Molecular and biochemical characterization of OXA-45, an extended-spectrum class 2d' beta-lactamase in Pseudomonas aeruginosa

Antimicrob Agents Chemother. 2003 Sep;47(9):2859-63. doi: 10.1128/AAC.47.9.2859-2863.2003.

Abstract

As part of the CANCER Antimicrobial Surveillance Program in North America, a clinical strain of Pseudomonas aeruginosa, strain 07-406, isolated in Texas was found to be resistant to all antimicrobials except polymyxin B. Genetic analysis of this isolate identified two unique extended-spectrum beta-lactamase genes. One, bla(VIM-7), encoded a metallo-beta-lactamase (unpublished data), and the other, bla(OXA-45), described here, encoded a class D extended-spectrum beta-lactamase. bla(OXA-45) was isolated on a Sau3A1 genomic fragment of 1.8 kb and encodes a protein of 264 amino acids with the highest identities to OXA-18 (65.9%), OXA-9 (42.8%), OXA-22 (40.2%), OXA-12 (38.6%), and OXA-29 (35.2%) but weak identities with other class D beta-lactamases. bla(OXA-45) was found to be harbored on a 24-kb plasmid in a region that displays high identities with a section of the 43-kb genomic island of Salmonella enterica serovar Typhimurium DT104. Biochemically OXA-45 is most similar to OXA-18 in its substrate profile and inhibition by clavulanic acid and is a member of the 2d' class of beta-lactamases.

MeSH terms

  • Amino Acid Sequence
  • Anti-Bacterial Agents / pharmacology
  • Aztreonam / pharmacology
  • Cloning, Molecular
  • DNA Primers
  • DNA, Bacterial / genetics
  • Drug Resistance, Bacterial
  • Isoelectric Focusing
  • Microbial Sensitivity Tests
  • Molecular Sequence Data
  • Monobactams / pharmacology
  • Oxacillin / pharmacology
  • Penicillin Resistance / genetics
  • Penicillins / pharmacology
  • Plasmids / genetics
  • Polymyxin B / pharmacology
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / enzymology
  • Pseudomonas aeruginosa / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • beta-Lactamases / chemistry
  • beta-Lactamases / genetics*

Substances

  • Anti-Bacterial Agents
  • DNA Primers
  • DNA, Bacterial
  • Monobactams
  • Penicillins
  • beta-Lactamases
  • beta-lactamase OXA-45, Pseudomonas aeruginosa
  • Aztreonam
  • Polymyxin B
  • Oxacillin