scholarly journals Impact of Moderate Heat, Carvacrol, and Thymol Treatments on the Viability, Injury, and Stress Response ofListeria monocytogenes

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
L. Guevara ◽  
V. Antolinos ◽  
A. Palop ◽  
P. M. Periago
Keyword(s):  
Stress Response ◽  
Essential Oil ◽  
Synergistic Effects ◽  
Inactivation Kinetics ◽  
Adaptive Networks ◽  
Two Dimensional Gel Electrophoresis ◽  
Stressed Cells ◽  
Oflisteria Monocytogenes ◽  
Safe Food ◽  
Essential Oil Compounds

The microbial safety and stability of minimally processed foods are based on the application of combined preservative factors. Since microorganisms are able to develop adaptive networks to survive under conditions of stress, food safety may be affected, and therefore understanding of stress adaptive mechanisms plays a key role in designing safe food processing conditions. In the present study, the viability and the sublethal injury ofListeria monocytogenesexposed to moderate heat (55°C) and/or essential oil compounds (carvacrol and thymol, 0.3 mM) treatments were studied. Synergistic effects were obtained when combining mild heat (55°C) with one or both essential oil compounds, leading to inactivation kinetics values three to four times lower than when using heat alone. All the treatments applied caused some injury in the population. The injury levels ranged from around 20% of the surviving population under the mildest conditions to more than 99.99% under the most stringent conditions. Protein extracts of cells exposed to these treatments were analysed by two-dimensional gel electrophoresis. The results obtained revealed that stressed cells exhibited differential protein expression to control cells. The proteins upregulated under these stressing conditions were implicated, among other functions, in stress response, metabolism, and protein refolding.

scholarly journals Synergistic antibacterial combination of Lavandula latifolia Medik. essential oil with camphor

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nursenem Karaca ◽  
Görkem Şener ◽  
Betül Demirci ◽  
Fatih Demirci
Keyword(s):  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Antibacterial Effect ◽  
Synergistic Effects ◽  
Pharmaceutical Formulations ◽  
Human Pathogens ◽  
Broth Microdilution ◽  
Antibacterial Effects ◽  
Lavandula Latifolia

AbstractCombination of various compounds and essential oils for pharmaceutical formulations withdraw attention. In this present study, it was aimed to evaluate the in vitro potential synergistic antibacterial effect of Lavandula latifolia (spike lavender) essential oil with camphor by using the checkerboard method against the human pathogens; Staphylococcus aureus and Listeria monocytogenes. Pharmacopoeia quality L. latifolia essential oil and racemic camphor were analyzed and verified by GC-FID and GC/MS, simultaneously. In vitro antibacterial activity of essential oil and camphor (MIC range: 0.16–20 mg/mL) and standard antimicrobial clarithromycin (MIC range: 0.125–16 μg/mL) were carried out by broth microdilution against S. aureus and L. monocytogenes standard strains, respectively. Resulting antibacterial effects were evaluated for their fractional inhibitory concentrations (FICs) as antagonistic, additive and synergistic effects. The analytical results showed that the major component of essential oil was linalool (45.2%) and 1,8-cineole (25.6%). Antibacterial effects of essential oil were determined as MIC 1.25–5 mg/mL. As a result of the experiments, L. latifolia essential oil–camphor combinations were identified as “synergistic (FIC ≤ 0.5), and additive (0.5 < FIC ≤ 1)” in the respective combinations, suggesting further evaluation for formulations for potential antimicrobial applications in food and pharmaceuticals.

scholarly journals Anti-biofilm and Virulence Factor-Reducing Activities of Essential Oils and Oil Components as a Possible Option for Bacterial Infection Control

Planta Medica ◽  
2020 ◽  
Vol 86 (08) ◽  
pp. 520-537 ◽  
Author(s):  
Jürgen Reichling
Keyword(s):  
Quorum Sensing ◽  
Essential Oil ◽  
Essential Oils ◽  
Virulence Factor ◽  
Model Organisms ◽  
Regulation System ◽  
Expression Of Genes ◽  
Reporter Strains ◽  
Violacein Production ◽  
Essential Oil Compounds

AbstractPathogenic biofilm-associated bacteria that adhere to biological or nonbiological surfaces are a big challenge to the healthcare and food industries. Antibiotics or disinfectants often fail in an attempt to eliminate biofilms from those surfaces. Based on selected experimental research, this review deals with the potential biofilm-inhibiting, virulence factor-reducing, and biofilm-eradicating activities of essential oils and single essential oil compounds using Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Chromobacterium violaceum as model organisms. In addition, for the bacteria reviewed in this overview, different essential oils and essential oil compounds were reported to be able to modulate the expression of genes that are involved in the formation of autoinducer molecules, biofilms, and virulence factors. The anti-quorum sensing activity of some essential oils and single essential oil compounds was demonstrated using the gram-negative bacterium C. violaceum. Reporter strains of this bacterium produce the violet-colored compound violacein whose synthesis is regulated by quorum sensing autoinducer molecules called acylhomeserinlactones. Of great interest was the discovery that enantiomeric monoterpenes affected the quorum sensing regulation system in different ways. While the (+)-enantiomers of carvone, limonene, and borneol increased violacein formation, their (−)-analogues inhibited violacein production.For the successful eradication of biofilms and the bacteria living inside them, it is absolutely necessary that the lipophilic volatile substances can penetrate into the aqueous channels of biofilms. As shown in recent work, hydrophilic nano-delivery systems encapsulating essential oils/essential oil compounds with antibacterial effects may contribute to overcome this problem.

