Effects Of Sulfur-containing Flavor On The Expression Of Related Virulence Genes Of Escherichia Coli

In China's food production,it is generally believed that the list of safe food spices contains a variety of sulfur-containing flavor including sulfides and isothiocyanates in improving the flavor of food has an important role.Shiga Toxin Escherichia coli is an enteric pathogen that has certain pathogenicity to humans and animals,especially infants and some young animals.In the study BZITC,PEITC and DADS was selected as material,and the antibacterial activities and the minimal inhibitory concentration of BZITC,PEITC and DADS against non-O157 Shiga toxin-producing Escherichia coli CICC 10670 were determined.The relative activity of AI-2 in bacterial culture supernatant was determined by report strain Vibrio harveyi BB170 under different culture conditions.Real-time quantitative reverse transcriptase-polymerase chain reaction was performed to evaluate the effect of DADS on the virulence factors stx2,eaeA,ehxAand LuxS of E.coli and researching effects of sulfur-containing flavor on the biological activity of Escherichia coli.The result showed that BZITC,PEITC and DADS can the higher inhibitory effect against E.coli.The minimum inhibitory concentration was 62.5 ?mol/L,0.4 mmol/L and 2 mmol/L,respectively.The ability of bacteriostasis was BZITC > PEITC > DADS.Subinhibitory concentrations of sulfur-containing flavor inhibited the expression of stx2,eaeA and ehxA,and a dose-dependent attenuation of stx2,eaeA and ehxA production was observed.AI-2 in Escherichia coli culture supernatant can induce the bioluminescence of Vibrio harnyi BB170.The more sulfur spices added,the lower bioactivity of AI-2,and the sulfur-containing flavor inhibited LuxS expression in a dose dependent manner.From the scanning electron microscope results,the morphology of 1/4 MIC BZITC and PEITC treated Escherichia coli was destroyed,and the bacteria were irregular concave,folded and deformed.After treating 1 h and 4 h with three kinds of sulfur-containing flavor of MIC,the total ATP decreased and the extracellular ATP increased.DADS inhibited the activity of Escherichia coli in a dose-dependent manner under subinhibitory concentration.In conclusion,BZITC,PEITC and DADS have good bacteriostatic effect on Shiga ToxinEscherichia coli,and can inhibit the expression of related virulence genes and quorum sensing gene LuxS at lower concentration,and further explore the inhibition mechanism of sulfur-containing flavor on Escherichia coli.sulfur-containing flavor can be used as a potential natural preservative to prevent food poisoning and prolong the shelf life of food.