Listeria monocytogenes adheres to many materials found in food-processing environments.
OBJECTIVE
To investigate the adhesion of Listeria monocytogenes 10403S to 17 different, food-use approved materials representing metals, rubbers and polymers.


RESULTS
Adhesion assays were conducted by placing 'coupons' of the materials in planktonic cultures at 30 degrees C, and then immediately withdrawing them ('short contact') or leaving them submerged in the cultures for 2 h. Adherent cells were recovered by sonication. In the short contact experiments, the logarithm of the mean viable counts ranged from 3.67 +/- 0.43 to 4.78 +/- 0.38. After 2 h contact time, the numbers of adherent cells had increased significantly for all materials with the exception of polypropylene. The highest count (6.33 +/- 0.31) recorded was for stainless steel 405.


CONCLUSIONS
Adhesion to a wide range of materials was time-dependent and characterized by reversible and irreversible stages.


CONCLUSIONS
Adhesion test protocols must account for cell carry-over and cells which are only weakly bound. Material selection may only have a limited role in reducing food contamination by listeria.
Beresford
M R
MR
Department of Chemical Engineering, Loughborough University, Leics, UK.
Andrew
P W
PW
Shama
G
G
D001422:Bacterial Adhesion; D005511:Food Handling / Q000295:instrumentation*; D005516:Food Microbiology; D008089:Listeria monocytogenes / Q000502:physiology*; D008670:Metals; D010969:Plastics; D012408:Rubber
D008670:Metals; D010969:Plastics; D012408:Rubber