The potential of Sedum roseum (roseroot) root ethanolic extract and its fractions as an antibacterial agentKunčič, Ajda (Avtor) Smole Možina, Sonja (Mentor) Bucar, Franz (Komentor) pathogenic bacteriaCampylobacter jejuniquorum sensingplant extractsSedum roseumproanthocyanidinsantimicrobial activityDue to the overuse of antibiotics in veterinary and human medicine, antibiotic-resistant strains are developing. Among them is Campylobacter jejuni, a major foodborne pathogen and the leading cause of bacterial gastroenteritis, i.e. campylobacteriosis. In addition to the search of novel antimicrobial agents, the identification of new targets for their action is becoming increasingly important. Plant extracts contain various compounds that could act as antibacterial agents. Sedum roseum has long been used in traditional medicine. Extracts from the underground organs of the plant contain a wide range of biologically active compounds with various pharmacological activities. Most of these extracts are obtained from wild plants, even though harvesting is prohibited in many countries. To preserve the natural sources of S. roseum and to ensure the quality and authenticity of the plant material, domestication and cultivation of the plant seems to be the best solution. In the present work, we used cultivated S. roseum plant material, i.e. “Mattmark” (the first synthetic S. roseum cultivar) and “Rosavine”. Ethanolic extracts of both plant materials were prepared and further fractionated to obtain fractions rich in different compounds or compound groups, i.e. salidroside, rosavins, proanthocyanidins, and/or flavonoids. In this work, for the first time, biologically active compounds or compound groups from S. roseum were separated into different fractions and the antimicrobial activity in relation to chemical composition of the extracts and their fractions was studied. We found that fractions rich in proanthocyanidins had the strongest antimicrobial effect against C. jejuni, with the lowest minimal inhibitory concentrations (MICs), the highest effect on quorum sensing (QS), reduction of motility and adhesion to the polystyrene surfaces. On the other hand, fractions without proanthocyanidins were less effective. We conclude that proanthocyanidins could be one of the crucial compound groups responsible for the antimicrobial activity of S. roseum ethanolic extracts. Since S. roseum is an expensive source of biologically active compounds, it would be beneficial to search for cheaper and more easily available material with similar proanthocyanidin pattern. In addition, further studies are needed to determine exactly how proanthocyanidins act as antibacterial agents against C. jejuni.[A. Kunčič]20212021-07-18 07:15:44Magistrsko delo/naloga128537sl