Effect of Mentha viridis L. Extracts on Pathogenic Bacteria Adhesion

Micro-organisms do not always exist in planctonic forms (single cells or small groups). To survive, especially in limiting media, they may adhere to inert or living surfaces. This enables them to multiply within a community protected by an extracellular matrix, thus forming a biofilm which protects them from antimicrobials especially antibiotics. In this paper, the aim of this study was to investigate autoaggregation, co-aggragation, surface hydrophobicity and exopolysaccharides production of different pathogenic bacteria treated with methanolic, hydro-methanolic and aqueous extract of Mentha viridis collected in El Bayadh (South West of Algeria). The qualitative analysis revealed the presence of polyphenols and flavonoids, which were confirmed-by-quantitative-analysis. All extracts showed an antibacterial activity (antiadhesiveness).The percentage of autoaggregation, coaggregation decreased in presence of extract comparing to control. E.coli was hydrophobic while the others hydrophilic. The amount of exopolysaccharides (EPS) produces by bacteria decreased considerably with all extracts comparatively to control (without extracts).