EFFICACY OF CEFOPERAZONE IN COMBINATION WITH SULBACTAM IN EXPERIMENTAL STAPHYLOCOCCUS-AUREUS ENDOCARDITIS IN RABBITS

The activity of cefoperazone with and without sulbactam was studied in vitro and in vivo against strains of methicillin-resistant and methicillin-susceptible Staphylococcus aureus. Cefoperazone with or without sulbactam was inactive in vitro against the methicillin-resistant strain and was bound by penicillin-binding protein 2a with an IC50 of 190 mg/L (the concentration that reduced radio-labelling with 3H-penicillin by 50%). Cefoperazone was hydrolysed by β-lactamasc in vitro but sulbactam improved cefoperazone activity in a rabbit model of aortic valve endocarditis caused by a β-lactamase producing methicillin-susceptible strain. © 1993 The British Society for Antimicrobial Chemotherapy.