Antibiofilm Effects of Nanoparticles and Visible Light Illumination Against Listeria monocytogenes

Abstract

Listeria monocytogenes bacteria pose a particular risk to the food industry as the species is known to form biofilm and to survive in a wide range of challenging environmental conditions. L. monocytogenes can cause listeriosis, a serious food-borne disease, and effective and safe antibiofilm materials and sanitary methods for food processing environments are intensively sought. A variety of nanoparticle materials have been recognized as safe to use in food environments, which allows the application of nanomaterials also for food safety purposes. Nanoparticles together with light illumination generate reactive oxygen species which inactivate bacteria by breaking down cell membranes, proteins, and DNA. The main objective of this study was to evaluate the efficacy of nanomaterials and blue light illumination for L. monocytogenes ATCC 7644 biofilm inactivation. Biofilm was allowed to form for 72 h on nanocoated stainless steel and aluminum plates, after which the plates were illuminated. Non-coated control plates were used to evaluate the antibiofilm efficacy of nanocoating. Plate count method was used to evaluate bacteria counts after illumination. Nanocoating did not affect initial biofilm formation compared to the control plates. Biofilm was significantly (p < 0.05) reduced on stainless steel, aluminum, and TiO2-coated aluminum plates after 72-h illumination by 1.9, 3.2, and 5.9 log, respectively. Nanocoating with visible light illumination could be an effective and safe method for enhancing food safety in food processing facilities to control biofilm formation. Evidence of antibiofilm properties of nanomaterials together with visible light illumination is limited; hence, future studies with variable light intensities and nanomaterials are needed.

Critical analysis of methods to determine growth, control and analysis of biofilms for potential non-submerged antibiofilm surfaces and coatings

“…Most materials were categorised as biocide releasing (n = 36) or contact active (n = 32) with fewer antiadhesive (n = 10). Biocide releasing surfaces were predominantly reported as using inorganic nanoparticles and powders such as Ag [ [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] ], Cu [ [34] , [35] , [36] , [37] , [38] ], Ti/TiO 2 [ [39] , [40] , [41] , [42] , [43] , [44] , [45] ], ZnO [ [46] , [47] , [48] ], Cu-Zr-Ni [ 49 ], CeO 2 [ 50 ], Ag/TiO 2 [ 44 , [51] , [52] , [53] ], Fe/Fe 3 O 4 [ 44 , 51 ], TaO x N y [ 54 ] as well as loaded-metal organic frameworks (MOFs) [ 55 ], and antibiotics such as gentamicin [ 56 ]. Contact active surfaces utilized a range of approaches including plasma [ [57] , [58] , [59] , [60] , [61] , [62] , [63] , [64] , [65] , [66] , [67] , [68] , [69] , [70] , [71] , [72] ], amino-acids, polypeptides, enzymes [ [73] , [74] , [75] , …”

Nanotechnology in Food and Plant Science: Challenges and Future Prospects

“…L. monocytogenes is a bacterium that causes listeriosis, a foodborne disease that increases the risk of forming biofilms in the food industry and helps the bacteria to survive in challenging environments. Thus, developing antibiofilm materials for food-processing environments is highly necessary [208]. Nanomaterials with visible light illumination inactivate and reduce the biofilm of L. monocytogenes on TiO 2 -coated aluminum and stainless steel plates after 72-hand illumination, which is suggested as a safe and effective method for use in facilities like food processing for biofilm inhibition [208].…”

“…Thus, developing antibiofilm materials for food-processing environments is highly necessary [208]. Nanomaterials with visible light illumination inactivate and reduce the biofilm of L. monocytogenes on TiO 2 -coated aluminum and stainless steel plates after 72-hand illumination, which is suggested as a safe and effective method for use in facilities like food processing for biofilm inhibition [208]. The combination of Au, Ag, and chitosan NPs at higher concentrations effectively inhibited biofilm growth and decreased metabolic activity (80%) in all the tested strains except for Salmonella enterica infantis; however, nanoparticles were not able to completely remove biofilm mass [209].…”