Molecular genetic analysis of high-level gentamicin resistance in Enterococcus hirae.

High-level resistance to gentamicin was studied in seven clinical isolates of Enterococcus hirae. In common with other members of the genus Enterococcus, such resistance in E. hirae was associated with single, large, conjugative plasmids. Molecular genetic analysis revealed five distinct plasmid types amongst the seven isolates. The determinant mediating high-level gentamicin resistance in E. hirae was also shown to be homologous to that already characterized for other enterococcal species.