In vitro and in vivo antibacterial activities of cefoperazone/tazobactam

Objective:To evaluate the in vitro and in vivo antibacterial activities of cefoperazone/tazobactam.Methods:The in vitro antibacterial activity of cefoperazone/tazobactam was determined by use of clinical isolated bacteria and standard agar dilution method.Its in vivo antibacterial activity was determined in mice with experimental systemic infection caused by S.aureus,E.coli and K.pneumoniae.Results:The antibacterial activities of cefoperazone/tazobactam 4∶1 and 8∶1 were superior to those of 16∶1 and cefoperazone,inferior to those of 1∶1 and 2∶1 against 721 clinical isolated bacteria.The activities of cefoperazone/tazobactam 4∶1 and 8∶1 were 2 to 4 times stronger than those of cefoperazone against β-lactamases-producing S.aureus,E.coli,K.pneumoniae,P.mirabilis,A.calcoacetius,E.cloaceae,E.aerogenes,E.agglomerans,C.diversus and S.marcescens,and 8 to 32 times stronger than those of cefoperazone against ESBLs-producing E.coli and K.pneumoniae.The MBCs of cefoperazone/tazobactam 4∶1 and 8∶1 were similar to the MICs against S.aureus,E.coli and Ps.aeruginosa.The inoculum size,pH and serum have no effect on the MICs of cefoperazone/tazobactam 4∶1 and 8∶1 against S.aureus and E.coli.The in vivo antibacterial activities of cefoperazone/tazobactam 4∶1 and 8∶1 were similar to that of cefoperazone/sulbactam and superior to those of cefoperazone and piperacillin/tazobactam in mice infected with S.aureus,E.coli and K.pneumoniae.Conclusion:Cefoperazone/tazobactam 4∶1 and 8∶1 had excellent and similar antibacterial activities.The antibacterial activities of cefoperazone against the clinical isolated bacteria were improved by combination of tazobactam.