scholarly journals Reduction of exoprotease production in Aeromonas hydrophila by tomato fruits extract (Lycopersicon esculentum Mill.)

2006 ◽  
Vol 4 (2) ◽  
pp. 55-64
Author(s):  
NUR AINI ◽  
SUTARNO SUTARNO ◽  
ARI SUSILOWATI
Keyword(s):  
Quorum Sensing ◽  
Ethyl Acetate ◽  
Aeromonas Hydrophila ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Signal Molecule ◽  
Tomato Fruits ◽  
Sensing System ◽  
Quorum Sensing Inhibitors ◽  
Assay Result

Aeromonas hydrophila is pathogenic bacteria in fish. One of its virulence factors is exoprotease. The production of exoprotease is controlled by a quorum sensing system. Quorum sensing is an intercellular communication of bacteria that using a signal molecule of C4-HSL. The exoprotease production of A. hydrophila can be blocked by using quorum sensing inhibitors. The inhibition of quorum sensing of A. hydrophila can be conducted by C4-HSL analogs molecules. In this research, the molecules that predicted as quorum sensing inhibitors and act as C4-HSL analog molecules were furanone from tomato fruits. The inhibition of quorum sensing of A. hydrophila could be shown by a reduction of exoprotease production. The aim of this research was to determine the reduction of exoprotease production of A. hydrophila by extracts of n-hexane, ethyl acetate and methanol of tomato fruits with the concentrations of 0%, 2%, 4%, 6% and 8%, respectively. The qualitative exoprotease assay result showed that n-hexane extract of tomato had no effect on growth and exoprotease production of A. hydrophila. As much as 4% of ethyl acetate extract of tomato fruits could inhibit exoprotease production, but affect A. hydrophilla growth. Meanwhile, 4% methanol extract of tomato fruits could inhibit exoprotease production, without affect A. hydrophilla growth. The quantitative exoprotease assay result showed that 4% of methanol extract could inhibit exoprotease production by 71.68% without affect the growth of A. hydrophila.

scholarly journals Inhibition of exoprotease production in Aeromonas hydrophila by rhizome extract of temu lawak (Curcuma xanthorrhiza (Roxb.)

2006 ◽  
Vol 4 (2) ◽  
pp. 45-54
Author(s):  
UMI LESTARI ◽  
ARTINI PANGASTUTI ◽  
ARI SUSILOWATI
Keyword(s):  
Quorum Sensing ◽  
Ethyl Acetate ◽  
Aeromonas Hydrophila ◽  
Ethanol Extract ◽  
Homoserine Lactone ◽  
Sensing System ◽  
Development Of Resistance ◽  
Quorum Sensing System ◽  
Assay Result ◽  
Curcuma Xanthorrhiza

Conventional treatment of infectious diseases is based on compounds that kill or inhibit the growth of bacteria. A major concern with this approach is the frequent development of resistance to antimicrobial compounds. The discovery of communication (quorum sensing system) regulating bacterial virulence opens up ways to control certain bacterial infectious without interfering the growth. The fish pathogen Aeromonas hydrophila produces quorum sensing signal, NButanoyl-L-Homoserine Lactone (C4-HSL). C4-HSL regulates exoprotease synthesis, a virulence factor of A. hydrophila. Expression of exoprotease can be blocked by using quorum sensing inhibitor. The purpose of this study was to investigate the inhibiting effect of Curcuma xanthorrhiza (Roxb.) extract to exoprotease production of A. hydrophila. Extraction was conducted by using n-hexane, ethyl acetate and ethanol. The qualitative exoprotease assay result showed that n-hexane extract of C. xanthorrhiza had not effect on growth and exoprotease production of A. hydrophila. Meanwhile, 4% of ethyl acetate and ethanol extract of C. xanthorrhiza can inhibit exoprotease production without affecting A. hydrophilla growth. The quantitative exoprotease assay result showed that 4% of ethyl acetate and ethanol extract can inhibit the exoprotease production by 93,9% and 95,6%. The growth of A. hydrophila was not affected by this extract.

Novel bacteria degrading N-acylhomoserine lactones and their use as quenchers of quorum-sensing-regulated functions of plant-pathogenic bacteria

Microbiology ◽  
2003 ◽  
Vol 149 (8) ◽  
pp. 1981-1989 ◽  
Author(s):  
Stéphane Uroz ◽  
Cathy D'Angelo-Picard ◽  
Aurélien Carlier ◽  
Miena Elasri ◽  
Carine Sicot ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Pathogenic Bacteria ◽  
Rhodococcus Erythropolis ◽  
Homoserine Lactone ◽  
Signal Molecules ◽  
In Planta ◽  
Signal Molecule ◽  
Violacein Production ◽  
Regulated Functions

Bacteria degrading the quorum-sensing (QS) signal molecule N-hexanoylhomoserine lactone were isolated from a tobacco rhizosphere. Twenty-five isolates degrading this homoserine lactone fell into six groups according to their genomic REP-PCR and rrs PCR-RFLP profiles. Representative strains from each group were identified as members of the genera Pseudomonas, Comamonas, Variovorax and Rhodococcus. All these isolates degraded N-acylhomoserine lactones other than the hexanoic acid derivative, albeit with different specificity and kinetics. One of these isolates, Rhodococcus erythropolis strain W2, was used to quench QS-regulated functions of other microbes. In vitro, W2 strongly interfered with violacein production by Chromobacterium violaceum, and transfer of pathogenicity in Agrobacterium tumefaciens. In planta, R. erythropolis W2 markedly reduced the pathogenicity of Pectobacterium carotovorum subsp. carotovorum in potato tubers. These series of results reveal the diversity of the QS-interfering bacteria in the rhizosphere and demonstrate the validity of targeting QS signal molecules to control pathogens with natural bacterial isolates.

