Comycetin inhibits bacterial protein synthesis by binding to 50s subunit of the bacterial ribosome, thus preventing peptide bond formation by peptidyl transferase. It has both bacteriostatic and bactericidal action against H. influenzae, N. meningitidis and S. pneumoniae. Comycetin is a broad-spectrum antibiotic that was derived from the bacterium Streptomyces venezuelae and is now produced synthetically. Comycetin is effective against a wide variety of microorganisms, but due to serious side-effects (e.g., damage to the bone marrow, including aplastic anemia) in humans, it is usually reserved for the treatment of serious and life-threatening infections (e.g., typhoid fever). Comycetin is bacteriostatic but may be bactericidal in high concentrations or when used against highly susceptible organisms. Comycetin stops bacterial growth by binding to the bacterial ribosome (blocking peptidyl transferase) and inhibiting protein synthesis.
