Possible Horizontal Transfer of the vanB2 Gene among Genetically Diverse Strains of Vancomycin-Resistant Enterococcus faecium in a Korean Hospital

A total of 25 isolates of vanB-containing Enterococcus faecium were recovered from patients in a single Korean hospital over a 20-month period. There were two distinct vanB2 patterns among the 11 pulsed-field gel electrophoresis types; 17 contained the prototype vanB2 and 8 contained a novel vanB2 with a 177-bp deletion in vanY(B). Both vanB2 genes were transmissible in vitro at a mean frequency of 1.1 × 10(−8) transconjugants/donor. These results suggest the horizontal spread of vanB2 is occurring among genetically diverse strains of E. faecium in Korean hospitals.