Inhibitory effects of 3-(methylthio) propyl isothiocyanate in comparison with benzyl isothiocyanate on Listeria monocytogenes.

The objective of the current study was to investigate the inhibitory effects of benzyl isothiocyanate (BITC) and 3-(methylthio) propyl isothiocyanate (MTPITC) on Listeria monocytogenes (L. monocytogenes). The comparison of the antibacterial potential of these two sulfur-containing flavors was performed by examining the minimum inhibitory concentration (MIC). Moreover, the relative gene expression levels of the major virulence-related factors in L. monocytogenes with co-incubation with BITC (or MTPITC) were measured using real-time quantitative polymerase chain reaction (RT-qPCR) analysis. In addition, the biofilm-forming rate of L. monocytogenes upon exposure to the tested two compounds was determined. Finally, the changes in the bacterial morphology in the presence of BITC (or MTPITC) were detected with the assistance of scanning electron microscopy. The antimicrobial potential of BITC in resistance to L. monocytogenes growth was much stronger than that of MTPITC. Both of the sulfur-containing compounds remarkably suppressed the gene expressions of inlA, hlyA, and prfA. Besides, these two flavors were capable of changing the formation rate of L. monocytogenes biofilms, whereas only slight wrinkles were observed in the bacterial morphology. Overall, both BITC and MTPITC might be promising antibacterial agents to prevent and control L. monocytogenes. [ABSTRACT FROM AUTHOR]