Tazobactam is a β-lactamase inhibitor with greater activity against Ambler class A serine penicillinases and class C cephalosporinases, including TEM-1, SHV-1, and P99 (IC50s = 97, 150, and 8.5 nM, respectively) than class B metallo-β-lactamases and the class D oxacillinase OXA-1 (IC50s = 400,000 and 1,400 nM, respectively).1 However, it also inhibits the class D oxacillinase OXA-2 (IC50 = 10 nM). Tazobactam, in combination with piperacillin, is active against Gram-positive (MIC90s = 2-128 ?g/ml) and Gram-negative bacteria (MIC90s = 4-128 ?g/ml).2 In a neutropenic mouse model of thigh infection, tazobactam potentiates the activity of ceftolozane against Enterobacteriaceae.3 Formulations containing tazobactam, alone and in combination with piperacillin, have been used in the treatment of β-lacatamase-producing bacteria.
1.Drawz, S.M., and Bonomo, R.A.Three decades of β-lactamase inhibitorsClin. Microbiol. Rev.23(1)160-201(2010) 2.Jones, R.N., Pfaller, M.A., Fuchs, P.C., et al.Piperacillin/tazobactam (YTR 830) combination. Comparative antimicrobial activity against 5889 recent aerobic clinical isolates and 60 Bacteroides fragilis group strainsDiagn. Microbiol. Infect. Dis.12(6)489-494(1989) 3.Craig, W.A., and Andes, D.R.In vivo activities of ceftolozane, a new cephalosporin, with and without tazobactam against Pseudomonas aeruginosa and Enterobacteriaceae, including strains with extended-spectrum β-lactamases, in the thighs of neutropenic miceAntimicrob. Agents Chemother.57(4)1577-1582(2013)