title: [IS CR1 associated with bla CTX-M-1 y bla CTX-M-2 genes in IncN and IncFIIA plasmids isolated from Klebsiella pneumoniae of nosocomial origin in Mérida, Venezuela].
abstract: BACKGROUND
  Insertion sequences such as IS CR1 promote capture, transposition and expression of bla CTX-M genes. Thus, gene dissemination in bacterial populations occurs rapidly.
  
  
  OBJECTIVE
  To determine the presence of IS CR1 sequence genes and their association with bla CTX-M-1 and bla CTX-M-2 on plasmids IncN and IncFIIA from K. pneumoniae of nosocomial origin, was determined.
  
  
  METHODS
  Three strains of K. pneumoniae with reduced susceptibility to extendedspectrum cephalosporins were isolated from neonatal sepsis cases of nosocomial origin. Phenotypic tests showed the presence of ESBLs. Plasmids were isolated and classified according to incompatibility groups by PCR replicon typing. Detection and association of IS CR1 with bla CTX-M genes were determined by PCR and direct sequencing through the use of several sets of PCR primers.
  
  
  RESULTS
  All strains showed phenotypic profile consistent with ESBL-producing transferred by conjugation. PCR amplification assay for CTX-M together with sequencing analysis revealed that strains carrying bla CTX-M-1 y bla CTX-M-2 genes were localized in plasmids of approximately 150 kb related to IncN and IncFIIA groups, respectively. IS CR1 was found upstream and associated with bla CTX-M-1 y bla CTX-M-2 genes. CONCLUSION Thus far, this is the first Venezuelan report, in which IS CR1 presence is closely related to bla CTX-M-1 y bla CTX-M-2 gene mobilization in IncN and IncFIIA conjugative plasmids located in K. pneumonaiae strains circulating at a neonatal high risk unit.
authors.affiliation: Laboratorio de Microbiología Molecular, Facultad de Farmacia y Bioanálisis, Universidad de Los Andes.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Millán
authors.affiliation: Laboratorio de Microbiología Molecular, Facultad de Farmacia y Bioanálisis, Universidad de Los Andes.
authors.forename: David
authors.initials: D
authors.lastname: Castro
authors.affiliation: Laboratorio de Microbiología Molecular, Facultad de Farmacia y Bioanálisis, Universidad de Los Andes.
authors.forename: María
authors.initials: M
authors.lastname: Araque
authors.affiliation: Cátedra de Microbiología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires.
authors.forename: Bárbara
authors.initials: B
authors.lastname: Ghiglione
authors.affiliation: Cátedra de Microbiología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Gutkind
mesh_terms: D003428:Cross Infection / Q000382:microbiology; D006801:Humans; D007711:Klebsiella pneumoniae / Q000235:genetics* / Q000302:isolation & purification; D010957:Plasmids / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014687:Venezuela; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: C515384:beta-lactamase CTX-M-2, Klebsiella pneumoniae; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases