In Vitro Activities of the Lipopeptides Palmitoyl (Pal)-Lys-Lys-NH 2 and Pal-Lys-Lys Alone and in Combination with Antimicrobial Agents against Multiresistant Gram-Positive Cocci

The in vitro activities of the lipopeptides palmitoyl (Pal)-Lys-Lys-NH 2 and Pal-Lys-Lys against gram-positive cocci were investigated. Enterococci and streptococci demonstrated higher susceptibilities than staphylococci and Rhodococcus equi . A positive interaction was shown when the lipopeptides were combined with beta-lactams and vancomycin. These results suggest that lipopeptides are promising candidates for antimicrobial therapy for infections caused by gram-positive organisms.