In vitro and in vivo antibacterial activities of S-1090, a new oral cephalosporin.

S-1090, a new oral cephalosporin, was active against selected gram-negative bacteria and methicillin-susceptible clinical isolates of Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus warneri, against which it had excellent activity. S-1090 was the most active compound against Streptococcus pyogenes and Streptococcus agalactiae among the agents compared. The in vivo efficacy of S-1090 against systemic and urinary and respiratory tract infections caused by gram-positive and -negative bacteria was superior to that expected from the in vitro and in vivo activities of the agents against which it was compared.