Antibacterial activity of citreamicin-alpha (LL-E 19085 alpha) against gram-positive cocci

In vitro antibacterial activity of 429 clinical isolates of gram-positive cocci was tested against citreamicin-alpha (LL-E 19085-alpha) by the agar dilution method. The microorganisms consisted of 313 isolates of staphylococci and 116 strains of streptococci. In vitro activity of citreamicin-alpha was compared with ampicillin, augmentin, cephalothin, erythromycin and vancomycin. MICs of citreamicin-alpha for staphylococci ranged between 0.12-4.0 micrograms/ml and 0.03-0.12 micrograms/ml for Streptococcus pyogenes. Enterococci, however, were relatively more resistant, requiring 2.0 micrograms/ml of this drug to inhibit 64% of the 62 isolates tested. In vitro activity of this antibacterial agent was far superior to that of ampicillin, augmentin, cephalothin and erythromycin, but equal to or slightly inferior to that of vancomycin.