DESPITE the availability of several different penicillins 1 for the treatment of infections caused by Gram-positive bacteria, there remained a need for a broad-spectrum penicillin which would also be effective orally against Gram-negative organisms. D-4-Amino4 carboxybutylpenicillin (Cephalosporin N, Synnematin B) shows promising activity against certain Gram-negative organisms, particularly Salmortellae, but must be administered by ...