We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Microplastic biofilms enhance environmental stress, disinfectant, and antibiotic tolerance of Salmonella enterica serovar typhimurium in simulated fresh vegetable processing systems
Summary
Tiny plastic particles found in food processing systems can form slimy bacterial coatings that help dangerous food poisoning bacteria like Salmonella survive cleaning chemicals and antibiotics better than they normally would. This means contaminated vegetables could be harder to disinfect and the infections they cause could be tougher to treat, making food safety a bigger concern as microplastics become more common in our food supply. Researchers are calling for better ways to control and remove these plastic-bacteria combinations from food production to protect public health.
Microplastics (MPs) are widely found in food supply chains. They act as a stable surface for microorganisms to stick to, which makes it more likely that pathogens will be present. This study aims to investigate the biofilm formation on MPs and evaluate the tolerance of foodborne pathogen Salmonella enterica serovar Typhimurium (ST) to environmental stresses, disinfectants, and antibiotics. The microplastics biofilms (MBs) were constructed on polyethylene MPs by the microbial samples from a vegetable washing sink. Microorganisms can form biofilms on MPs in the lettuce juice-based cultures. The biofilm structure and bacterial community exhibited a succession with the incubation periods. The presence of opportunistic pathogenic genera was identified. ST can successfully colonize preformed MBs, and its environmental stress tolerance to UV radiation, desiccation, and nutrient deprivation was significantly enhanced. Concurrently, mixed-species MBs enhanced the ST tolerance to BAC (Benzalkonium chloride), NaClO and PCMX (Chloroxylenol) disinfectants, and tolerance to ampicillin. These were linked to the upregulation of efflux pumps (acrAB, tolC) and tolerance regulators (phoPQ, oxyR). Genetic analysis revealed a significant upregulation of the ST virulence-associated genes (sipC, csrA, prgJ, sptP, barA, rstA). These findings emphasized the emerging threat of microplastic-biofilm synergistic contamination to food safety, and there is an urgent need to explore the transmission mechanisms and control strategies in the actual food supply chain.