title: Antibacterial Activities of Wasabi againstEscherichia coliO157:H7 andStaphylococcus aureus.
abstract: Escherichia coliO157:H7 andStaphylococcus aureusare two of the major pathogens frequently involved in foodborne outbreaks. Control of these pathogens in foods is essential to food safety. It is of great interest in the use of natural antimicrobial compounds present in edible plants to control foodborne pathogens as consumers prefer more natural "green" foods. Allyl isothiocyanate (AITC) is an antimicrobial compound naturally present in wasabi (Japanese horseradish) and several other edible plants. Although the antibacterial effects of pure AITC and wasabi extract (essential oil) against several bacteria have been reported, the antibacterial property of natural wasabi has not been well studied. This study investigated the antibacterial activities of wasabi as well as AITC againstE.coliO157:H7 andS.aureus. Chemical analysis showed that AITC is the major isothiocyanate in wasabi. The AITC concentration in the wasabi powder used in this study was 5.91 ± 0.59 mg/g. The minimum inhibitory concentration (MIC) of wasabi againstE. coliO157:H7 orS. aureuswas 1% (or 10 mg/ml). Wasabi at 4% displayed higher bactericidal activity againstS. aureusthan againstE. coliO157:H7. The MIC of AITC against either pathogen was between 10 and 100 μg/ml. AITC at 500 μg/ml was bactericidal against both pathogens while AITC at 1000 μg/ml eliminatedE. coliO157:H7 much faster thanS. aureus. The results from this study showed that wasabi has strong antibacterial property and has high potential to effectively controlE. coliO157:H7 andS. aureusin foods. The antibacterial property along with its natural green color, unique flavor, and advantage to safeguard foods at the point of ingestion makes wasabi a promising natural edible antibacterial plant. The results from this study may be of significant interest to the food industry as they develop new and safe foods. These results may also stimulate more research to evaluate the antibacterial effect of wasabi against other foodborne pathogens and to explore other edible plants for their antimicrobial properties. To our knowledge, this is the first report on the antibacterial activity of wasabi in its natural form of consumption againstE. coliO157:H7 andS. aureus.
authors.affiliation: Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw GA, USA.
authors.forename: Zhongjing
authors.initials: Z
authors.lastname: Lu
authors.affiliation: Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw GA, USA.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Dockery
authors.affiliation: Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw GA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Crosby
authors.affiliation: Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw GA, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Chavarria
authors.affiliation: Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw GA, USA.
authors.forename: Brett
authors.initials: B
authors.lastname: Patterson
authors.affiliation: Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw GA, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Giedd
keywords: E. coli O157:H7; S. aureus; allyl isothiocyanate; foodborne pathogen; wasabi