Impact of Quercetin against Salmonella Typhimurium Biofilm Formation on Food–Contact Surfaces and Molecular Mechanism Pattern

Abstract

Quercetin is an active nutraceutical element that is found in a variety of foods, vegetables, fruits, and other products. Due to its antioxidant properties, quercetin is a flexible functional food that has broad protective effects against a wide range of infectious and degenerative disorders. As a result, research is required on food-contact surfaces (rubber (R) and hand gloves (HG)) that can lead to cross-contamination. In this investigation, the inhibitory effects of quercetin, an antioxidant and antibacterial molecule, were investigated at sub-MIC (125; 1/2, 62.5; 1/4, and 31.25; 1/8 MIC, μg/mL) against Salmonella Typhimurium on surfaces. When quercetin (0–125 μg/mL) was observed on R and HG surfaces, the inhibitory effects were 0.09–2.49 and 0.20–2.43 log CFU/cm2, respectively (p < 0.05). The results were confirmed by field emission scanning electron microscopy (FE-SEM), because quercetin inhibited the biofilms by disturbing cell-to-cell connections and inducing cell lysis, resulting in the loss of normal cell morphology, and the motility (swimming and swarming) was significantly different at 1/4 and 1/2 MIC compared to the control. Quercetin significantly (p < 0.05) suppressed the expression levels of virulence and stress response (rpoS, avrA, and hilA) and quorum-sensing (luxS) genes. Our findings imply that plant-derived quercetin could be used as an antibiofilm agent in the food industry to prevent S. Typhimurium biofilm formation.

The Inhibitory Effect of Quercetin on Biofilm Formation of Listeria monocytogenes Mixed Culture and Repression of Virulence

“…Bacteria live in microbial biofilms, which shield them from physical harm, desiccation, and antibiotic agents [ 20 ]. According to numerous studies, foodborne pathogens persist as biofilms on food-contact surfaces (e.g., plastic, steel, glass, and rubber) and impact the quantity, quality, and safety of food products [ 1 , 6 , 21 , 22 ]. Additionally, they destroy surfaces and equipment, contaminate food on a constant basis, pose a significant risk to public health, and their control is a significant barrier in the food production chain [ 23 ].…”

“…Due to its anti-inflammatory, anticancer, and neuroprotective properties, it has a wide range of applications [ 40 , 41 , 42 ]. Owing to its three-ring structure with five hydroxyl groups, it possesses especially strong antioxidant capabilities [ 22 , 35 , 40 , 43 ]. Antioxidants can reduce oxidative stress and prevent biofilm formation by eliminating reactive oxygen species (ROS) accumulated in bacterial cells [ 22 , 35 , 43 ].…”

“…Owing to its three-ring structure with five hydroxyl groups, it possesses especially strong antioxidant capabilities [ 22 , 35 , 40 , 43 ]. Antioxidants can reduce oxidative stress and prevent biofilm formation by eliminating reactive oxygen species (ROS) accumulated in bacterial cells [ 22 , 35 , 43 ]. As a result, antioxidants are potent antibiofilm agents [ 40 , 44 ].…”

Ethanol at Subinhibitory Concentrations Enhances Biofilm Formation in Salmonella Enteritidis

“…The luxS gene participates in the synthesis of autoinducer-2, which acts as a universal quorum-sensing molecule in bacterial pathogens [ 24 , 40 ]. The LuxS quorum-sensing system offers a means for cell-to-cell communications, which is critical for bacterial biofilm production [ 41 , 42 ].…”

“…Cell motility test was conducted based on the method detailed by Roy et al [ 24 ]. The medium was prepared by adding 0.3% and 0.6% agar to TSB-YE for the swimming and swarming assays, respectively, followed by autoclaving.…”