title: Preliminary feasibility and modelling of a liquid matrix Dictyostelium discoideum virulence assay for Pseudomonas aeruginosa.
abstract: OBJECTIVE
  To develop and determine the feasibility of using a liquid matrix adaptation of the Dictyostelium discoideum bacterial virulence assay by testing on well-characterised clinical and environmental isolates of Pseudomonas aeruginosa.
  
  
  METHODS
  Axenic AX2 D. discoideum were co-cultured with clinical and environmental isolates of P. aeruginosa in costar 24-well tissue culture plates for 24 h. A P. aeruginosa PAO1 positive control was tested in biological quintuplicate. Wells were then inspected using an inverted microscope and the degree of cytotoxic changes (sparse growth compared to control combined with rounding of cells and cytoplasmic shrinkage) on the D. discoideum cells was observed. A Klebsiella aerogenes negative control was included with each assay series.
  
  
  RESULTS
  Sixty-five clinical and 20 environmental P. aeruginosa isolates were tested in the model. Cystic fibrosis respiratory isolates were found to be significantly (P < 0.05) less cytotoxic than P. aeruginosa from other sources. Limitations attached to the funding of this paper did not allow validation against previously employed models or animal models.
  
  
  CONCLUSIONS
  A liquid matrix D. discoideum model for the analysis of P. aeruginosa virulence in a eukaryotic host is feasible, but further validation of the model is required before it may be employed in routine setting.
authors.affiliation: a School of Medicine , University of Tasmania , Hobart , Australia.|b Faculty of Science, Medicine and Health , University of Wollongong , Wollongong , Australia.
authors.forename: Alan Charles
authors.initials: AC
authors.lastname: Champion
authors.affiliation: a School of Medicine , University of Tasmania , Hobart , Australia.
authors.forename: Neralee Kaye
authors.initials: NK
authors.lastname: Houston
authors.affiliation: c School of Medical & Applied Sciences , Central Queensland University , Rockhampton , Australia.
authors.forename: Richard Stewart
authors.initials: RS
authors.lastname: Bradbury
authors.affiliation: d QIMR Berghofer Medical Research Institute , Herston , Australia.
authors.forename: David William Edward Cochrane
authors.initials: DW
authors.lastname: Reid
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods*; D004023:Dictyostelium / Q000254:growth & development* / Q000382:microbiology*; D004195:Disease Models, Animal; D005240:Feasibility Studies; D010865:Pilot Projects; D011550:Pseudomonas aeruginosa / Q000145:classification* / Q000302:isolation & purification / Q000472:pathogenicity*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Dictyostelium discoideum; Pseudomonas aeruginosa; virulence model