Effects of Foeniculum vulgare essential oil compounds, fenchone and limonene, on experimental wound healing

2017 ◽  
Vol 92 (4) ◽  
pp. 274-282 ◽  
Author(s):  
I Keskin ◽  
Y Gunal ◽  
S Ayla ◽  
B Kolbasi ◽  
A Sakul ◽  
...  
Keyword(s):  
Wound Healing ◽  
Essential Oil ◽  
Foeniculum Vulgare ◽  
Essential Oil Compounds

Essential oil compounds in a historical sample of marjoram (Origanum majorana L., Lamiaceae)

2002 ◽  
Vol 17 (3) ◽  
pp. 175-180 ◽  
Author(s):  
Johannes Novak ◽  
Jan Langbehn ◽  
Friedrich Pank ◽  
Chlodwig M. Franz
Keyword(s):  
Essential Oil ◽  
Historical Sample ◽  
Origanum Majorana ◽  
Essential Oil Compounds

Chemotaxonomic value of the essential oil compounds in species of Teucrium pumilum aggregate

2000 ◽  
Vol 55 (5) ◽  
pp. 397-401 ◽  
Author(s):  
Isabel Pérez ◽  
Maria Amparo Blázquez ◽  
Herminio Boira
Keyword(s):  
Essential Oil ◽  
Essential Oil Compounds

Thermal and Starvation Stress Response of Escherichia coli O157:H7 Isolates Selected from Agricultural Environments

2016 ◽  
Vol 79 (10) ◽  
pp. 1673-1679 ◽  
Author(s):  
ACHYUT ADHIKARI ◽  
ANDY BARY ◽  
CRAIG COGGER ◽  
CALEB JAMES ◽  
GÜLHAN ÜNLÜ ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Heat Stress ◽  
Stress Response ◽  
Weibull Model ◽  
Stress Conditions ◽  
Inactivation Kinetics ◽  
Escherichia Coli O157 ◽  
Starvation Stress ◽  
E Coli ◽  
Response To Stress

ABSTRACT Pathogens exposed to agricultural production environments are subject to multiple stresses that may alter their survival under subsequent stress conditions. The objective of this study was to examine heat and starvation stress response of Escherichia coli O157:H7 strains isolated from agricultural matrices. Seven E. coli O157:H7 isolates from different agricultural matrices—soil, compost, irrigation water, and sheep manure—were selected, and two ATCC strains were used as controls. The E. coli O157:H7 isolates were exposed to heat stress (56°C in 0.1% peptone water for up to 1 h) and starvation (in phosphate-buffered saline at 37°C for 15 days), and their survival was examined. GInaFiT freeware tool was used to perform regression analyses of the surviving populations. The Weibull model was identified as the most appropriate model for response of the isolates to heat stress, whereas the biphasic survival curves during starvation were fitted using the double Weibull model, indicating the adaptation to starvation or a resistant subpopulation. The inactivation time during heating to achieve the first decimal reduction time (δ) calculated with the Weibull parameters was the highest (45 min) for a compost isolate (Comp60A) and the lowest (28 min) for ATCC strain 43895. Two of the nine isolates (ATCC 43895 and a manure isolate) had β &lt; 1, indicating that surviving populations adapted to heat stress, and six strains demonstrated downward concavity (β &gt; 1), indicating decreasing heat resistance over time. The ATCC strains displayed the longest δ2 (&gt;1,250 h) in response to starvation stress, compared with from 328 to 812 h for the environmental strains. The considerable variation in inactivation kinetics of E. coli O157:H7 highlights the importance of evaluating response to stress conditions among individual strains of a specific pathogen. Environmental isolates did not exhibit more robust response to stress conditions in this study compared with ATCC strains.

Effect of Plant Essential Oils and Their Major Constituents on Cypermethrin Tolerance Associated Detoxification Enzyme Activities in Spodoptera litura (Lepidoptera: Noctuidae)

2019 ◽  
Vol 112 (5) ◽  
pp. 2167-2176 ◽  
Author(s):  
Torranis Ruttanaphan ◽  
Wanchai Pluempanupat ◽  
Chutikan Aungsirisawat ◽  
Polnarong Boonyarit ◽  
Gaelle Le Goff ◽  
...  
Keyword(s):  
Essential Oil ◽  
Synergistic Effect ◽  
Essential Oils ◽  
Spodoptera Litura ◽  
Cytochromes P450 ◽  
Detoxification Enzymes ◽  
Plant Essential Oils ◽  
Activity Measurements ◽  
Lepidoptera Noctuidae ◽  
Essential Oil Compounds

Abstract Essential oils are well known to act as biopesticides. This research evaluated the acute toxicity and synergistic effect of essential oil compounds in combination with cypermethrin against Spodoptera litura Fabricius (Lepidoptera: Noctuidae). The effects of distillation extracts of essential oils from Alpinia galanga Zingiberaceae (Zingiberales) rhizomes and Ocimum basilicum Lamiaceae (Lamiales) leaves; one of their primary essential oil compounds 1,8-cineole; and linalool were studied on second-instar S. litura by topical application under laboratory conditions. The results showed that A. galanga had the highest control efficiency, whereas1,8-cineole provided a moderate efficacy. The mixtures of linalool, 1,8-cineole, O. basilicum, or A. galanga with cypermethrin were synergistic on mortality. Activity measurements of the main detoxification enzymes show that linalool and 1,8-cineole inhibit the activity of cytochromes P450 and carboxylesterases, which could explain their synergistic effect. Based on our results, the use of these mixtures represents an ideal eco-friendly approach, helping to manage cypermethrin resistance of S. litura.

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