Essential oil components inhibit biofilm formation in Erwinia carotovora and Pseudomonas fluorescens via anti-quorum sensing activity

Gan

Comp Rev Food Sci Food Safe

et al. 2020

In recent decades, reduced antimicrobial effectiveness, increased bacterial infection, and newly emerged microbial resistance have become global public issues, leading to an urgent need to find effective strategies to counteract these problems. Strategies targeting bacterial virulence factors rather than bacterial survival have attracted increasing interest, since the modulation of virulence factors may prevent the development of drug resistance in bacteria. Spices are promising natural sources of antivirulence compounds owing to their wide availability, diverse antivirulence phytochemical constituents, and generally favorable safety profiles. Essential oils are the predominant and most important antivirulence components of spices. This review addresses the recent efforts of using spice essential oils to inhibit main bacterial virulence traits, including the quorum sensing system, biofilm formation, motility, and toxin production, with an intensive discussion of related mechanisms. We hope that this review can provide a better understanding of the antivirulence properties of spice essential oils, which have the potential to be used as antibiotic alternatives by targeting bacterial virulence. K E Y W O R D Sbiofilm, mechanisms, motility, quorum sensing, spice essential oils, toxin 1018

Section: Bacterial Biofilmmentioning

confidence: 99%

Antivirulence properties and related mechanisms of spice essential oils: A comprehensive review

Gan

Comp Rev Food Sci Food Safe

et al. 2020

“…Inhibition of violacein production of C. violaceum is commonly used as an indicator of QS inhibition in gram-negative bacteria ( 31 , 32 ). The QS mechanism in C. violaceum ATCC 12472 is controlled by the CviI/CviR system (Luxl/LuxR homologs), correlated with the production of the purple pigment violacein in response to threshold concentrations of the autoinducer N-hexanoyl homoserine lactone ( 61 ).…”

Section: Resultsmentioning

confidence: 99%

“…Food deterioration, at least in part, is regulated by a mechanism of cell-to-cell communication (such as QS). Until now, only a few studies have developed food preservation techniques based on the anti-QS property of EOs ( 32 ). The search for an efficient QS inhibitor that can inhibit the spoilage of food products is a promising alternative ( 33 ).…”

Section: Introductionmentioning

confidence: 99%

Rheological Behavior, Antimicrobial and Quorum Sensig Inhibition Study of an Argentinean Oregano Essential Oil Nanoemulsion

et al. 2020

In this study, Argentinean oregano essential oil (OEO) nanoemulsions (NEs) were developed. Four NEs were prepared: a control (CNE), EONE1 (10.6 mg EO/g NE), EONE2 (106 mg EO/ g NE), and EONE3 (160 mg EO/g NE) and tested for antimicrobial activity against Staphylococcus aureus ATCC 13565, Listeria monocytogenes Scott A, Pseudomonas aeruginosa ATCC 14213, and Escherichia coli O157:H7 using a broth microdilution assay and quorum sensing inhibition in a model using Chromobacterium violaceum ATCC 12472, where the production of violacein was quantified. The chemical composition of the EO was determined by gas chromatography–mass spectrometry. The average particle size (nm) and polydispersity index were monitored over 14 days at two different storage temperatures (4 and 23°C). A rheological behavior study was carried out using a dynamic shear rheometer, and flow curves, as well as viscoelastic properties, were determined. E. coli and L. monocytogenes were the most sensitive microorganisms to EONE (MIC of 2 and 5 mg/ml for EOEN3). Sub-MICs for NE were found at lower concentrations than those for pure EO. A significant reduction in violet pigment intensity and colorless coloration ( p < 0.05) were observed at different NE concentrations concerning the control sample. The flow behavior index ( n ) decreased, and the consistency index (k) increased when the EO concentration was increased. CNE, EONE1, and EONE2 showed liquid-like behavior (G′ < G″) in the low-frequency region, whereas a solid-like behavior (G′ > G″) was observed in the high-frequency region, presenting a viscoelastic behavior, appearing as a wormlike micellar solution. For EONE3, a strong increase in both moduli was observed with increasing OEO concentration. The G′ was about one order of magnitude higher than the G″ over the whole frequency range, indicating the presence of a gel-like structure. The incorporation of EOs into an NE increased their stability, lowering the particle size, leading to a wormlike micelle with higher viscosity. Moreover, this NE had good antimicrobial activity and novel quorum-sensing inhibition activity. The results of this study indicated that Argentinean OEO NE could be used in a food system as a natural and stable antimicrobial agent.

Saudi Journal of Biological Sciences

“…EPS is a physical important barrier for bacteria which helps to produce DNA, nucleic acid, extra cellular leakage materials for adhesion, protection and prevention of bacteria from external antibiotics ( Nazzaro et al, 2013 , Rajivgandhi et al, 2014 , Zhang et al, 2018 ). It is an important virulence factor in mode anti-biofilm formation action which gives the structure and shape to bacterial biofilm lead to biofilm matrix ( Lodhia et al, 2009 ).…”

Section: Resultsmentioning

confidence: 99%

Preparative HPLC fraction of Hibiscus rosa-sinensis essential oil against biofilm forming Klebsiella pneumoniae

Yang

Rajivgandhi

Ramachandran

et al. 2020

Recent years Klebsiella pneumoniae ( K. pneumoniae ) biofilm formation (BF) is emerging thread worldwide. For tackling this problem, we have chosen Hibiscus rosa-. pneumoniae. The HPLC purified essential oils (EOs sinensis (H. rosa-sinensis) (HRS) to inhibit the BF K) of H. rosa-sinensis was performed against BF K. pneumoniae and showed concentration dependent biofilm inhibition. At the MBIC of EOs (90 µg/ml), the biofilm inhibition was showed at 92% against selected BF K. Pneumoniae . The biofilm metabolic assay, exopolysaccharide quantification and hydrophobicity index variation results exhibited with 88%, 92% and 89% reduction at 90 μg/mL was observed respectively. In addition, the morphological modification of MBIC treated K. pneumoniae was clearly viewed by scanning electron microscope (SEM). Overall, all the invitro experiments result were confirmed that the MBIC of H. rosa-sinensis EOs was very effective against BF K. pneumonia.