scholarly journals Inhibition of AI-2 Quorum Sensing and Biofilm Formation in Campylobacter jejuni by Decanoic and Lauric Acids

2022 ◽  
Vol 12 ◽  
Author(s):  
Shenmiao Li ◽  
Kelvin Ka-wan Chan ◽  
Marti Z. Hua ◽  
Greta Gölz ◽  
Xiaonan Lu
Keyword(s):  
Fatty Acids ◽  
Quorum Sensing ◽  
Campylobacter Jejuni ◽  
Lauric Acid ◽  
Biofilm Formation ◽  
Control Strategies ◽  
Decanoic Acid ◽  
Poultry Production ◽  
Bacterial Inactivation ◽  
Autoinducer 2

Campylobacter jejuni is a major bacterial cause of human diarrheal diseases worldwide. Despite its sensitivity to environmental stresses, C. jejuni ubiquitously distributes throughout poultry production chains. Biofilm formation mediated by quorum sensing is suggested to be critical to the survival of C. jejuni in agroecosystem. C. jejuni possesses LuxS, the enzyme involved in the production of autoinducer-2 (AI-2) signaling molecules. In this study, two fatty acids, namely decanoic acid and lauric acid, were identified to be effective in inhibiting AI-2 activity of C. jejuni. Both decanoic acid and lauric acid at 100 ppm inhibited ∼90% AI-2 activity (P < 0.05) of C. jejuni without bacterial inactivation. The biofilm biomass of two C. jejuni strains was reduced by 10–50% (P < 0.05) after treatment by both fatty acids, while increased biofilm formation was observed for one C. jejuni strain. In addition, both fatty acids effectively reduced the motility of all tested C. jejuni strains. These findings can aid in developing alternative C. jejuni control strategies in agri-food and clinical settings.

scholarly journals Autoinducer-2 Triggers the Oxidative Stress Response in Mycobacterium avium, Leading to Biofilm Formation

2008 ◽  
Vol 74 (6) ◽  
pp. 1798-1804 ◽  
Author(s):  
Henriette Geier ◽  
Serge Mostowy ◽  
Gerard A. Cangelosi ◽  
Marcel A. Behr ◽  
Timothy E. Ford
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Quorum Sensing ◽  
Mycobacterium Avium ◽  
Biofilm Formation ◽  
Transcriptional Response ◽  
Opportunistic Pathogen ◽  
Environmental Stresses ◽  
Oxidative Stress Response ◽  
Autoinducer 2

ABSTRACT Mycobacterium avium is an environmental organism and opportunistic pathogen with inherent resistance to drugs, environmental stresses, and the host immune response. To adapt to these disparate conditions, M. avium must control its transcriptional response to environmental cues. M. avium forms biofilms in various environmental settings, including drinking water pipes and potable water reservoirs. In this study, we investigated the role of the universal signaling molecule autoinducer-2 (AI-2) in biofilm formation by M. avium. The addition of the compound to planktonic M. avium cultures resulted in increased biofilm formation. Microarray and reverse transcriptase PCR studies revealed an upregulation of the oxidative stress response upon addition of AI-2. This suggests that the response to AI-2 might be related to oxidative stress, rather than quorum sensing. Consistent with this model, addition of hydrogen peroxide, a known stimulus of the oxidative stress response, to M. avium cultures resulted in elevated biofilm formation. These results suggest that AI-2 does not act as a quorum-sensing signal in M. avium. Instead, biofilm formation is triggered by environmental stresses of biotic and abiotic origins and AI-2 may exert effects on that level.

