title: Carbapenemase-producing Pseudomonas aeruginosa from central Greece: molecular epidemiology and genetic analysis of class I integrons.
abstract: BACKGROUND
  Multidrug-resistant Pseudomonas aeruginosa is a serious challenge for antimicrobial therapy of nosocomial infections, as it possesses several mechanisms of antimicrobial resistance. In Central Greece, a sudden increase of infections caused by carbapenem-resistant P. aeruginosa was observed during 2011, indicating the need for further analysis.
  
  
  METHODS
  Five-hundred and sixty-eight P. aeruginosa isolates were collected consecutively during an 8-month period in 2011 from inpatients treated in three hospitals in the Thessaly region (1,000,000 habitants) of Greece. Carbapenem-resistant P. aeruginosa (n = 284) were characterized by antimicrobial susceptibility testing and β-lactamase content, and the genetic relatedness of carbapenemase-producing isolates was assessed by BOX-PCR, multilocus sequence typing, and eBURST analysis. Mapping of the class I integrons of Verona integron-encoded metallo-β-lactamase (VIM)-carrying isolates was also performed, and clinical data of the VIM producers were reviewed.
  
  
  RESULTS
  Eighty (14.1%) out of the 568 P. aeruginosa isolates recovered from clinical specimens were VIM producers. Multilocus sequence typing revealed high prevalence of the international clones ST111 and ST235 among blaVIM-2- and blaVIM-4-positive isolates, respectively. blaVIM-17 was identified in an isolate of a novel sequence type (ST1457). blaVIM gene cassettes were carried by five distinct class I integrons, including two novel ones.
  
  
  CONCLUSIONS
  Since the first report of VIM-producing P. aeruginosa in 2000, this microorganism still remains among the most prevalent multidrug resistant pathogens in Greece. The spread of VIM-producers belonging to the most common international clones (ST111 and ST235), the spread of integrons of divergent structures, and the emergence of novel integrons underscore their ongoing evolution.
authors.forename: Apostolos
authors.initials: A
authors.lastname: Liakopoulos
authors.forename: Angeliki
authors.initials: A
authors.lastname: Mavroidi
authors.forename: Efstathios A
authors.initials: EA
authors.lastname: Katsifas
authors.forename: Alexandros
authors.initials: A
authors.lastname: Theodosiou
authors.forename: Amalia D
authors.initials: AD
authors.lastname: Karagouni
authors.forename: Vivi
authors.initials: V
authors.lastname: Miriagou
authors.affiliation: Department of Microbiology, University Hospital of Larissa, Larissa, Greece. petinaki@med.uth.gr.
authors.forename: Efthymia
authors.initials: E
authors.lastname: Petinaki
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D015780:Carbapenems / Q000494:pharmacology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D006115:Greece / Q000453:epidemiology; D006801:Humans; D032023:Integrons; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D011552:Pseudomonas Infections / Q000453:epidemiology / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015780:Carbapenems; D004269:DNA, Bacterial; D001618:beta-Lactamases; C063912:carbapenemase