title: Genomic islands 1 and 2 play key roles in the evolution of extensively drug-resistant ST235 isolates of Pseudomonas aeruginosa.
abstract: Pseudomonas aeruginosa are noscomially acquired, opportunistic pathogens that pose a major threat to the health of burns patients and the immunocompromised. We sequenced the genomes of P. aeruginosa isolates RNS_PA1, RNS_PA46 and RNS_PAE05, which displayed resistance to almost all frontline antibiotics, including gentamicin, piperacillin, timentin, meropenem, ceftazidime and colistin. We provide evidence that the isolates are representatives of P. aeruginosa sequence type (ST) 235 and carry Tn6162 and Tn6163 in genomic islands 1 (GI1) and 2 (GI2), respectively. GI1 disrupts the endA gene at precisely the same chromosomal location as in P. aeruginosa strain VR-143/97, of unknown ST, creating an identical CA direct repeat. The class 1 integron associated with Tn6163 in GI2 carries a blaGES-5-aacA4-gcuE15-aphA15 cassette array conferring resistance to carbapenems and aminoglycosides. GI2 is flanked by a 12 nt direct repeat motif, abuts a tRNA-gly gene, and encodes proteins with putative roles in integration, conjugative transfer as well as integrative conjugative element-specific proteins. This suggests that GI2 may have evolved from a novel integrative conjugative element. Our data provide further support to the hypothesis that genomic islands play an important role in de novo evolution of multiple antibiotic resistance phenotypes in P. aeruginosa.
authors.affiliation: The ithree institute, Faculty of Science, University of Technology, Sydney, PO Box 123, Broadway, New South Wales 2007, Australia Department of Primary Industries, Elizabeth Macarthur Agriculture Institute, PMB 4008, Camden, New South Wales 2567, Australia piklu.bhattacharya@uts.edu.au.
authors.forename: Piklu
authors.identifier: http://orcid.org/0000-0003-4352-603X
authors.initials: P
authors.lastname: Roy Chowdhury
authors.affiliation: The ithree institute, Faculty of Science, University of Technology, Sydney, PO Box 123, Broadway, New South Wales 2007, Australia.
authors.forename: Martin
authors.initials: M
authors.lastname: Scott
authors.affiliation: The ithree institute, Faculty of Science, University of Technology, Sydney, PO Box 123, Broadway, New South Wales 2007, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Worden
authors.affiliation: Pathology North, The Royal North Shore Hospital, St Leonards, New South Wales 2065, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Huntington
authors.affiliation: Pathology North, The Royal North Shore Hospital, St Leonards, New South Wales 2065, Australia.
authors.forename: Bernard
authors.initials: B
authors.lastname: Hudson
authors.affiliation: SEALS Department of Microbiology, Level 4, Campus Centre Prince of Wales Hospital, Baker Street, Randwick, New South Wales 2031, Australia.
authors.forename: Thomas
authors.initials: T
authors.lastname: Karagiannis
authors.affiliation: The ithree institute, Faculty of Science, University of Technology, Sydney, PO Box 123, Broadway, New South Wales 2007, Australia.
authors.forename: Ian G
authors.initials: IG
authors.lastname: Charles
authors.affiliation: The ithree institute, Faculty of Science, University of Technology, Sydney, PO Box 123, Broadway, New South Wales 2007, Australia steven.djordjevic@uts.edu.au.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Djordjevic
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D024881:Drug Resistance, Bacterial; D019143:Evolution, Molecular; D016680:Genome, Bacterial; D044404:Genomic Islands; D006801:Humans; D010802:Phylogeny; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents
keywords: Pseudomonas aeruginosa; class 1 integron; genomic island; multiple drug resistance; β-lactamases