Title: Listeria monocytogenes biofilm formation on silver ion impregnated cutting boards Authors
Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 31, 2008
Publication Date: July 20, 2008
Citation: Berrang, M.E., Frank, J.F., Meinersmann, R.J. 2008. Listeria monocytogenes biofilm formation on silver ion impregnated cutting boards. Poultry Science Association Meeting Abstract. 87(Suppl 1):40. Technical Abstract: Listeria monocytogenes is a human pathogen that can be a member of a biofilm community attached to surfaces in poultry processing plants. When present as a biofilm on product contact surfaces, this organism can effectively cross contaminate fully cooked ready-to-eat meat. Plastic cutting boards can be formulated to include antibacterial agents such as silver ions. In this study we compared the ability of L. monocytogenes to attach and form a biofilm on identical plastic cutting boards manufactured with and without silver ions. Cutting boards were cut into 2 by 2 cm squares and inoculated with a poultry plant isolate of L. monocytogenes known to effectively form biofilms. Inoculation was conducted by submersion in a cell suspension of approximately 108 cells per mL PBS for 2 hours. All pieces were then washed in PBS to remove unattached cells and incubated in dilute (1/10) brain heart infusion broth for 24 hours at 25 C. Un-attached cells were again removed by washing in PBS. The surface was sampled using a pre-moistened sterile cotton swab either immediately after removal of un-attached cells or after a 24 hour dry exposure of attached cells to the board formulation at 25 C. Three replications were conducted with five cutting board squares for each treatment in each replication (n=15). When sampled immediately after washing, similar numbers were recovered from treated and untreated boards: 6.83 and 6.86 log cfu/cm2 respectively. Twenty four hour dry time lessened the density of viable attached L. monocytogenes on both types of cutting boards to the same degree; silver ion impregnated boards had 3.95 log cfu/cm2 while un-treated control boards had 3.97 log cfu/cm2. Under the conditions of these tests, silver ion impregnation did not lessen the ability of L. monocytogenes to form a biofilm on the surface of plastic cutting boards.