Genetic and Biochemical Characterization of the Chromosome-Encoded Class B Beta-Lactamases From Shewanella Livingstonensis (SLB-1) and Shewanella Frigidimarina (SFB-1)

J Antimicrob Chemother. 2005 May;55(5):680-5. doi: 10.1093/jac/dki065. Epub 2005 Mar 16.

Abstract

Objectives: To determine the beta-lactamase gene content of beta-lactam-susceptible psychrophilic gram-negative bacilli, Shewanella frigidimarina and Shewanella livingstonensis, isolated from a marine environment.

Methods: Beta-lactamase genes were cloned, sequenced and expressed in Escherichia coli. Kinetic parameters were determined using purified enzymes.

Results: Metallo-beta-lactamases SLB-1 and SFB-1 were identified from S. livingstonensis and S. frigidimarina, respectively, sharing 65% amino acid identity and being distantly related to other Ambler class B beta-lactamases (40 and 36% amino acid identity with GIM-1 and IMP-1 from Pseudomonas aeruginosa, respectively). SLB-1 had an EDTA-inhibited and broad-spectrum beta-lactam hydrolysis profile, whereas SFB-1 did not hydrolyse cephalosporins, with activity being weakly inhibited by EDTA and dipicolinic acid.

Conclusions: This work provides further evidence that psychrophilic bacterial species may constitute a reservoir of beta-lactam resistance genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Chromosomes, Bacterial / genetics*
  • Cloning, Molecular
  • Microbial Sensitivity Tests
  • Molecular Sequence Data
  • Sequence Analysis, DNA
  • Shewanella / classification
  • Shewanella / drug effects
  • Shewanella / enzymology*
  • Shewanella / genetics
  • beta-Lactam Resistance
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism*
  • beta-Lactams / pharmacology*

Substances

  • beta-Lactams
  • beta-Lactamases

Associated data

  • GENBANK/AY590118
  • GENBANK/AY590119