The vancomycin resistance was initially identified to be conferred by an operon of eight genes (Figure 1). Vancomycin resistance is known to be transferable [2] and many transferable resistance mechanisms are the result of single genes; vancomycin resistance thus showed a quantum leap in the sophistication of resistance determinants. The original operon was bound by insertion sequences encoding transposon Tn1546 [3]. The two genes of a classic class II transposon ensure the migration of the gene between replicons and different strains. Three essential genes (vanH, vanA and vanX) are responsible for initiating an alternative route to peptidoglycan synthesis that removes the glycopeptide binding site of the d-alanyl-d-alanine group on the pentapeptide. This alternative route involves reversing the formation of the d-alanyl-d-alanine moiety (VanX) to release free d-alanine, hydrogenating pyruvate to form lactate (VanH), which is then ligated with the freed d-alanine to provide d-alanyl-lactate (VanA). This moiety is now incorporated in the normal peptidoglycan synthesis and is no longer susceptible to glycopeptide inhibition. On cross-linking during transpeptidation, the terminal lactate is removed, often by the non-essential gene product VanY [4] ( Figure 2). An additional non-essential gene (vanZ) has no known function. The vanA operon is inducible, which is also rare for a transferable resistance mechanism, by a two-component induction system. VanS is a transmembrane protein that autophosphorylates when it detects an incoming glycopeptide, which then phosphylates VanR that acts on the essential promoter of the operon. The vanA operon is effective against all glycopeptides that can initiate induction including teicoplanin. There are several similar operons in VRE; the second in importance is the vanB operon in Tn1547, which confers lower resistance to vancomycin and none to teicoplanin because this glycopeptide does not act as an inducer [5]. The vanC and vanE operons employ serine instead of lactate as the glycopeptide-insusceptible terminal moiety in the pentapeptide in peptidoglycan synthesis 4. and 6..