In vitro susceptibility studies of vancomycin-resistant Enterococcus faecalis.

摘要: Vancomycin resistance exhibited by Enterococcus faecalis isolates V583, V586, and V587 is described. The vancomycin MICs ranged from 32 to 64 micrograms/ml. Although resistant vancomycin, the were susceptible teicoplanin (MIC, less than or equal 0.5 micrograms/ml). Such a glycopeptide susceptibility profile has not been previously described for E. faecalis. Time kill studies showed that adversely affected synergistic activity aminoglycoside combinations usually demonstrate against enterococci. However, ability detect varied with testing method used. Whereas broth microdilution, macrodilution, agar dilution methods detected resistance, disk-agar diffusion AutoMicrobic system Gram-Positive GPS-A card (Vitek Systems Inc., Hazelwood, Mo.) did not. To reliably establish incidence of such isolates, adjustments in some may be necessary.