High-dose ampicillin-sulbactam combinations combat polymyxin-resistant Acinetobacter baumannii in a hollow-fiber infection model

Justin R Lenhard, Nicholas M. Smith, Zackery P. Bulman, Xun Tao, Visanu Thamlikitkul, Beom Soo Shin, Roger L Nation, Jian Li, Jurgen B Bulitta, Brian T Tsuji

Research output: Contribution to journalArticleResearchpeer-review

54 Citations (Scopus)


Acinetobacter baumannii is emerging with resistance to polymyxins. In 24-h time-kill experiments, high-dose ampicillin-sulbactam in combination with meropenem and polymyxin B achieved additivity or synergy against 108 CFU/ml of two clinical A. baumannii isolates resistant to all three drugs (maximum reductions, 1.6 and 3.1 logs). In a 14-day hollow-fiber infection model, high-dose ampicillin-sulbactam (8/4 g every 8 h, respectively) in combination with meropenem (2 g every 8 h) and polymyxin B (1.43 mg/kg of body weight every 12 h with loading dose) resulted in rapid (96 h) eradication of A. baumannii.

Original languageEnglish
Article numbere01268
Number of pages6
JournalAntimicrobial Agents and Chemotherapy
Issue number3
Publication statusPublished - 1 Mar 2017


  • Acinetobacter
  • Antibiotic resistance
  • Antimicrobial combinations
  • Meropenem
  • Polymyxins
  • Sulbactam
  • Synergism

Cite this