Characterization of the highly variable region surrounding the bla(CTX-M-9) gene in non-related Escherichia coli from Barcelona

J Antimicrob Chemother. 2005 Nov;56(5):819-26. doi: 10.1093/jac/dki345. Epub 2005 Sep 27.

Abstract

Objectives: The dispersion of a clone, a plasmid or a mobile element carrying the bla(CTX-M-9) gene was evaluated in 30 Escherichia coli strains isolated in Barcelona between 1996 and 1999. The presence of the previously described orf513-bearing class 1 integron, In60, carrying the bla(CTX-M-9) gene, was also studied.

Methods: The clonality was analysed by pulsed-field gel electrophoresis. Plasmid analysis was performed by S1 digestion and hybridization with the CTX-M-9 probe. PCR mapping using specific designed primers was used to study the presence of In60 and In60-like structures.

Results: The clonality between the 30 strains was minor. The size of bla(CTX-M-9) carrying plasmids ranged between approximately 80 and 430 kb. One strain produced only a chromosome-encoded CTX-M-9 beta-lactamase. Thirty-six per cent of the strains showed differences with respect to the In60 structure due to an insertion or deletion events.

Conclusions: These findings suggest that the bla(CTX-M-9) gene may be carried by a mobile element that disperses it between plasmids. The fast dispersion of the CTX-M-9 enzyme could therefore be due to both diffusion of plasmids and mobile elements.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Chromosomes, Bacterial / genetics
  • DNA Fingerprinting
  • DNA Transposable Elements / genetics
  • DNA, Bacterial / analysis
  • DNA, Bacterial / genetics
  • Electrophoresis, Gel, Pulsed-Field
  • Escherichia coli / enzymology
  • Escherichia coli / genetics*
  • Escherichia coli / isolation & purification
  • Escherichia coli Infections / microbiology
  • Escherichia coli Proteins / genetics*
  • Gene Order
  • Humans
  • Integrons / genetics
  • Molecular Epidemiology
  • Molecular Sequence Data
  • Nucleic Acid Hybridization
  • Plasmids / genetics
  • Polymerase Chain Reaction
  • Polymorphism, Genetic
  • Polymorphism, Restriction Fragment Length
  • Spain
  • beta-Lactamases / genetics*

Substances

  • DNA Transposable Elements
  • DNA, Bacterial
  • Escherichia coli Proteins
  • CTX-M-9 protein, E coli
  • beta-Lactamases

Associated data

  • GENBANK/AY512972
  • GENBANK/AY557605
  • GENBANK/AY557606