Comparative activities of LY 333328, a new glycopeptide, against penicillin-susceptible and -resistant pneumococci

Microdilution MIC testing was used to test the susceptibility of 202 pneumococci to LY 333328 and six other agents. LY 333328 was the most active glycopeptide (MIG at which 90% of the pneumococci were inhibited [MIC(90)], 0.008 mu g/ml), followed by teicoplanin (MIC(90), 0.06 mu g/ml) and vancomycin (MIC(90), 0.5 mu g/ml). Rifampin resistance was seen in some penicillin-resistant strains. The MICs of imipenem and ceftriaxone rose with those of penicillin. Time-kill testing confirmed the excellent antipneumococcal activity of LY 333328.