Comparative Activity and β-Lactamase Stability of Cefoperazone, a Piperazine Cephalosporin

The in vitro activity and β-lactamase stability of 7-[d(−)-α-(4-ethyl-2,3-dioxopiperazino-carbonylamino) - p -hydroxyphenylacetamido]-3-[(1-methyl)-5-tetrazolylthiomethyl] -Δ 3 -cephem-4-carboxylic acid (cefoperazone), a cephalosporin analog of piperacillin, were compared with the activities and stabilities of other cephalosporins and cephamycins. The compound was less active than cephalothin or cefamandole in inhibiting Staphylococcus aureus ; it was as active as cefamandole and cefoxitin against most of the Enterobacteriaceae but less active than cefotaxime. It was more active than carbenicillin or piperacillin against Pseudomonas aeruginosa . In general, the compound was not active against Bacteroides . It was hydrolyzed by the β-lactamases of some Escherichia coli which hydrolyzed cefamandole, but was stable to most plasmid-mediated, chromosomally mediated, inducible β-lactamases in the Enterobacteriaceae and Pseudomonas .