In vitro antibacterial activity of echinomycin and a novel analogue, YK2000, against vancomycin-resistant enterococci

Abstract

The in vitro inhibitory and bactericidal activity of echinomycin and its the novel synthetic analogues of echinomycin YK2000 and YK2005, were evaluated using 93 clinical isolates of vancomycin-resistant enterococci (VRE). In agar dilution tests, the MIC90 of echinomycin and YK2000 were 0.125 and 8mg/l, respectively, using Mueller-Hinton 11 agar, while that of YK2005 was 32mg/l. Bactericidal activity of echinomycin and YK2000 were two to four times higher than the MIC in time-kill assay experiments. These results suggest that echinomycin and its analogues might be useful as anti-VRE drugs. (C) 2004 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.