Postantibiotic effect of ceftaroline against gram-positive organisms.

The postantibiotic effects (PAEs), postantibiotic sub-MIC effects (PA-SMEs), and sub-MIC effects (SMEs) of ceftaroline, a novel injectable cephalosporin, were determined for 15 gram-positive organisms. The pneumococcal, staphylococcal, and enterococcal PAEs were 0.8 to 1.8 h, 0.7 to 2.2 h, and 0.2 to 1.1 h, respectively. The corresponding PA-SMEs (0.4 times the MIC) were 2.5 to 6.7 h, 2.9 to >0.0 h, and 7.9 to >10.3 h, respectively. The PA-SMEs were longer than the PAEs, suggesting that sub-MIC levels extend the PAE of ceftaroline against gram-positive cocci.