribosome. The resistance to other protein synthesis inhibitors does not affect oxazolidinone activity. Rare cases of resistance associated with 23S rRNA alterations during treatment have been reported.