Insight into the antibacterial properties of terpinen-4-ol on planktonic growth and biofilm-formation of Vibrio parahaemolyticus

Abstract

Vibrio parahaemolyticus outbreaks emphasize the urgency of highly efficient prevention strategies to control this foodborne pathogen. This study investigated the antibacterial effects of terpinen-4-ol on V. parahaemolyticus RIMD2210633 and explored the underlying mechanism via RNA-seq analysis. The results showed that terpinen-4-ol inhibited V. parahaemolyticus efficiently with minimum inhibitory concentration and minimum bactericidal concentration values at 0.8 μL/mL. Scanning electron microscopy and PI/SYTO 9 staining assay demonstrated that cell morphology and cell membrane integrity were dose-dependently destructed. Additionally, biofilm formation was significantly inhibited according to crystal violet and MTT assay analysis. Notably, terpinen-4-ol showed good inhibitory activity against V. parahaemolyticus on salmon fillets via fumigation at 4 °C. Transcriptional analysis revealed significant downregulation of genes participated in cell wall formation (oppB, oppF), cell membrane integrity, pilus assembly protein, biofilm formation and cell motility (ToxR , LuxR), capsular polysaccharide biosynthesis protein, type IV pilin MshA and mannose-sensitive haemagglutinin type-IV pili (MSHA) biogenesis protein (MshJ, MshJ, MshK, MshL, MshN). The results demonstrated that terpinen-4-ol can efficiently inhibit the growth and pathogenicity of V. parahaemolyticus. With its safety and pleasant odor, terpinen-4-ol can be developed as a natural antibacterial substance to tackle V. parahaemolyticus contamination in food preservation and prevent associated diseases.