In-vitro activity of LY 146032, a novel cyclic lipopeptide, alone and in combination with gentamicin or tobramycin against enterococci

The in-vitro activity of LY 146032, a novel cyclic lipopeptide and the effect of the combination of LY 146032 and gentamicin or tobramycin against 25 strains of enterococci isolated from blood cultures were studied. All strains of enterococci were inhibited by less than or equal to 2 mg/l LY 146032. The minimal inhibitory concentrations and minimal bactericidal concentrations were within one dilution. In the time-kill study, there was slow bactericidal activity. Complete killing of 10(7) cfu/ml of enterococci at 48 h by LY 146032 alone occurred with two strains. There was synergism between LY 146032 and gentamicin or tobramycin; complete killing at 24 h and 48 h occurred with many strains. No antagonism was demonstrated.