The in vitro antibiofilm activity of selected culinary herbs and medicinal plants against Listeria monocytogenes

Abstract

Aims: The antibiofilm activity of extracts obtained from selected herbs, spices, beverages and commercially important medicinal plants was investigated on Listeria monocytogenes. Methods and Results: The growth and development of the biofilm was assessed using the crystal violet (CV) assay. The respiratory activity was assessed using the 2, 3‐bis [2‐methyloxy‐4‐nitro‐5‐sulfophenyl]‐2H‐tetrazolium‐5‐carboxanilide (XTT) reduction assay. The majority of extracts tested prevented cell adhesion to the polyvinyl chloride (PVC) surface. Seven of the 15 extracts reduced biofilm adhesion of both the clinical and the type strains by at least 50%. In contrast, inhibition of a preformed biofilm was more difficult to achieve, with only three extracts (Rosmarinus officinalis, Mentha piperita and Melaleuca alternifolia) inhibiting the growth of both strains by at least 50%. Conclusions: Although most extracts were able to reduce initial cell attachment, inhibition of growth in a preformed biofilm was more difficult to achieve. Significance and Impact of the Study: The ability to reduce biofilm biomass as shown by several plant extracts warrants further investigation to explore the use of natural products in antibiofilm adhesion.

Anti-biofilm activity ofSalvadora persicaon cariogenic isolates ofStreptococcus mutans:in vitroand molecular docking studies

“…The lifecycle of biofilms of the S. mutans isolate has revealed its oral adaptation to recurrently exposed stresses such as extreme shortage or excess of nutrients, low pH, high osmolarity, oxidation, and consumption of antimicrobial agents or antibiotics (Donlan and Costerton 2002). Investigations on antibacterial plants and their active constituents have focused entirely on planktonic bacteria with little emphasis on the more resistant and difficult to control biofilm forms (Sandasi et al 2010). The present study highlighted not only the bioactive phytochemicals of S. persica but also revealed their importance in cleansing teeth through mechanical and antibacterial actions.…”

“…The increased dissolution of active constituents in methanol indicated the presence of more phenolic compounds and extraction due to their release from cell wall-bound polyphenols by the lowpolarity methanol (Lapornik et al 2005). Isolation and identification of constituents that exhibit anti-biofilm properties may be important alternatives in the control of biofilms (Sandasi et al 2010). GC-MS of S. persica methanol extracts revealed a large number of phytochemicals comprising many groups (although most were phenolic).…”

Chemical composition, antibacterial and antifungal activities of Saudi Arabian Mentha longifolia L. essential oil

“…The essential oils of Mentha longifolia L. (M. longifolia) have been extensively investigated, as evident in a large number of studies focusing on their antiviral, antimicrobial, antifungal [10][11][12], antibiofilm formation [13][14][15], radioprotective [16,17], antioedema, analgesic and antioxidant properties [13].…”

Small-Molecule Modulators of Listeria monocytogenes Biofilm Development

“…In the presence of sodium levulinate, sodium lactate, or fatty acids, the growth of L. monocytogenes on ready-to-eat food was inhibited (46,53). In addition, thyme essential oils, culinary herb extracts, or highmolecular-weight extracellular DNA can prevent adhesion of cells to a surface (21,38,44). Low concentrations of EDTA reduced initial cell attachment of L. monocytogenes to polyvinyl chloride without affecting planktonic cell density and inhibited cell-to-cell interactions (12).…”