In Vitro Activities of Ceftazidime-Avibactam, Aztreonam-Avibactam, and a Panel of Older and Contemporary Antimicrobial Agents against Carbapenemase-Producing Gram-Negative Bacilli

Antimicrob Agents Chemother. 2015 Dec;59(12):7842-6. doi: 10.1128/AAC.02019-15. Epub 2015 Sep 21.

Abstract

Among 177 carbapenemase-producing Gram-negative bacilli (108 KPC, 32 NDM, 11 IMP, 8 OXA-48, 4 OXA-181, 2 OXA-232, 5 IMI, 4 VIM, and 3 SME producers), aztreonam-avibactam was active against all isolates except two NDM producers with elevated MICs of 8/4 and 16/4 mg/liter; ceftazidime-avibactam was active against all KPC-, IMI-, SME-, and most OXA-48 group-producing isolates (93%) but not metallo-β-lactamase producers. Among older and contemporary antimicrobials, the most active were colistin, tigecycline, and fosfomycin, with overall susceptibilities of 88%, 79%, and 78%, respectively.

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Azabicyclo Compounds / pharmacology*
  • Aztreonam / pharmacology*
  • Bacterial Proteins / classification
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Ceftazidime / pharmacology*
  • Colistin / pharmacology
  • Drug Combinations
  • Enterobacteriaceae / drug effects*
  • Enterobacteriaceae / enzymology
  • Enterobacteriaceae / genetics
  • Enterobacteriaceae / growth & development
  • Fosfomycin / pharmacology
  • Gene Expression
  • Humans
  • Microbial Sensitivity Tests
  • Minocycline / analogs & derivatives
  • Minocycline / pharmacology
  • Tigecycline
  • beta-Lactamases / classification
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism

Substances

  • Anti-Bacterial Agents
  • Azabicyclo Compounds
  • Bacterial Proteins
  • Drug Combinations
  • avibactam, ceftazidime drug combination
  • Fosfomycin
  • Tigecycline
  • avibactam
  • Ceftazidime
  • beta-Lactamases
  • carbapenemase
  • Minocycline
  • Aztreonam
  • Colistin