Antibiofilm effect and mechanism of protocatechuic aldehyde against .

This study investigated the effect of protocatechuic aldehyde (PCA) on biofilm formation and its effects on gene expression. Crystal violet assay, metabolic activity assay, and fluorescence experiments were used to evaluate the antibiofilm activities of PCA and to reveal its possible antibiofilm mechanisms using transcriptomic analysis. The results indicated that the minimum antibacterial concentration of PCA against was 300 μg/mL. PCA (9.375 μg/mL) inhibited biofilm generation and adhesion of the mature biofilm. PCA (75 μg/mL) significantly reduced the metabolic viability of , reduced polysaccharide production, and inhibited cell surface flagella-mediated swimming and aggregation phenotypes. Meanwhile, transcriptome analysis showed that the key genes of expressed under PCA (75 μg/mL) inhibition were mainly related to biofilm formation (, , , and ), polysaccharide production and adhesion (, , and ), and motility (, , and ). By regulating these key genes, PCA reduced biofilm formation, suppressed polysaccharide production and transport, and prevented the adhesion of , thereby reducing the virulence of . This study demonstrated that protocatechuic aldehyde can be used to control biofilm to ensure food safety.