title: Molecular epidemiology of Pseudomonas aeruginosa bloodstream infection isolates in a non-outbreak setting.
abstract: OBJECTIVE
  The molecular epidemiology of Pseudomonas aeruginosa bloodstream infection (BSI) isolates has received limited attention. This study aims to characterize the molecular relationship of P. aeruginosa BSI isolates in the non-outbreak setting at a single tertiary healthcare facility.
  
  
  METHODS
  P. aeruginosa BSI isolates from patients who were admitted to the Royal Brisbane and Women's Hospital over a 13 month period from November 2009 were identified retrospectively from the Pathology Queensland Clinical and Scientific Information System. The isolates were typed by the iPLEX MassARRAY matrix assisted lazer desorption/isonisation time of flight (MALDI-TOF) MS genotyping. The DiversiLab automated rapid strain typing platform (bioMérieux) was used to assess the genotypic relationships between study isolates that showed indistinguishable iPLEX20SNP profiles. Clinical data was also collected retrospectively from patient notes.
  
  
  RESULTS
  Fifty-three P. aeruginosa BSI episodes were available for study. Thirty-five different clones or clonal complexes were identified by the iPLEX MassARRAY MALDI-TOF MS genotyping. Seventeen BSI isolates with indistinguishable iPLEX20SNP profiles underwent further DiversiLab genotyping and were found to belong to a further 13 different genotypes. There was no relationship between clonality and acquisition type, source of infection or length of stay in the setting of hospital-acquired infection.
  
  
  CONCLUSIONS
  The non-clonal population structure suggests that there is ongoing environmental exposure of inpatients to P. aeruginosa. In clinical areas dealing with at-risk patients, routine attention to mechanism of environmental colonization is important and should be addressed even in the non-outbreak setting.
authors.affiliation: UQ Centre for Clinical Research, The University of Queensland, Brisbane, Australia.
authors.forename: Kate L
authors.initials: KL
authors.lastname: McCarthy
authors.affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia.|Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK.|Child Health Research Centre, The University of Queensland, Brisbane, Australia.
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Kidd
authors.affiliation: UQ Centre for Clinical Research, The University of Queensland, Brisbane, Australia.
authors.forename: David L
authors.initials: DL
authors.lastname: Paterson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000097:blood / Q000453:epidemiology*; D015373:Bacterial Typing Techniques; D003001:Cloning, Molecular; D003428:Cross Infection / Q000097:blood / Q000453:epidemiology* / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D005260:Female; D060005:Genotyping Techniques; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D011552:Pseudomonas Infections / Q000097:blood / Q000453:epidemiology*; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000302:isolation & purification; D011793:Queensland / Q000453:epidemiology; D012189:Retrospective Studies; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial