Hydrodynamic shear stress to remove Listeria monocytogenes biofilms from stainless steel and polytetrafluoroethylene surfaces
Article first published online: 1 NOV 2012
© 2012 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 114, Issue 1, pages 256–265, January 2013
How to Cite
Gião, M.S. and Keevil, C.W. (2013), Hydrodynamic shear stress to remove Listeria monocytogenes biofilms from stainless steel and polytetrafluoroethylene surfaces. Journal of Applied Microbiology, 114: 256–265. doi: 10.1111/jam.12032
- Issue published online: 12 DEC 2012
- Article first published online: 1 NOV 2012
- Accepted manuscript online: 8 OCT 2012 11:25PM EST
- Manuscript Accepted: 27 SEP 2012
- Manuscript Revised: 13 SEP 2012
- Manuscript Received: 6 AUG 2012
- European Commission within the Seventh Framework Programme. Grant Number: FP7-SME-232037
- Listeria monocytogenes ;
- shear stress;
- stainless steel
To calculate the shear stress needed to remove sessile Listeria monocytogenes cells from stainless steel (SS) and polytetrafluoroethylene (PTFE) surfaces.
Methods and Results
Listeria monocytogenes biofilms were formed on SS and PTFE surfaces. Shear stress was calculated using a radial flow chamber device and cells quantified by staining with 4′,6-diamidino-2-phenylindole. Results showed that shear stress between 24 and 144 N m−2 removed up to 98% of cells from SS surfaces. PTFE presents a very hydrophobic surface, and a significant lower removal (P < 0·05) of only 63% was achieved; moreover, on PTFE discs, detachment of L. monocytogenes biofilms was more efficient at a lower shear stress (between 8·6 and 34 N m−2).
Water flow is more effective in removing L. monocytogenes biofilms from SS surfaces than from PTFE materials.
Significance and Impact of the Study
This work clearly demonstrates that water flow does not have the same efficiency in removing cells from different material surfaces and shows the need to optimize cleaning and sampling procedures by considering the conditions in which cells attach to surfaces and the physicochemistry of the surfaces.