title: The new variant of Salmonella genomic island 1 (SGI1-V) from a Proteus mirabilis French clinical isolate harbours blaVEB-6 and qnrA1 in the multiple antibiotic resistance region.
abstract: OBJECTIVE
  The clinical strain of Proteus mirabilis VB1248 isolated from a blood culture in August 2009 was multiresistant (i.e. resistant to β-lactams, fluoroquinolones, aminoglycosides and sulphonamides). We searched for the presence of a Salmonella genomic island 1 (SGI1).
  
  
  METHODS
  The whole genetic structure surrounding the genes involved in antibiotic resistance was characterized by PCR or gene walking followed by DNA sequencing.
  
  
  RESULTS
  The new variant SGI1-V (42.9 kb) was located downstream of the thdF chromosomal gene. Genes sharing homology with phage-related genes were detected on a structure of 8.3 kb located between the right junction of the SGI1-V and the hipB/hipA genes. Some genetic rearrangements occurred in the SGI1-V backbone: an insertion of 2349 bp within the open reading frame (ORF) S014, and a deletion of 3766 bp in the region spanning from ORFs S021 to S025 leading to the lack of ORFs S023 and S024. The multidrug resistance (MDR) region of 17.1 kb was located on a complex class 1 integron extremely different from those described so far. The cassette array included aacA4, aadB and dhfrA1. Adjacent to this classical structure, bla(VEB-6) was found flanked by 135 bp elements and bracketed by two 3'-conserved segments (3'-CS). Downstream of the second copy of 3'-CS, the qnrA1 gene was associated with common region 1.
  
  
  CONCLUSIONS
  We have identified in P. mirabilis the new variant SGI1-V containing the bla(VEB-6) and qnrA1 genes in the MDR region. This is the first report of an extended-spectrum β-lactamase-encoding gene and a qnr determinant conferring resistance to quinolones on an SGI1-like structure. It might constitute a source of spread of resistance to other bacterial species.
authors.affiliation: Laboratory of Bacteriology, University Hospital of Dijon, Plateau technique de Biologie, BP 37013, 21070 Dijon cedex, France.
authors.forename: Eliane
authors.initials: E
authors.lastname: Siebor
authors.forename: Catherine
authors.initials: C
authors.lastname: Neuwirth
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D024841:Fluoroquinolones / Q000494:pharmacology; D044404:Genomic Islands; D006801:Humans; D032023:Integrons / Q000235:genetics; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008969:Molecular Sequence Data; D011512:Proteus Infections / Q000188:drug therapy / Q000382:microbiology* / Q000401:mortality; D011513:Proteus mirabilis / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D012475:Salmonella / Q000187:drug effects / Q000235:genetics; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D024841:Fluoroquinolones; D001618:beta-Lactamases