title: Association of IS5 with divergent tandem blaCMY-2 genes in clinical isolates of Escherichia coli.
abstract: OBJECTIVE
  To characterize a unique tandem bla(CMY-2) gene arrangement found in two non-identical clinical strains of Escherichia coli.
  
  
  METHODS
  Both plasmid and chromosomal DNA were evaluated using PFGE, restriction digest analysis, plasmid profiling and Southern hybridization. bla(CMY-2) gene expression and gene copy number were evaluated by real-time PCR. Susceptibilities to selected β-lactam antibiotics were determined by agar dilution.
  
  
  RESULTS
  A tandem arrangement for bla(CMY-2) was identified in both isolates and was the only arrangement for bla(CMY-2) observed. These isolates had distinct PFGE and plasmid profiles. Each strain exhibited 2-fold higher bla(CMY-2) mRNA expression and up to 8-fold lower β-lactam susceptibility compared with a strain with a single copy of bla(CMY-2).
  
  
  CONCLUSIONS
  This is the first report of IS5 being associated with tandem bla(CMY-2). IS5 has previously been associated with antibiotic resistance through tandem gene amplification. The unique tandem arrangement provides a mechanism for increased bla(CMY-2) expression.
authors.affiliation: Center for Research in Anti-Infectives and Biotechnology, Creighton University School of Medicine, Creighton University, 2500 California Plaza, Omaha, Nebraska 68127, USA.
authors.forename: Philip M
authors.initials: PM
authors.lastname: Kurpiel
authors.forename: Nancy D
authors.initials: ND
authors.lastname: Hanson
mesh_terms: D015139:Blotting, Southern; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology*; D005798:Genes, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D010957:Plasmids / Q000032:analysis; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; C103022:beta-lactamase CMY-2; D001618:beta-Lactamases