Quorum sensing signal autoinducer-2 promotes root colonization of Bacillus velezensis SQR9 by affecting biofilm formation and motility

2020 ◽  
Vol 104 (16) ◽  
pp. 7177-7185
Author(s):  
Qin Xiong ◽  
Di Liu ◽  
Huihui Zhang ◽  
Xiaoyan Dong ◽  
Guishan Zhang ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Root Colonization ◽  
Bacillus Velezensis ◽  
Autoinducer 2

Identification of Poultry Meat-Derived Fatty Acids Functioning as Quorum Sensing Signal Inhibitors to Autoinducer-2 (AI-2)

2007 ◽  
Vol 72 (9) ◽  
pp. M363-M368 ◽  
Author(s):  
K.W. Widmer ◽  
K. A. Soni ◽  
M.E. Hume ◽  
R.C. Beier ◽  
P. Jesudhasan ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Quorum Sensing ◽  
Poultry Meat ◽  
Autoinducer 2

scholarly journals Assessment of Antibiofilm Potencies of Nervonic and Oleic Acid against Acinetobacter baumannii Using In Vitro and Computational Approaches

Biomedicines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1133
Author(s):  
Sagar Kiran Khadke ◽  
Jin-Hyung Lee ◽  
Yong-Guy Kim ◽  
Vinit Raj ◽  
Jintae Lee
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Quorum Sensing ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Unsaturated Fatty Acids ◽  
Homoserine Lactone ◽  
Antimicrobial Treatment ◽  
Dynamic Simulations

Acinetobacter baumannii is a nosocomial pathogen, and its biofilms are tolerant to desiccation, nutrient starvation, and antimicrobial treatment on biotic and abiotic surfaces, tissues, and medical devices. Biofilm formation by A. baumannii is triggered by a quorum sensing cascade, and we hypothesized that fatty acids might inhibit its biofilm formation by interfering with quorum sensing. Initially, we investigated the antibiofilm activities of 24 fatty acids against A. baumannii ATCC 17978 and two clinical isolates. Among these fatty acids, two unsaturated fatty acids, nervonic and oleic acid, at 20 μg/mL significantly inhibited A. baumannii biofilm formation without affecting its planktonic cell growth (MICs were >500 μg/mL) and markedly decreased the motility of A. baumannii but had no toxic effect on the nematode Caenorhabditis elegans. Interestingly, molecular dynamic simulations showed that both fatty acids bind to the quorum sensing acyl homoserine lactone synthase (AbaI), and decent conformational stabilities of interactions between the fatty acids and AbaI were exhibited. Our results demonstrate that nervonic and oleic acid inhibit biofilm formation by A. baumannii strains and may be used as lead molecules for the control of persistent A. baumannii infections.

scholarly journals Modulation of Campylobacter jejuni Motility, Adhesion to Polystyrene Surfaces, and Invasion of INT407 Cells by Quorum-Sensing Inhibition

2020 ◽  
Vol 8 (1) ◽  
pp. 104 ◽  
Author(s):  
Katarina Šimunović ◽  
Dina Ramić ◽  
Changyun Xu ◽  
Sonja Smole Možina
Keyword(s):  
Quorum Sensing ◽  
Campylobacter Jejuni ◽  
Biofilm Formation ◽  
Vibrio Harveyi ◽  
Foodborne Pathogen ◽  
Wild Type ◽  
Natural Extracts ◽  
Ethanolic Extracts ◽  
Pure Compounds ◽  
Moderate Positive Correlation

Campylobacter jejuni is a major foodborne pathogen, and the LuxS-mediated quorum-sensing (QS) system influences its motility, biofilm formation, invasion, host colonization, and virulence. QS therefore represents a target for the control of C. jejuni. The aim of this study was to investigate the correlation of QS inhibition with changes in C. jejuni motility, adhesion to polystyrene surfaces, and adhesion to and invasion of INT407 cells. This was achieved by studying (i) the luxS-deficient mutant and (ii) treatment of C. jejuni with 20 natural extracts as six essential oils, 11 ethanolic extracts, and three pure compounds. Compared to the wild-type, the ΔluxS mutant showed decreased motility, adhesion to polystyrene surfaces, and invasion of INT407 cells. The anti-QS effects of the treatments (n = 15/20) were assayed using Vibrio harveyi BB170 bioluminescence. Moderate positive correlation was shown between C. jejuni QS reduction and reduced motility (τ = 0.492, p = 0.024), adhesion to polystyrene surfaces (τ = 0.419, p = 0.008), and invasion (r = 0.394, p = 0.068). The best overall effect was achieved with a Sedum rosea (roseroot) extract, with 96% QS reduction, a 1.41 log (96%) decrease in adhesion to polystyrene surfaces, and an 82% decrease in invasion. We show that natural extracts can reduce motility, adhesion to polystyrene surfaces, and invasion of INT407 cells by C. jejuni through modulation of the LuxS (QS) system.

