| dc.description.abstract | Development of bacterial resistance to antibiotics during long term use and poor responsiveness to therapy are seen in daily practice. It can be hypothesized that the non-response tot treatment is related to biofilm formation. The formation of biofilms greatly limits the efficacy of treatment with antibiotics. Therefore there is a high interest in the development of antibiofilm compounds. For the formation of biofilms bacteria are dependent on a form of cell-to-cell communication called quorum sensing. This research focuses on the possible inhibition of quorum sensing by rosmarinic acid (RA). RA is a phenolic compound that is naturally found in plants, such as Rosmarinus officinalis, Melissa officinalis, Origanum vulgare, Salvia officinalis, Thymus vulgaris and Mentha piperita. A rapid biofilm formation assay with Staphylococcus Aureus was used as an indicator of the effect of RA on quorum sensing. Also a dilution broth assay with S. aureus was performed with RA to investigate the antibiotic effects of RA. Three different cytotoxicity assays were performed on murine intestinal cells in order to get an indication of the safety of the use of RA for oral application in vivo. There was no MIC value found for RA in the dilution broth assay. A slight cytotoxicity was measured at RA concentrations above 0,8881 µmol/ml. No inhibition of biofilm formation was found for RA at concentrations of 320 µg/ml and lower. There is an indication that RA might inhibit biofilm formation at higher concentrations. More research into the effects of RA is necessary before it can be applied in veterinary practice. | |
