Purpose: The purpose of this study was to investigate the effect and mechanism of G. biloba extract against Listeria and Salmonella biofilm formation.
Methods: Antibiofilm assay was performed by incubating Listeria and Salmonella isolates from poultry on cell culture slide with or without G. biloba extract. Biofilm was also stained with the LIVE/DEAD BackLight bacterial viability kits and observed by fluorescence microscope. Listeria and Salmonella isolates were inoculated on motility agar with or without G. biloba extract to investigate the influence of G. biloba extract on motility. Effect of G. biloba extract on the growth of Listeria and Salmonella were also evaluated by measuring the optical density of bacterial culture incubated with or without G. biloba extract.
Results: G. biloba extract at 100 μg/ml significantly inhibited initial cell attachment and biofilm formation of Listeria and Salmonella. G. biloba extract reduced the swimming motility of L. innocua and L. welshimeri and the swarming motility of Salmonella Enteritidis and Salmonella Stanley. Swarming and swimming motility inhibition may be one of the mechanisms of the antibiofilm effect of G. biloba extract against some serotypes of Salmonella and Listeria. G. biloba extract also inhibited the growth of Listeria but have no influence on Salmonella.
Significance: The findings of this study provide the basis for the application of G. biloba extract as food additives to promote the quality and safety of poultry products.