Since the discovery of antibiotics in the 1920s, the treatment of bacterial infections in humans and animals has emerged as a revolutionary possibility. Antibiotics are drugs naturally produced by bacteria or fungi to defend against other bacteria via death or by inhibiting reproduction (1). Since their detection, antibiotics have been diversified into many different forms and classes, classified by mode of action. Glycopeptides are a class of antibiotics composed of glycolsylated, cyclic or polycyclic nonribosomal peptides that inhibit cell wall synthesis in susceptible bacteria (2). However, it was soon discovered that the use of these antibiotics could lead to antibiotic resistance. This article will discuss the history, function, and resistance associated with vancomycin, a glycopeptide antibiotic. HistoryVancomycin, which is a specific antibiotic belonging to the glycopeptide antibiotic subset, was first discovered in a soil sample in the jungle of Bornea by Dr. EC Kornfield. during an antimicrobial research program in 1953 (2). Vancomycin is a bactericide collected from a strain of bacteria known as Streptomyces orientalis and, during its initial mass production in the 1950s, it was found to contain many impurities which may have led to its early ototoxic and nephrotoxic properties, making it a secondary drug upon initial approval. by the FDA (3). However, it has since been further purified and these properties have dissipated, leaving a very pure and low-toxic antimicrobial agent. It is now used as a last resort antibiotic and is mainly administered intravenously; however, studies are underway to interpret the best way to administer the drug as new vancomycin-resistant species are revisited. Mol Microbiol2003;50:931-48(18) Courvalin, Patrice. (2006). Vancomycin resistance in Gram-positive cocci. Clinical Infectious Diseases, 42 (Supplement 1), S25-S34. doi: 10.1086/491711(19) Arthur M, Reynolds P, Courvalin P Glycopeptide resistance in enterococci.TrendsMicrobiol 1996;4:401-7.(20) Arthur M, Depardieu F, Cabanie L, Reynolds P, Courvalin P. Requirement of the D,D-peptidases VanY and VanX for glycopeptide resistance in enterococci. MolMicrobiol 1998; 30: 819-30 (21) Reynolds PE, Courvalin P. Vancomycin resistance by synthesis of precursors ending in D-alanyl-D-alanine. Antimicrobial agents Chemother 2005; 49:21-5. (22) Depardieu F, Reynolds PE, Courvalin P. Enterococcus faecium 10/96A resistant to vancomycin type VanD. Chimother Antimicrobial Agents 2003;47:7-18.