Listeria monocytogenes biofilm formation as affected by stainless steel surface topography and coating composition

Biofilm formation on equipment surfaces by pathogens is a significant concern. A study by scientists at the Department of Biomedical and Nutritional Sciences, University of Massachusetts, Lowell, MA, published in Food Control (Vol 130 Dec 2021, 108275), assessed the combined effects of substrate topography and coating composition on L. monocytogenes biofilm formation. Stainless steel 304 with three surface topographies (native finish, #4 commercial brushed finish, and native finish with microfabricated pillars) was evaluated. All were tested either uncoated or coated with one of five FDA-approved food-contact substances (chromium nitride, titanium nitride, Dursan, Ni–P-polytetrafluoroethylene (Ni–P-PTFE), and Lectrofluor 641). Results indicate that surface topography and composition significantly affected fouling resistance. Significant enhancement of resistance to L. monocytogenes fouling was observed on native finish coated by Ni–P-PTFE, which reduced L. monocytogenes by 1.5 Log CFU/cm2. The most significant reductions in L. monocytogenes biofilm formation were obtained with Dursan coated on the native finish (3.4 Log CFU/cm2) and on the micropillar-modified native finish (2.8 Log CFU/cm2).  A new strategy can be applied to create fouling resistance of stainless steel against L. monocytogenes biofilm for improved sanitary design of food processing equipment.  @ https://www.sciencedirect.com/science/article/abs/pii/S0956713521004138#