Simulated transmission and decontamination of Listeria monocytogenes biofilms from plastic cutting boards

The presence and persistence of Listeria monocytogenes biofilms on food contact surfaces are often considered as a critical source of cross-contamination of foodstuffs and hence pose a major risk in food safety. This is particularly an issue in numerous countries where knowledge of appropriate food hygiene practices is limited. In this study, the biofilm formation of L. monocytogenes (ATCC 19115) on plastic cutting boards as well as their transmission rates to selected food samples were simulated and evaluated. The effectiveness of the typical household washing practice in biofilm removal from artificially-contaminated plastic cutting boards was also assessed. Crystal violet indicated that L. monocytogenes biofilms on plastic cutting boards mature within 24 h, during which biofilm adhesion was the greatest with 1.62 OD value. The transfer rates of L. monocytogenes from artificially-contaminated plastic cutting board to cabbage (79.27%), chicken fillet (69.88%) and bread (83.25%) during the cutting process were determined. With regards to washing treatment, scrubbing with a commercial dishwashing liquid was shown to be effective at reducing microbial concentrations by 3–6 log CFU/cm2, with virtually all biofilms removed after 5 s of washing. Tap water rinsing on cutting boards was less effective with a mere decrease of 1–2 log CFU/cm2. The findings have provided an insight on the risks associated with the cross-contamination of L. monocytogenes and likely other pathogenic microbes which should be a concern everywhere in the world. Therefore, promoting a better awareness of proper cleaning practices, including the sanitization of cutting boards during food preparations is necessary. •Biofilm of L. monocytogenes can grow on cutting board and transfer to foods.•Scrubbing with dishwasher shown effective on reducing L. monocytogenes count on cutting boards.•Rinsing running water show less effective on reducing L. monocytogenes.•Prolonging treatment time increased log reduction.