In vitro activity of imipenem and colistin against a carbapenem-resistant klebsiella pneumoniae isolate coproducing SHV-31, CMY-2, and DHA-1

Hung Jen Tang, Yee Huang Ku, Mei Feng Lee, Yin Ching Chuang, Wen Liang Yu

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6 Citations (Scopus)

Abstract

We investigated the synergism of colistin and imipenem against a multidrug-resistant K. pneumoniae isolate which was recovered from a severe hip infection. PCR and DNA sequencing were used to characterize the outer membrane porin genes and the resistance genes mediating the common β-lactamases and carbapenemases. Synergism was evaluated by time-kill studies. The b l a SHV-31, b l a CMY-2, and b l a DHA-1 were detected. Outer membrane porin genes analysis revealed loss of ompK36 and frame-shift mutation of ompK35. The common carbapenemase genes were not found. Time-kill studies demonstrated that a combination of 1x MIC of colistin (2 mg/L) and 1x MIC of imipenem (8 mg/L) was synergistic and bactericidal but with inoculum effect. Bactericidal activity without inoculum effect was observed by concentration of 2x MIC of colistin alone or plus 2x MIC of imipenem. In conclusion, colistin plus imipenem could be an alternative option to treat carbapenem-resistant K. pneumoniae infections.

Original languageEnglish
Article number568079
JournalBioMed Research International
Volume2015
DOIs
Publication statusPublished - 2015

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ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)

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