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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #352156

Research Project: Characterization and Mitigation of Bacterial Pathogens in the Fresh Produce Production and Processing Continuum

Location: Environmental Microbial & Food Safety Laboratory

Title: Are cruciferous vegetables the key to combat foodborne pathogens infections?

item Patel, Jitu
item Bauchan, Gary

Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: 4/6/2018
Publication Date: 4/25/2018
Citation: Yin, H., Patel, J.R., Mowery, J.D., Bauchan, G.R. 2018. Are cruciferous vegetables the key to combat foodborne pathogens infections?. BARC Poster Day. 53:66.

Interpretive Summary:

Technical Abstract: Escherichia coli O157:H7 and Salmonella spp. are major foodborne pathogens with public health concern that are responsible for 21,100 hospitalizations annually in the United States. Bacterial motility is essential for pathogen colonization in initial phases of infection in the host. Moreover, shiga toxins produced by E. coli O157:H7 are another virulence factors that cause host cell apoptosis and may result in hemorrhagic colitis and hemolytic uremic syndrome in humans. In this study, efficacy of benzyl isothiocyanate (BIT), a cruciferous vegetable-derived compound, for reducing E. coli O157:H7 and Salmonella virulence was investigated. Two strains of E. coli O157:H7 (ATCC 43895 and EDL 933), Salmonella Braenderup (USDA 4559), and Salmonella Tennessee (USDA 4556) were used for antimicrobial studies and virulence inhibition. Sub-inhibitory concentrations (SICs) of BIT were used to evaluate their effects on motility of bacterial pathogens. Briefly, 10 µl of bacterial inoculum (~ 6 log CFU) was added at the center of petri dish containing semi-solid Luria-Bertani agar mixed with BIT at SIC levels. The diameter of the motility zone was measured after 24 h incubation at 37oC. In addition, the effect of BIT at SIC levels on E. coli O157:H7 shiga toxin production was determined by the ELISA procedure. Salmonella Braenderup, the most sensitive bacteria to BIT among the tested pathogens, was chosen for fluorescence-based and transmission electron microscopic (TEM) analyses to determine the mechanism(s) of antimicrobial actions of BIT at the cellular level. The BIT at its SIC levels (0.0125% for Salmonella and 0.015% for E. coli O157:H7) significantly reduced the motility zones of both bacterial pathogens by 96 % to less than 3 mm as compared to 90 mm in untreated control (P<0.05). Shiga toxin production by E. coli O157:H7 was significantly decreased by =32% with BIT treatment at the SIC level. When S. Braenderup was treated with BIT at 0.02% (minimum inhibitory concentration), fluorescent microscopy confirmed the bacterial death via damaged cell membrane and the TEM images revealed the rough surface morphology, shrinkage of Salmonella cells, and leakage of cellular contents. The results of current study collectively suggest that BIT reduces E. coli O157:H7 and Salmonella virulence factors and could be potentially used as an alternative therapeutic treatment for bacterial infections.