In vivo targeting of E. coli with vancomycin-arginine.

The ability of vancomycin-arginine (V-r) to extend the spectrum of activity of glycopeptides to gram-negative bacteria was investigated. Its MIC towards E. coli including β-lactamase expressing Ambler classes A, B, and D was 8-16μg/ml. Addition of 8×MIC V-r to E. coli was acutely bactericidal and associated with a low frequency of resistance ( 7 log10 CFU/g in a thigh muscle model. These data warrant further development of V-r in combatting E. coli, including resistant forms.