Abstract

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is one of a major foodborne pathogen concern worldwide. This study aimed to investigate the antibacterial, antibiofilm, and anti-adhesion properties of Piper betle extract against EHEC O157:H7 during storage. The suspected isolates were identified as EHEC O157:H7 through 16S rRNA sequence alignment, showing 100% homology. The extract exhibited antibacterial activity against all isolates, with similar MIC and MBC values as 0.5–1.0 mg/mL. The extract at 1/2×MIC significantly inhibited biofilm formation in all isolates with 66–75% inhibition (P<0.05). Established biofilms were disrupted by 63–76% when treated with Piper betle extract at 8×MIC. Adhered cells on beef were reduced by 3 logs with the extract at 8×MIC within 3 and 6 h at 37°C and 4°C, respectively. A significant reduction in bacterial adhesion on beef was observed when treated with the extract at 8 and 4×MIC during 7-day storage at −18°C. At 7-day storage, beef treated with 8×MIC did not show a significant difference in hardness, cohesiveness, springiness, gumminess, and chewiness of the beef, compared with the control. These findings suggest that Piper betle leaf extract inhibits E. coli O157:H7 biofilms and prevents the bacterial adhesion on beef during storage.