ximately 7.95??; (d) it possesses antibacterial activity against various species including, inter alia, strains of Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella aerogenes, Proteus mirabilis, Acinetobacter anitratus, Serratia marcescens and Shigella sonnei; (e) it synergizes the antibacterial activity of ampicillin against certain ??-lactamase producing bacteria including s