Escherichia coli O157:H7 has caused many foodborne disease outbreaks and resulted in unimaginable economic losses. With the evolution of food consumption, people prefer natural preservatives. In this study, the natural agent harmane exhibited potential activity against E. coli O157:H7 (MIC = 64 μg/mL). It exhibited bacteriostatic mode at 1 X and 2 X MIC treatment, and bactericidal mode at 4 X MIC treatment. Moreover, it showed good in vitro stability in sheep plasma, low in vitro hemolysis and no in vivo acute toxicity with LD > 50 mg/kg. Moreover, harmane significantly decreased the colony number of E. coli O157:H7 in fresh-cut lettuce samples after 5 days of storage without affecting appearance. The mechanism study elucidated that harmane significantly decomposed the mature biofilm by reducing exopolysaccharide contents, and killed the viable bacterial cells in biofilm. The cell wall was damaged by harmane via interacting with peptidoglycan. Fluorescent staining and intracellular macromolecular leakage assays showed that irreversible destruction to membrane permeability and integrity. When entering the cell, harmane could defeat the redox balance, suppress metabolic activity and target to ribosome. These findings not only revealed the application potential of harmane as new natural preservative, but also preliminarily elucidated the multi-target mechanism, providing a new strategy for controlling E. coli O157:H7 in the food industry.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2025.111084 | DOI Listing |
Int J Biol Macromol
October 2024
Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Shahrekord University, Shahrekord, Iran.
Foodborne Pathog Dis
July 2024
Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Concepción, Chile.
Zhonghua Liu Xing Bing Xue Za Zhi
August 2022
Department of Epidemiology, College of Public Health, Zhengzhou University, Zhengzhou 450001, China.
To evaluate the typing and clinical application effect based on clustered regularly interspaced short palindromic repeats (CRISPRs), serotype, and Multilocus Sequence Typing (MLST). The spacers, serotype and sequence type (ST) were obtained with CRISPRsFinder, SeroTypeFinder and MLST. PCR was used to amplify the CRISPRs, and the spacers were used to predict serotype and ST, then comparing with the serotype and ST.
View Article and Find Full Text PDFRSC Adv
January 2022
College of Artificial Intelligence, Guangdong Mechanical & Electrical Polytechnic Guangzhou 510550 P. R. China +86-20-36552429 +86-20-36552429.
Rapid measurement of waterborne bacterial viability is crucial for ensuring the safety of public health. Herein, we proposed a colorimetric assay for rapid measurement of waterborne bacterial viability based on a difunctional gold nanoprobe (dGNP). This versatile dGNP is composed of bacteria recognizing parts and signal indicating parts, and can generate color signals while recognizing bacterial suspensions of different viabilities.
View Article and Find Full Text PDFCan J Microbiol
September 2021
Department of Food Engineering, Beytepe, Hacettepe University, Ankara, Turkey.
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