Increased antibiotic resistance of pathogenic bacteria and the resistance of bacterial biofilms on the abiotic surfaces in the food industry is a major challenge for ensuring food safety. Current research is focused on alternative components of natural origin as well as on the mechanisms of their action on bacterial cells. At the same time, there is an urgent need for development of fast, specific and cost-effective methods for detection and quantification of pathogenic bacteria in production facilities. In our research, we focused on adhesion of Gram negative C. jejuni and Gram positive L. monocytogenes bacteria. By combining digital PCR and real time PCR methods, we were able to quantify DNA amplicons, which are proportional to the quantity of cells that adhered on polystyrene surface. Furthermore, we evaluated the anti-adhesive effect of natural compounds, such as carvacrol, thymol, α-pinene and epigallocatechin gallate (EGCG). The addition of carvacrol, thymol and EGCG individually in subinhibitory concentration showed more than 90% reduction of adhesion. Moreover, more than 99% adhesion inhibiton was shown when combining the above three compounds and all four of them. As seen, the natural compounds present an efficient alternative strategy in prevention of bacterial adhesion and consequent biofilm formation.
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