3-Deacetoxy-7-(alpha-amino-1-cyclohexenylacetamido) cephalosporanic acid (SCE-100), a new semisynthetic cephalosporin. II. Comparative in vivo antibacterial activities of SCE-100 and cephalexin (CEX).

The protective activity of 3-deacetoxy-7-(alpha-amino-1-cyclohexenylacetamido) cephalosporanic acid (SCE-100) against experimental intraperitoneal infections in mice caused by several strains of Gram-positive and Gram-negative organisms, including penicillin resistant strains, was compared with that of cephalexin (CEX). Comparable protective effects by oral administration of SCE-100 and CEX were observed in mice infected with Gram-positive organisms, while in mice infected with Gram-negative organisms SCE-100 was less active than CEX. SCE-100 showed a protective effect in infections of mice with either penicillin G-resistant Staphylococcus aureus or ampicillin-resistant Escherichia coli. The oral ED50 of SCE-100 was similar to or slightly larger than the subcutaneous value.