Evaluation of the Antimicrobial Activity of Gut Catabolites of Quercetin 4'-glucoside on Listeria monocytogenes and Their Effects on Membrane Integrity and Biofilm Formation.

Abstract

Aims: Listeria (L.) monocytogenes is the well-known foodborne pathogen that requires critical control in the human body. 3-hydroxyphenylacetic acid (OPAC) and 3,4-dihydroxyphenylacetic acid are gut catabolites of quercetin 4'-glucoside in onion, their antibacterial effects would help to control the risk of L. monocytogenes. Here, we investigate their antibacterial activity, action at the transcript level and effects on membrane and biofilm to better control L. monocytogenes.

Methods and results: RNA-Seq data revealed that the OPAC and DOPAC treatments to L. monocytogenes led to the identification of enormously differently expressed genes in cellular components (membrane) and phosphotransferase system pathway at their 1/2 MIC (7.805 mM⸱L-1). DOPAC exhibited more obviously damaged in membrane (max 33.94%) and biofilm (max 88.2%) than that of OPAC which may be related to their different effects on cell hydrophobicity, mobility and morphology.

Conclusions: These findings provided a credibly inhibitory mechanism of OPAC and DOPAC on L. monocytogenes, offering the theoretical basis for potential applications on the other kinds of phenolic acids that would possess similar structures in food industry.