Biofilm formation of food borne pathogens on plastic surfaces: An in situ and ex situ evaluation

Plastics have become an integral part of modern life, and their improper use and disposal are contributing to global environmental concerns. An emerging and less explored risk is the ability of plastics to act as novel substrates for clinically relevant human pathogens. This study investigated the biofilm-forming ability of food-borne pathogens on plastic polymers under both in situ and ex situ conditions. Plastic samples were characterized using FTIR spectroscopy, and the biofilm-forming potential of human enteric bacteria on polymers was evaluated under varying temperature and salinity regimes. Biofilm development was examined using scanning electron microscopy and quantitatively assessed, with statistical significance determined by two-way ANOVA (p ≤ 0.05). The results demonstrated that enteric bacteria readily colonized polyethylene (PE) surfaces, forming dense biofilms even on polymers incubated in sterile water. Among the tested pathogens, Escherichia coli exhibited the highest biofilm-forming capacity on PE plastics. These findings indicate that plastic debris can function as an effective substrate for biofilm formation by food-borne pathogens, highlighting the potential public health and environmental risks associated with plastic pollution. The study underscores the importance of responsible plastic use and improved waste management strategies to mitigate threats to both human and marine ecosystems.