Identification of Ground Beef–Derived Fatty Acid Inhibitors of Autoinducer-2–Based Cell Signaling

2008 ◽  
Vol 71 (1) ◽  
pp. 134-138 ◽  
Author(s):  
KAMLESH A. SONI ◽  
PALMY JESUDHASAN ◽  
MARTHA CEPEDA ◽  
KENNETH WIDMER ◽  
G. K. JAYAPRAKASHA ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Cell Signaling ◽  
Biofilm Formation ◽  
Ground Beef ◽  
Acid Mixture ◽  
Autoinducer 2 ◽  
Beef Extract ◽  
Reporter Strains ◽  
K 12

Autoinducer-2 (AI-2) molecules are used by several microorganisms to modulate various processes, including bioluminescence, biofilm formation, and virulence expression. Certain food matrices, including ground beef extracts, possess compounds capable of inhibiting AI-2 activity. In the present study, we identified and characterized these AI-2 inhibitors from ground beef extract using hexane solvent extraction and gas chromatography. Gas chromatographic analysis revealed the presence of several fatty acids such as palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1ω9), and linoleic acid (C18:2ω6) that were capable of inhibiting AI-2 activity. These fatty acids were tested (using Vibrio harveyi BB170 and MM32 reporter strains) at different concentrations (1, 5, and 10 mM) to identify differences in the level of AI-2 activity inhibition. AI-2 inhibition ranged from 25 to 90%. A mixture of these fatty acids (prepared at concentrations equivalent to those present in the ground beef extract) produced 52 to 65% inhibition of AI-2 activity. The fatty acid mixture also negatively influenced Escherichia coli K-12 biofilm formation. These results demonstrate that both medium- and long-chain fatty acids in ground beef have the ability to interfere with AI-2–based cell signaling.

scholarly journals Modulation of Swarming and Virulence by Fatty Acids through the RsbA Protein in Proteus mirabilis

2004 ◽  
Vol 72 (12) ◽  
pp. 6836-6845 ◽  
Author(s):  
Shwu-Jen Liaw ◽  
Hsin-Chih Lai ◽  
Won-Bo Wang
Keyword(s):  
Fatty Acids ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Proteus Mirabilis ◽  
Lauric Acid ◽  
Myristic Acid ◽  
Biofilm Formation ◽  
Saturated Fatty Acids ◽  
Extracellular Polysaccharide ◽  
Dependent Pathway

ABSTRACT After sensing external signals, Proteus mirabilis undergoes a multicellular behavior called swarming which is coordinately regulated with the expression of virulence factors. Here we report that exogenously added fatty acids could act as signals to regulate swarming in P. mirabilis. Specifically, while oleic acid enhanced swarming, some saturated fatty acids, such as lauric acid, myristic acid, palmitic acid, and stearic acid, inhibited swarming. We also found that expression of hemolysin, which has been shown to be coordinately regulated with swarming, was also inhibited by the above saturated fatty acids. Previously we identified a gene, rsbA, which may encode a histidine-containing phosphotransmitter of the bacterial two-component signaling system and act as a repressor of swarming and virulence factor expression in P. mirabilis. We found that while myristic acid, lauric acid, and palmitic acid exerted their inhibitory effect on swarming and hemolysin expression through an RsbA-dependent pathway, the inhibition by stearic acid was mediated through an RsbA-independent pathway. Biofilm formation and extracellular polysaccharide (EPS) production play an important role in P. mirabilis infection. We found that RsbA may act as a positive regulator of biofilm formation and EPS production. Myristic acid was found to slightly stimulate biofilm formation and EPS production, and this stimulation was mediated through an RsbA-dependent pathway. Together, these data suggest that fatty acids may act as environmental cues to regulate swarming and virulence in P. mirabilis and that RsbA may play an important role in this process.

