title: Improved recovery of Listeria monocytogenes from stainless steel and polytetrafluoroethylene surfaces using air/water ablation.
abstract: OBJECTIVE
  To develop a gentle ablation technique to recover Listeria monocytogenes biofilms from stainless steel (SS) and polytetrafluoroethylene (PTFE) surfaces by using compressed air and water injection.
  
  
  RESULTS
  Biofilms were grown for 4, 24 and 48 h or 7 days and a compressed air and water flow at 2, 3 and 4 bars was applied for cell removal. Collected cells were quantified for total/dead by staining with SYTO 9/PI double staining and cultivable populations were determined by plating onto brain heart infusion (BHI) agar, while coupon surfaces also were stained with DAPI to quantify in situ the remaining cells. The recovery efficiency was compared to that of conventional swabbing. Results showed that the air/water ablation is able to collect up to 98·6% of cells from SS surfaces while swabbing only recovered 11·2% of biofilm. Moreover, air/water ablation recovered 99·9% of cells from PTFE surfaces.
  
  
  CONCLUSIONS
  The high recovery rate achieved by this technique, along with the fact that cells were able to retain membrane integrity and cultivability, indicate that this device is suitable for the gentle recovery of viable L. monocytogenes biofilm cells.
  
  
  CONCLUSIONS
  This work presents a highly efficient technique to remove, collect and quantify L. monocytogenes from surfaces commonly used in the food industry, which can thus serve as an important aid in verifying cleaning and sanitation as well as in reducing the likelihood of cross-contamination events.
authors.affiliation: Centre for Biological Sciences, University of Southampton, Southampton, UK.
authors.forename: M S
authors.initials: MS
authors.lastname: Gião
authors.affiliation: 40-30, Parc Technologique des Fontaines, Chemin des Franques, Bernin, France.
authors.forename: S
authors.initials: S
authors.lastname: Blanc
authors.affiliation: Ainia, Parque Tecnólogico de Valencia, Valencia, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Porta
authors.affiliation: Ainia, Parque Tecnólogico de Valencia, Valencia, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Belenguer
authors.affiliation: Centre for Biological Sciences, University of Southampton, Southampton, UK.
authors.forename: C W
authors.initials: CW
authors.lastname: Keevil
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods*; D018441:Biofilms; D005506:Food Contamination / Q000032:analysis; D005525:Food-Processing Industry / Q000295:instrumentation; D008089:Listeria monocytogenes / Q000254:growth & development* / Q000302:isolation & purification / Q000502:physiology; D011138:Polytetrafluoroethylene / Q000032:analysis; D013193:Stainless Steel / Q000032:analysis
chemical_list: D013193:Stainless Steel; D011138:Polytetrafluoroethylene
keywords: Listeria monocytogenes; air/water ablation; biofilms recovery; polytetrafluoroethylene surfaces; stainless steel surfaces