Effect Of Sulfur Containing Spices On The Expression Of Virulence Gene Of Listeria Monocytogenes

Listeria monocytogenes(LM)is a foodborne pathogenic bacteria.The virulence gene inlA,hlyA and prfA play an important role in cell adhesion and invasion.Sulfur-containing flavors is not only a common flavor compound in food,but also has the efficacy of anti-inflammatory.We selects Benzyl isothiocyanate,3-Methylthiopropyl isothiocyanate and Diallyl disulfide as the research object,through the determination of the minimum inhibitory concentration(MIC)to analyze the antibacterial activity of three kinds of flavors.The study analyzed three kinds of sulfur-containing flavors respectively on virulence genes inlA,hlyA and prfA of Listeria monocytogenes by using RT-qPCR.The results showed that virulence genes of inlA,hlyA and prfA were inhibited by three kinds of sulfur-containing flavors,and the inhibition was dose dependent.Quorum sensing plays an important role on food spoilage.AI-2/LuxS is a common signaling pathway of quorum sensing.AI-2 is quorum sensing signal molecule,and LuxS is quorum sensing gene.The effects of three kinds of sulfur containing spices on the secretion of AI-2,the expression of LuxS and formation of biofilm were measured to explore the inhibition mechanism of sulfur containing spices on Listeria monocytogenes.The results showed that benzyl isothiocyanate and diallyl disulfide significantly inhibited the secretion of AI-2,the expression of LuxS and formation of biofilm with the concentration dependent.The total ATP concentration decreased after the treatment of sulfur containing flavor,and extracellular ATP concentration increased.Scanning electron microscopy observation showed that the sulfur containing flavor of benzyl isothiocyanate and 3-Methylthiopropyl isothiocyanate changed the cell surface morphology with the folding phenomenon.In a word,sulfur containing spices combined with three pathways of virulence gene,quorum sensing and biofilm together inhibited the growth of Listeria monocytogenes,but also significantly inhibited the growth of single growth of Listeria monocytogenes in pork fillet.This paper provides a theoretical basis for inhibiting the growth of Listeria monocytogenes by sulfur containing perfume,and providing new ideas for the application of sulfur containing spices in the field of anticorrosion.