Effect of interspecies quorum sensing on the formation of aerobic granular sludge

2011 ◽  
Vol 64 (6) ◽  
pp. 1284-1290 ◽  
Author(s):  
Sheng-Hua Zhang ◽  
Xin Yu ◽  
Feng Guo ◽  
Zhuo-ying Wu
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Essential Element ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Signal Molecules ◽  
Small Signal ◽  
Autoinducer 2

Quorum sensing (QS) is a form of microbial communication that relies on small signal molecules to regulate group behaviors such as biofilm formation in response to population density. In this study, we attempted to apply the paradigm of bacterial QS to aerobic granular sludge (AGS) formation for wastewater treatment. An essential element of interspecies QS signals, boron, was added to a sequencing batch reactor (SBR) to stimulate AGS growth. Bioassays elaborated the activity of autoinducer-2 (AI-2). We found that boron accelerated AGS growth, resulting in improved settlement performance and increased biomass in the SBR. During continuous SBR operation, the AGS showed an obvious increase in AI-2 activity, which implies that interspecies QS was closely associated with AGS formation. Analysis of EPS showed that boron stimulated tryptophan production, and increased the hydrophobia of AGS. From these results, it was speculated that the addition of boron may have promoted the formation of boron complexed to (R)-4, 5-dihydroxy-2,3-pentanedione (DPD) as the precursor of AI-2, which resulted in accelerated interspecies QS. The results also suggested QS as a novel regulation target for the biogranulation process, such as AGS formation.

scholarly journals Role of the luxS Quorum-Sensing System in Biofilm Formation and Virulence of Staphylococcus epidermidis

2006 ◽  
Vol 74 (1) ◽  
pp. 488-496 ◽  
Author(s):  
Lin Xu ◽  
Hualin Li ◽  
Cuong Vuong ◽  
Viveka Vadyvaloo ◽  
Jianping Wang ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Mutant Strain ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Bacterial Pathogens ◽  
Sensing System ◽  
Autoinducer 2 ◽  
Enhanced Production ◽  
Quorum Sensing System ◽  
Biofilm Development

ABSTRACT Nosocomial infections caused by Staphylococcus epidermidis are characterized by biofilm formation on implanted medical devices. Quorum-sensing regulation plays a major role in the biofilm development of many bacterial pathogens. Here, we describe luxS, a quorum-sensing system in staphylococci that has a significant impact on biofilm development and virulence. We constructed an isogenic ΔluxS mutant strain of a biofilm-forming clinical isolate of S. epidermidis and demonstrated that luxS signaling is functional in S. epidermidis. The mutant strain showed increased biofilm formation in vitro and enhanced virulence in a rat model of biofilm-associated infection. Genetic complementation and addition of autoinducer 2-containing culture filtrate restored the wild-type phenotype, demonstrating that luxS repressed biofilm formation through a cell-cell signaling mechanism based on autoinducer 2 secretion. Enhanced production of the biofilm exopolysaccharide polysaccharide intercellular adhesin in the mutant strain is presumably the major cause of the observed phenotype. The agr quorum-sensing system has previously been shown to impact biofilm development and biofilm-associated infection in a way similar to that of luxS, although by regulation of different factors. Our study indicates a general scheme of quorum-sensing regulation of biofilm development in staphylococci, which contrasts with that observed in many other bacterial pathogens.

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