In vitro activity and killing effect of citropin 1.1 against gram-positive pathogens causing skin and soft tissue infections

The in vitro activity of citropin 1.1 against gram-positive cocci was measured by MIC, minimal bactericidal concentration, time-kill studies, and a checkerboard titration method. Streptococci and staphylococci were inhibited at concentrations between 1 and 16 mg/liter, respectively. Enterococci showed less susceptibility. Synergy was demonstrated when citropin 1.1 was combined with clarithromycin and doxycycline.