Transferable, plasmid-mediated vanB-type glycopeptide resistance in Enterococcus faecium

Abstract

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.

FIG. 1

Comparison of HincII digestions of plasmid preparations from GE-1(pLRM19) and GE-1(pLRM20). Lane 1, bacteriophage lambda digested with HindIII (size standard—sizes denoted on left side of figure); lane 2, GE-1(pLRM20); lane 3, GE-1(pLRM19); lane 4, High-molecular-weight size standards (Bethesda Research Laboratories, Gaithersburg, Md.) (relevant sizes denoted on right side of figure); lanes 5 and 6, Southern transfer of digests at left hybridized with 2.1-kb EcoRV fragment internal to the vanH_BBX_B operon; lanes 7 and 8, Southern transfer of digests at left hybridized with 1.8-kb AccI fragment of pLRM19 (see text).