Oregano essential oil-pectin edible films as anti-quorum sensing and food antimicrobial agents

Abstract

Edible films can be used as carriers for antimicrobial compounds to assure food safety and quality; in addition, pathogenesis of food bacteria is related to a cell to cell communication mechanism called quorum sensing (QS). Oregano essential oil (OEO) has proved to be useful as food antimicrobial; however, its food applications can be compromised by the volatile character of its active constituents. Therefore, formulation of edible films containing OEO can be an alternative to improve its food usages. QS inhibitory activity of OEO and pectin-OEO films was evaluated using Chromobacterium violaceum as bacterial model. Additionally, antibacterial activity was tested against Escherichia coli O157:H7, Salmonella Choleraesuis, Staphylococcus aureus, and Listeria monocytogenes. OEO was effective to inhibit bacterial growth at MIC of 0.24 mg/mL for all tested bacteria and MBC of 0.24, 0.24, 0.48, and 0.24 mg/mL against E. coli O157:H7, S. Choleraesuis, S. aureus, and L. monocytogenes, respectively. Pectin-films incorporated with 36.1 and 25.9 mg/mL of OEO showed inhibition diameters of 16.3 and 15.2 mm for E. coli O157:H7; 18.1 and 24.2 mm for S. Choleraesuis; 20.8 and 20.3 mm for S. aureus; 21.3 and 19.3 mm for L. monocytogenes, respectively. Pectin-OEO film (15.7 mg/mL) was effective against E. coli O157:H7 (9.3 mm), S. aureus (9.7 mm), and L. monocytogenes (9.2 mm), but not for S. Choleraesuis. All concentrations of OEO (0.0156, 0.0312, 0.0625 and 0.125 mg/mL) and pectin-OEO films (15.7, 25.9 and 36.1 mg/mL) showed a significant anti-QS activity expressed as inhibition of violacein production by C. violaceum. Additionally, the application of pectin-OEO films was effective reducing total coliforms, yeast, and molds of shrimp and cucumber slices stored at 4°C during 15 d. These results demonstrated the potential of pectin films enriched with OEO as food related microorganisms and QS inhibitors.

Effect of Capsicum Frutescens Extract, Capsaicin, and Luteolin on Quorum Sensing Regulated Phenotypes

“…These results show that PMME affect the QS system in C. violaceum ATCC 12472 and C. violaceum CV026, since these strains have reduced violacein production. Similar results for violacein inhibition have been observed with fruit extracts (Oliveira, Rodrigues, Bertoldi, Taylor, & Pinto, ; Rodrigues, Oliveira et al., ; Rodrigues, Zola et al., ; Truchado et al., ; Vattem et al., ), medicinal plants (Rekha, Vasavi, Vipin, Saptami, & Arun, ; Vandeputte et al., ), and spices (Alvarez et al., ; Choo, Rukayadi, & Hwang, ).…”

“…Plants are sources of secondary metabolites with potential to interfere in bacterial cell–cell communication (Quecán, Rivera, & Pinto, ). Many studies have evaluated the potential of plant‐rich phenolic extracts to inhibit QS (Alvarez et al., ; Corral‐Lugo, Daddaoua, Ortega, Espinosa‐Urgel, & Krell, ; Jakobsen et al., ; Rasmussen et al., ; Truchado et al., ; Vattem, Mihalik, Crixell, & McLean, ; 2016a; Rodrigues, Oliveira et al., ; Rodrigues, Zola et al., ). Despite the numerous works investigating QS interference, no detailed study on the effect of Capsicum peppers and their major compounds on QS has been reported.…”

Anti-quorum sensing activity of phenolic extract from Eugenia brasiliensis (Brazilian cherry)

“…In the plate diffusion assay, the inhibition in this bacterium can be seen as a lack of purple pigmentation around the well, with no detectable alteration on the bacterial growth, as previously observed (Adonizio et al, 2008;Alvarez et al, 2014). However, this assay can only be considered as a preliminary result, since growth inhibition effects exemplified by the colorless transparent halo formed with kanamycin ( Figure 1b) are difficult to be discerned from quorum sensing inhibition which form a turbid colorless halo (Figure 1c and 1c).…”

Resveratrol inclusion complexes: Antibacterial and anti-biofilm activity against Campylobacter spp. and Arcobacter butzleri

“…Keeping this into consideration, the inhibition of cell-to-cell communication underlying the QS could be considered a viable strategy to ensure food safety and quality (Alvarez et al, 2014;Zhang et al, 2014).…”