Susceptibility survey of piperacillin alone and in the presence of tazobactam

J Antimicrob Chemother. 1993 Jan;31 Suppl A:23-8. doi: 10.1093/jac/31.suppl_a.23.


Among 325 fresh isolates of bacteria from 153 hospital patients with serious infections, 142 were susceptible to piperacillin, 129 were resistant and a further 54 exhibited a marked inoculum effect. Tazobactam restored the susceptibility of resistant isolates of Staphylococcus aureus and Staphylococcus epidermidis (except methicillin-resistant isolates), Haemophilus influenzae, Moraxella catarrhalis, Acinetobacter spp. and Bacteroides fragilis. Among 87 Enterobacteriaceae that were resistant to piperacillin, or showed an inoculum effect, 78 (89%) were restored to susceptibility by tazobactam. Pseudomonas spp. resistant to piperacillin were mostly resistant to the combination.

MeSH terms

  • Bacteria / drug effects*
  • Bacterial Infections / microbiology
  • Drug Resistance, Microbial
  • Drug Therapy, Combination / pharmacology
  • Gram-Negative Bacteria / drug effects
  • Humans
  • Methicillin Resistance
  • Microbial Sensitivity Tests
  • Penicillanic Acid / pharmacology*
  • Piperacillin / pharmacology*
  • Tazobactam
  • beta-Lactamase Inhibitors*


  • beta-Lactamase Inhibitors
  • Penicillanic Acid
  • Tazobactam
  • Piperacillin