The effect of phytochemicals on the signaling molecules of the "Quorum Sensing" system in bacteria

Abstract

The system of cell–cell communication of bacteria is necessary for bacteria to coordinate interactions between themselves and with higher organisms. It regulates a number of properties of microorganisms, including pathogenicity and resistance to antibiotics. Therefore, the study of methods of influencing this system seems to be critically important. A special place in this context is occupied by plants and their metabolites (phytochemicals), which have the ability to inhibit the system of cell–cell communication in bacterial communities. Studies using bovine ruminal fluid can lead to an understanding of how this process is regulated in the rumen. The aim of the work was to evaluate the possible effect of phytochemicals (trans-cinnamaldehyde, quercetin, coumarin, vanillin) on the signal molecules of the "Quorum sensing" system of bacteria (for example, the recombinant luminescent biosensor Escherichia coli pAL103) in the presence of ruminal fluid of cattle. It was found that the scar fluid at a concentration of 12,5 % did not affect the level of biosensor luminescence. For all studied phytochemicals, the ability to inhibit the process of cell–cell communication (by binding signal molecules) was recorded, which was expressed in a significant decrease in the bioluminescence of the E. coli pAL103 test strain. At the same time, the most pronounced change in the level of biosensor luminescence was detected under the combined action of rumen fluid with trans-cinnamaldehyde, and the smallest change was detected under the influence of ruminal fluid with coumarin, vanillin, or quercetin. The results obtained expand the understanding of the action of phytochemicals, which can be in demand when compiling the diet of cattle and will allow controlling the activity of pathogenic bacteria in animals by suppressing the system of cell–cell communication.