First Report of a Novel Extended-Spectrum Beta-Lactamase KOXY-2 Producing Klebsiella oxytoca that Hydrolyses Cefotaxime and Ceftazidime

A. Younes, A. Hamouda, S. G. B. Amyes*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Klebsiella oxytoca strains MU946294N and MB193997E were isolated from patients in Scotland. Strain MU946294N was resistant to pencillins, monbactams and cephalosporins. Isolate MB193997E displayed a beta-lactam resistance phenotype consistent with chromosomal beta-lactamase overproduction. No bla(TEM), bla(SHV) or bla(CTX-M) genes could be amplified in either strain; however, amplification by PCR was found with primers for the bla(OXY-2) gene. This beta-lactamase gene in MU946294N differed by one mutation from the all other bla(OXY) genes previously reported, with an amino acid substitution Alanine237 Threonine enhancing the binding of cefotaxime. Strain MB193997E showed mutations at positions 255 and 283, neither of which affect function. Based on rpoB and gyrA characterization, both strains were assigned to the KoII phylogenic group but they were completely dissimilar from each other by PFGE. This study is the first to report the substitution of Alanine to Threonine at position 237 in a OXY-2 beta-lactamase and this enhances resistance to cefotaxime.

Original languageEnglish
Pages (from-to)127-130
Number of pages4
JournalJournal of chemotherapy
Volume23
Issue number3
Publication statusPublished - Jun 2011

Keywords

  • SCHEME
  • OUTBREAK
  • bla(OXY-2)
  • PNEUMONIAE
  • HOSPITALS
  • PFGE
  • ENZYME
  • STRAINS
  • OVERPRODUCTION
  • FIELD GEL-ELECTROPHORESIS
  • cefotaxime resistance
  • RESISTANCE
  • EPIDEMIOLOGY

Cite this