Characterization of the new metallo-beta-lactamase VIM-13 and its integron-borne gene from a Pseudomonas aeruginosa clinical isolate in Spain

Antimicrob Agents Chemother. 2008 Oct;52(10):3589-96. doi: 10.1128/AAC.00465-08. Epub 2008 Jul 21.

Abstract

During a survey conducted to evaluate the incidence of class B carbapenemase (metallo-beta-lactamase [MBL])-producing Pseudomonas aeruginosa strains from hospitals in Majorca, Spain, five clinical isolates showed a positive Etest MBL screening test result. In one of them, strain PA-SL2, the presence of a new bla(VIM) derivative (bla(VIM-13)) was detected by PCR amplification with bla(VIM-1)-specific primers followed by sequencing. The bla(VIM-13)-producing isolate showed resistance to all beta-lactams (except aztreonam), gentamicin, tobramycin, and ciprofloxacin. VIM-13 exhibited 93% and 88% amino acid sequence identities with VIM-1 and VIM-2, respectively. bla(VIM-13) was cloned in parallel with bla(VIM-1), and the resistance profile conferred was analyzed both in Escherichia coli and in P. aeruginosa backgrounds. Compared to VIM-1, VIM-13 conferred slightly higher levels of resistance to piperacillin and lower levels of resistance to ceftazidime and cefepime. VIM-13 and VIM-1 were purified in parallel as well, and their kinetic parameters were compared. The k(cat)/K(m) ratios for the antibiotics mentioned above were in good agreement with the MIC data. Furthermore, EDTA inhibited the activity of VIM-13 approximately 25 times less than it inhibited the activity of VIM-1. VIM-13 was harbored in a class 1 integron, along with a new variant (Ala108Thr) of the aminoglycoside-modifying enzyme encoding gene aacA4, which confers resistance to gentamicin and tobramycin. Finally, the VIM-13 integron was apparently located in the chromosome, since transformation and conjugation experiments consistently yielded negative results and the bla(VIM-13) probe hybridized only with the genomic DNA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • Cloning, Molecular
  • DNA Primers / genetics
  • DNA, Bacterial / genetics
  • Genes, Bacterial*
  • Genetic Variation
  • Humans
  • Imipenem / pharmacology
  • Integrons
  • Kinetics
  • Meropenem
  • Molecular Sequence Data
  • Phylogeny
  • Pseudomonas Infections / drug therapy
  • Pseudomonas Infections / microbiology
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / enzymology*
  • Pseudomonas aeruginosa / genetics*
  • Pseudomonas aeruginosa / isolation & purification
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Spain
  • Thienamycins / pharmacology
  • beta-Lactam Resistance / genetics
  • beta-Lactam Resistance / physiology
  • beta-Lactamases / genetics*
  • beta-Lactamases / metabolism*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • DNA Primers
  • DNA, Bacterial
  • Recombinant Proteins
  • Thienamycins
  • Imipenem
  • VIM-1 metallo-beta-lactamase
  • metallo-beta-lactamase (VIM-13), Pseudomonas aeruginosa
  • beta-Lactamases
  • Meropenem

Associated data

  • GENBANK/DQ365886
  • GENBANK/EF577407
  • GENBANK/EF577408