Antimicrobial and biofilm inhibition effects of p-anisaldehyde against Vibrio parahaemolyticus

Vibrio parahaemolyticus is a food-borne bacterial pathogen that seriously threatens the safety of seafood and human health. Biofilm formation is an important cause of pathogenicity and effective natural antibiofilm substances are urgently needed. Herein, we investigated the antimicrobial and antibiofilm effects of p-anisaldehyde (PAA) from Pimpinella anisum L. against V. parahaemolyticus, along with its application on salmon. The minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PAA against V. parahaemolyticus was 2 μL/mL. PAA inhibited the growth, motility and adhesion of V. parahaemolyticus in a dose-dependent manner. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) confirmed that cell membrane integrity was disrupted and the ultrastructure of cells was damaged. Transcriptome analysis showed that treatment with PAA resulted in significant differences in the expression of 2415 genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that differentially expressed genes related to biofilm formation, flagella mobility and quorum sensing (QS) were significantly altered in V. parahaemolyticus. Notably, PAA could also inhibit V. parahaemolyticus in salmon via fumigation, suggesting its potential application in food preservation. This study identified PAA as a potential natural antimicrobial agent to inhibit biofilm formation of V. parahaemolyticus and thereby protect salmon against infection.