Linezolid is a synthetic, antibacterial agent belonging to a new class of antibiotics, the oxazolidinones, with in vitro activity against Gram positive aerobic bacteria, some Gram positive anaerobic bacteria and certain Gram negative bacteria. It selectively inhibits bacterial protein synthesis via a mechanism of action different from that of other antibacterial agents. Linezolid binds to the 23S ribosomal RNA of the 50S subunit of the bacterial ribosome and prevents the formation of a functional 70S initiation complex which is an essential component of the bacterial translation process. The results of time-kill studies have shown Linezolid to be bacteriostatic against enterococci and staphylococci. For streptococci, Linezolid was found to be bactericidal for the majority of strains.