title: Experimental evidence for IS1294b-mediated transposition of the blaCMY-2 cephalosporinase gene in Enterobacteriaceae.
abstract: OBJECTIVE
  The objective of this study was to investigate whether the insertion sequence IS1294b (IS91 family) is able to mobilize the blaCMY-2 gene and its adjacent regions from one replicon to another.
  
  
  METHODS
  Klebsiella pneumoniae Kp2735 was typed by MLST and its plasmid content was examined by S1-PFGE and PCR-based replicon typing. The genetic blaCMY-2 environment was analysed after cloning experiments and sequencing. Transposition assays were performed with an inactivation strategy based on the sacB gene, which confers sucrose-dependent lethality.
  
  
  RESULTS
  Kp2735 (ST215) exhibited high-level resistance to ceftazidime owing to the presence of the cephalosporinase CMY-2. The blaCMY-2 gene was located on an IncI1 ST156 plasmid, p2735, of ∼95 kb. Analysis of the genetic environment revealed, upstream of blaCMY-2, the presence of ISEcp1 interrupted by IS1294b and, downstream of blaCMY-2, a region of 1395 bp belonging to the backbone of IncA/C replicons, suggesting a possible DNA transfer between the two plasmids. We showed that IS1294b is able to mobilize blaCMY-2 and its adjacent regions efficiently on the recipient plasmid with a mean frequency of 5.9%. This transfer was due to a one-ended transposition mechanism, implying the non-recognition of its terIS end.
  
  
  CONCLUSIONS
  Our experimental data demonstrate for the first time, to our knowledge, the mobilization of a β-lactamase gene mediated by a member of the IS91 family and highlight the important role of this mobile genetic element in the spread of antibiotic resistance genes.
authors.affiliation: Université de Bordeaux, UMR CNRS 5234, Laboratoire de Microbiologie Fondamentale et Pathogénicité, Bordeaux, France.
authors.forename: Haytham
authors.initials: H
authors.lastname: Yassine
authors.affiliation: Université de Bordeaux, UMR CNRS 5234, Laboratoire de Microbiologie Fondamentale et Pathogénicité, Bordeaux, France.
authors.forename: Léa
authors.initials: L
authors.lastname: Bientz
authors.affiliation: Université de Bordeaux, UMR CNRS 5234, Laboratoire de Microbiologie Fondamentale et Pathogénicité, Bordeaux, France.
authors.forename: Jessica
authors.initials: J
authors.lastname: Cros
authors.affiliation: Université de Bordeaux, UMR CNRS 5234, Laboratoire de Microbiologie Fondamentale et Pathogénicité, Bordeaux, France Laboratoire de Bactériologie, CHU Bordeaux, Bordeaux, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Goret
authors.affiliation: Laboratoire de Bactériologie, CHU Bordeaux, Bordeaux, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Bébéar
authors.affiliation: Université de Bordeaux, UMR CNRS 5234, Laboratoire de Microbiologie Fondamentale et Pathogénicité, Bordeaux, France.
authors.forename: Claudine
authors.initials: C
authors.lastname: Quentin
authors.affiliation: Université de Bordeaux, UMR CNRS 5234, Laboratoire de Microbiologie Fondamentale et Pathogénicité, Bordeaux, France corinne.arpin@u-bordeaux.fr.
authors.forename: Corinne
authors.initials: C
authors.lastname: Arpin
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology; D002510:Cephalosporinase; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010957:Plasmids; D011995:Recombination, Genetic; D012093:Replicon; D017422:Sequence Analysis, DNA; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D002442:Ceftazidime; D002510:Cephalosporinase; C103022:beta-lactamase CMY-2; D001618:beta-Lactamases
keywords: IS91 family; IncI1 and IncA/C replicons; insertion sequences; β-lactamases