Comparative activities of colistin, rifampicin, imipenem and sulbactam/ampicillin alone or in combination against epidemic multidrug-resistant Acinetobacter baumannii isolates producing OXA-58 carbapenemases

Int J Antimicrob Agents. 2007 Dec;30(6):537-40. doi: 10.1016/j.ijantimicag.2007.07.007. Epub 2007 Sep 11.

Abstract

This study evaluated the activity of colistin, rifampicin, imipenem and sulbactam/ampicillin alone or in combination against nine epidemic multidrug-resistant Acinetobacter baumannii isolates producing OXA-58 carbapenemase in Naples, Italy. The isolates were susceptible to colistin but differed in their resistance to imipenem and rifampicin. Time-kill studies showed a bactericidal effect for colistin but not for imipenem, rifampicin or sulbactam/ampicillin used as single agents. Synergism was observed with combinations of rifampicin+imipenem or sulbactam/ampicillin for all isolates and with colistin+rifampicin for isolates showing higher minimum inhibitory concentrations for rifampicin. Combined use of the antimicrobials tested may provide good therapeutic options for OXA-58 carbapenemase-producing A. baumannii infections.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter Infections / epidemiology*
  • Acinetobacter Infections / microbiology
  • Acinetobacter baumannii / drug effects*
  • Acinetobacter baumannii / enzymology
  • Acinetobacter baumannii / genetics
  • Acinetobacter baumannii / isolation & purification
  • Ampicillin / pharmacology
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins / biosynthesis*
  • Carbapenems / pharmacology
  • Colistin / pharmacology
  • Disease Outbreaks*
  • Drug Resistance, Multiple, Bacterial*
  • Drug Synergism
  • Electrophoresis, Gel, Pulsed-Field
  • Humans
  • Imipenem / pharmacology
  • Italy / epidemiology
  • Microbial Sensitivity Tests
  • Rifampin / pharmacology
  • Sulbactam
  • beta-Lactamases / biosynthesis*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Carbapenems
  • Imipenem
  • Ampicillin
  • beta-Lactamases
  • carbapenemase
  • Sulbactam
  • Rifampin
  • Colistin