title: Clonal relatedness and conserved integron structures in epidemiologically unrelated Pseudomonas aeruginosa strains producing the VIM-1 metallo-{beta}-lactamase from different Italian hospitals.
abstract: Three epidemiologically independent Pseudomonas aeruginosa isolates, representative of the first VIM-1 metallo-beta-lactamase producers detected at three different hospitals in northern Italy, were investigated to determine their genomic relatedness and to compare the structures of the genetic supports for the VIM-1 determinants. The three isolates, all of serotype O11, appeared to be clonally related according to the results of genotyping by macrorestriction analysis of genomic DNA by pulsed-field gel electrophoresis and random amplification of polymorphic DNA. Investigation of the genetic support for the bla(VIM-1) determinant revealed that it was carried on identical or almost identical integrons (named In70.2 and In70.3) located within a conserved genomic context. The integrons were structurally related to In70 and In110, two plasmid-borne bla(VIM-1)-containing integrons from Achromobacter xylosoxidans and Pseudomonas putida isolates, respectively, from the same geographic area (northern Italy) and were found to be inserted close to the res site of a Tn5051-like transposon, different from any of those described previously, that was apparently carried on the bacterial chromosome. The present findings suggest that the three VIM-1-producing isolates are members of the same clonal complex which have been spreading in hospitals in northern Italy since the late 1990s and point to a common ancestry of their bla(VIM-1)-containing integrons.
authors.affiliation: Dipartimento di Biologia Molecolare, Sezione di Microbiologia, Università di Siena, Policlinico "Le Scotte", 53100 Siena, Italy.
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Riccio
authors.forename: Lucia
authors.initials: L
authors.lastname: Pallecchi
authors.forename: Jean-Denis
authors.initials: JD
authors.lastname: Docquier
authors.forename: Stefania
authors.initials: S
authors.lastname: Cresti
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Catania
authors.forename: Laura
authors.initials: L
authors.lastname: Pagani
authors.forename: Cristina
authors.initials: C
authors.lastname: Lagatolla
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Cornaglia
authors.forename: Roberta
authors.initials: R
authors.lastname: Fontana
authors.forename: Gian Maria
authors.initials: GM
authors.lastname: Rossolini
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001483:Base Sequence; D017124:Conserved Sequence; D016521:Electrophoresis, Gel, Pulsed-Field; D006785:Hospitals, University; D006801:Humans; D032023:Integrons / Q000235:genetics*; D007558:Italy / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D011552:Pseudomonas Infections / Q000453:epidemiology* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; C417264:VIM-1 metallo-beta-lactamase; D001618:beta-Lactamases