Anti bacterial and Anti Quorum Sensing Properties of Dionysia Revolute Boiss against Secondary Bacterial Infections of COVID 19 Patients; An in vitro Study

Background and aim: today, the use of traditional plant compounds to kill or interfere with their quorum sensing (qs) mechanisms is considered as an alternative approach to control secondary bacterial infections during or after a viral infection. in this study, anti-bacterial and anti-quorum sensing effect of dionysia revolute boiss against five secondary bacterial infections of covid-19 patients were evaluated.materials and methods: extraction of the plant compounds was carried out using n-hexane, methanol, and 96% ethanol mixed solvent. bacterial samples were collected from respiratory tract fluids among covid-19 patients and recognized with api kits. antibacterial activity of the herbal extract was assessed by disc diffusion method as proposed by the clinical laboratory standards institute (clsl, 2015). hence, anti-qs activities of this herbal extract at the sub-minimum inhibitory concentration (mic) were assessed by violacein quantification assay in chromobacterium violaceum cv026 biosensor strains in vitro.results: as it has been indicated in the results section, a plant extract from 50 to 0.39 mg/ml exposed their antibacterial impacts via hindering the bacterial growth in comparison with controls and exhibited anti-qs activities via decreasing the violacein formation in c. violaceum cv026 biosensor strain at sub-mic concentrations (3.1 to 0.39 mg/ml) in vitro.conclusion : our study showed that the antimicrobial activities of dionysia revolute boiss could be due to their anti-qs properties. therefore, this medicinal plant either as a stand-alone treatment or in combination with antibiotics could be used as an efficient choice for curing secondary bacterial infections.