EFFECT OF CLAVULANIC ACID, SULBACTAM AND TAZOBACTAM ON 3 DIFFERENT BETA-LACTAMASES FROM BACTEROIDES-UNIFORMIS, CLOSTRIDIUM-BUTYRICUM AND FUSOBACTERIUM-NUCLEATUM

The effect of three I-lactamase inhibitors, clavulanic add, sulbactam and tazo-bactam used in clinical practice were compared for their activity against purified I-lactamases from Bacteroides uniformis, Clostridium butyricum and Fusobacterium nucleatum. The enzymes from B. uniformis and C. butyricum were produced in fermenters under controlled growth conditions and the enzyme from F. nucleatum was produced in batch cultures. Purification of the I-lactamases was achieved by anion-exchange chromatography, gel filtration and FPLC-technique. The degree of inactivation of I-lactamase activity was determined spectrophotometrically with nitrocefin as the substrate. The inhibitors in various concentrations were pre-incubated at 30°C together with the enzyme for different time periods (0°5-120 min) before determination of the remaining I-lactamase activity. The inhibitors all decreased the activity of the I-lactamases investigated. Clavulanic add and sulbactam were capable of reducing the enzyme activity of the B. uniformis I-lactamase more effectively than the C. butyricum and F. nucleatum I-lactamases. All I-lactamases tested were more susceptible to tazobactam than to clavulanic add and sulbactam. © 1992 Oxford University Press.