Carbapenem Resistance Caused by High-Level Expression of OXA-663 β-Lactamase in an OmpK36-Deficient Klebsiella pneumoniae Clinical Isolate

Antimicrob Agents Chemother. 2018 Oct 24;62(11):e01281-18. doi: 10.1128/AAC.01281-18. Print 2018 Nov.

Abstract

Carbapenem resistance is mainly mediated by carbapenemases or extended-spectrum β-lactamases (ESBL) plus a loss of porins. However, we have identified a Klebsiella pneumoniae clinical isolate that contains neither carbapenemases nor ESBLs. Instead, we found that high-level expression of a novel blaOXA-10-derived β-lactamase gene, blaOXA-663, in conjunction with OmpK36 deficiency results in high-level carbapenem resistance. This finding demonstrates the combinatorial complexity of factors, including β-lactamase activity, its expression levels, and porin activity, that yield carbapenem resistance.

Keywords: Klebsiella; OXA-663; carbapenem resistance; β-lactamases.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / genetics*
  • Carbapenems / pharmacology*
  • Drug Resistance, Bacterial / genetics*
  • Humans
  • Klebsiella Infections / diet therapy
  • Klebsiella Infections / microbiology
  • Klebsiella pneumoniae / drug effects*
  • Klebsiella pneumoniae / genetics*
  • Porins / genetics*
  • beta-Lactamases / genetics

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Carbapenems
  • OmpK36 protein, Klebsiella pneumoniae
  • Porins
  • beta-Lactamases
  • carbapenemase