Anti-Vibrio parahaemolyticus Mechanism of Hexanal and Its Inhibitory Effect on Biofilm Formation.

Abstract

Vibrio parahaemolyticus (V. parahaemolyticus) is one of the most prevalent foodborne pathogens worldwide. Hexanal is a natural aldehyde derived from plants. In this study, the antimicrobial and antibiofilm activities of hexanal against V. parahaemolyticus were investigated. Hexanal inhibited V. parahaemolyticus growth with a minimum inhibitory concentration (MIC) of 0.4 mg/mL. Hexanal (2 MIC and 4 MIC) increased the leakage of protein and lactic dehydrogenase, reduced intracellular ATP concentration, damaged membrane integrity, and induced abnormal V. parahaemolyticus morphology and ultrastructure. The results of colony enumeration suggested that hexanal exhibited bactericidal action against V. parahaemolyticus in different culture mediums and food systems (Spanish mackerel meat and shrimp paste). At 1/8 MIC and 1/4 MIC, hexanal inhibited biofilm formation of V. parahaemolyticus, as evidenced by crystal violet staining assay and scanning electron microscope (SEM) observation. Moreover, hexanal reduced the levels of extracellular polysaccharide, extracellular protein, and cyclic di-guanosine monophosphate (c-di-GMP) in V. parahaemolyticus. The result of real-time quantitative polymerase chain reaction (RT-qPCR) indicated that hexanal downregulated the expression of genes critical to V. parahaemolyticus biofilm development. This study provides a promising alternative for V. parahaemolyticus control and is conducive to promoting the application of hexanal in the food field.