Effect of Chestnut (Castanea Mollissima Blume) Bur Polyphenol Extract on Shigella dysenteriae: Antibacterial Activity and the Mechanism

Shigella dysenteriae is a highly pathogenic microorganism that can cause human bacillary dysentery by contaminating food and drinking water. This study investigated the antibacterial activity of chestnut bur polyphenol extract (CBPE) on S. dysenteriae and the underlying mechanism. The results showed that the minimum inhibitory concentration (MIC) of CBPE for S. dysenteriae was 0.4 mg/mL, and the minimum bactericidal concentration (MBC) was 1.6 mg/mL. CBPE treatment irreversibly disrupted cell morphology, decreased cell activity, and increased cell membrane permeability, cell membrane depolarization, and cell content leakage of S. dysenteriae, indicating that CBPE has obvious destructive effects on the cell membrane and cell wall of S. dysenteriae. Combined transcriptomic and metabolomics analysis revealed that CBPE inhibits S. dysenteriae by interfering with ABC protein transport, sulfur metabolism, purine metabolism, amino acid metabolism, glycerophospholipid metabolism, and some other pathways. These findings provide a theoretical basis for the prevention and treatment of S. dysenteriae infection with extract from chestnut burs.