An approximately 60-kb transferable, vanB-carrying plasmid has been identified in a clinical Enterococcus faecium strain. A similar plasmid has been observed in an unrelated E. faecium strain, suggesting that plasmid transfer of vanB operons occurs in nature and plays a role in the dissemination of VanB-type resistance among strains of E. faecium.
Cleveland Department of Veterans Affairs Medical Center, Department of Medicine, Case Western Reserve University School of Medicine, Ohio 44106, USA. lbr@po.cwru.edu