Attenuation of quorum sensing-mediated virulence in Gram-negative pathogenic bacteria: implications for the post-antibiotic era

MedChemComm ◽  
2015 ◽  
Vol 6 (2) ◽  
pp. 259-272 ◽  
Author(s):  
Ravindra Pal Singh
Keyword(s):  
Quorum Sensing ◽  
Pathogenic Bacteria ◽  
Quorum Quenching ◽  
Gram Negative ◽  
Sensing System ◽  
Quorum Sensing System

Quorum quenching compounds blocked quorum sensing system of bacteria by several mechanisms (a, b, c and d).

scholarly journals The Plant Pathogen Pantoea ananatis Produces N-Acylhomoserine Lactone and Causes Center Rot Disease of Onion by Quorum Sensing

2007 ◽  
Vol 189 (22) ◽  
pp. 8333-8338 ◽  
Author(s):  
Tomohiro Morohoshi ◽  
Yuta Nakamura ◽  
Go Yamazaki ◽  
Akio Ishida ◽  
Norihiro Kato ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Receptor Gene ◽  
Homoserine Lactone ◽  
Pantoea Ananatis ◽  
Signal Molecule ◽  
Acylhomoserine Lactone ◽  
Sensing System ◽  
Quorum Sensing System ◽  
Rot Disease

ABSTRACT A number of gram-negative bacteria have a quorum-sensing system and produce N-acyl-l-homoserine lactone (AHL) that they use them as a quorum-sensing signal molecule. Pantoea ananatis is reported as a common colonist of wheat heads at ripening and causes center rot of onion. In this study, we demonstrated that P. ananatis SK-1 produced two AHLs, N-hexanoyl-l-homoserine lactone (C6-HSL) and N-(3-oxohexanoyl)-l-homoserine lactone (3-oxo-C6-HSL). We cloned the AHL-synthase gene (eanI) and AHL-receptor gene (eanR) and revealed that the deduced amino acid sequence of EanI/EanR showed high identity to those of EsaI/EsaR from P. stewartii. EanR repressed the ean box sequence and the addition of AHLs resulted in derepression of ean box. Inactivation of the chromosomal eanI gene in SK-1 caused disruption of exopolysaccharide (EPS) biosynthesis, biofilm formation, and infection of onion leaves, which were recovered by adding exogenous 3-oxo-C6-HSL. These results demonstrated that the quorum-sensing system involved the biosynthesis of EPS, biofilm formation, and infection of onion leaves in P. ananatis SK-1.

Strategies for inhibiting quorum sensing

2017 ◽  
Vol 1 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Paul Williams
Keyword(s):  
Quorum Sensing ◽  
Regulatory Networks ◽  
Pathogenic Bacteria ◽  
Bacterial Cells ◽  
Therapy Outcomes ◽  
Signal Molecule ◽  
Bacterial Populations ◽  
Conventional Antibiotics ◽  
Micro Organisms

The ability of bacterial cells to synchronize their behaviour through quorum sensing (QS) regulatory networks enables bacterial populations to mount co-operative responses against competing micro-organisms and host immune defences and to adapt to environmental challenges. Since QS controls the ability of many pathogenic bacteria to cause disease, it is an attractive target for novel antibacterial agents that control infection through inhibition of virulence and by rendering biofilms more susceptible to conventional antibiotics and host clearance pathways. QS systems provide multiple druggable molecular targets for inhibitors (QSIs) that include the enzymes involved in QS signal molecule biosynthesis and the receptors involved in signal transduction. Considerable advances in our understanding of the chemical biology of QS systems and their inhibition have been made, some promising QS targets structurally characterized, QSI screens devised and inhibitors identified. However, much more work is required before any QSI ‘hits’ with the appropriate pharmacological and pharmacokinetic properties can enter human clinical trials. Indeed, the relative efficacy of QSIs alone or as prophylactics or therapeutics or as adjuvants in combination with conventional antibiotics still needs to be extensively evaluated in vivo. Particular attention must be given to the measurement of successful QSI therapy outcomes with respect to bacterial clearance, immune response and pathophysiology. Currently, our understanding of the potential of QS as a promising antibacterial target suggests that it is likely to be of value with respect to a limited number of major pathogens.

scholarly journals Genome Sequence Analysis Reveals Evidence of Quorum-Sensing Genes Present in Aeromonas hydrophila strain KOR1, Isolated from a Mangrove Plant ( Kandelia obovata )

2015 ◽  
Vol 3 (6) ◽  
Author(s):  
Mengqing Yin ◽  
Zhiping Ma ◽  
Zhonghua Cai ◽  
Guanghui Lin ◽  
Jin Zhou
Keyword(s):  
Sequence Analysis ◽  
Quorum Sensing ◽  
Genome Sequence ◽  
Aeromonas Hydrophila ◽  
Rhizosphere Soil ◽  
Kandelia Obovata ◽  
Mangrove Plant ◽  
Signal Molecule ◽  
Genome Sequence Analysis ◽  
Encoding Gene

Aeromonas hydrophila strain KOR1, isolated from mangrove rhizosphere soil, has the ability to produce the quorum-sensing signal molecule. Here, we report the 4.78-Mb genome sequence of strain KOR1, and found its quorum-sensing encoding gene LuxR . The data will be crucial to understanding the quorum-sensing-dependent phenotypes of this bacterium.

scholarly journals Specificity and genetic polymorphism in the Vfm quorum sensing system of plant pathogenic bacteria of the genus Dickeya

2022 ◽  
Author(s):  
Nicole Hugouvieux‐Cotte‐Pattat ◽  
Monique Royer ