VANCOMYCIN RESISTANCE GENE VANC IS SPECIFIC TO ENTEROCOCCUS-GALLINARUM

Nearly all strains of Enterococcus gallinarum are resistant to low levels of vancomycin. The glycopeptide resistance gene vanC from E. gallinarum BM4174 has recently been cloned and sequenced. A probe specific for vanC hybridized with a 2.7-kb EcoRI and a 4.5-kb HindIII fragment of total DNA from the 42 strains of E. gallinarum studied. No homology was detected with DNA of strains belonging to other species intrinsically resistant to vancomycin, including Enterococcus casseliflavus, a species that expresses a vancomycin resistance phenotype similar to that of E. gallinarum. No hybridization with DNA of enterococcal strains with acquired resistance to high or low levels of vancomycin was observed. The specificity of the vanC probe allowed us to distinguish E. gallinarum from 12 other species of enterococci, indicating that this probe is a useful tool for species identification within the genus Enterococcus.