Antibiofilm activity of coriander (Coriander sativum L.) grown in Argentina against food contaminants and human pathogenic bacteria

Bacterial spoilage of food and other infections are a coordinated mechanism controlled by quorum sensing (QS), which regulate the expression of virulence factors, such as biofilm. The antimicrobial, antibiofilm, anti-QS and anti-swarming properties of hexane (HE), chloroform (CE), ethyl acetate (EAE), methanolic (ME) and total methanolic (TME) extracts of coriander grown in Argentina were investigated. In vivo extracts toxicity using Galleria mellonella L. model and chemical composition (GC-MS) were also assessed. The antibiofilm activity of polystyrene surfaces coated with the most active extracts was evaluated. At non-inhibitory growth concentrations, extracts showed a strong antibiofilm capacity and a slight anti-swarming and anti-QS activities. Likewise, none of the extracts were toxic up to 2500 mg/kg. For all bacteria tested (Escherichia coll., Salmonella enterica, Pseudomonas aeruginosa and Staphylococcus aureus), HE and CE of coriander were the most active extracts for inhibiting the formation and the metabolic activity of biofilm, especially for S. aureus. The anti-staphylococcal biofilm activity was confirmed by fluorescence and scanning electron microscopy. Extract-coated polystyrene surfaces decreased bacterial adhesion and subsequent biofilm formation, even after washing. A total of 11 and 14 chemical compounds were identified from the HE and CE, respectively, being oleic acid the main compound in both extracts. Particularly, the strong inhibitory activity of coriander HE against S. aureus biofilms is emphasizing. These results suggest the possible application of these extracts either as an antibiofilm agent or by generating anti-adherent surfaces in the food industry and in the clinical area.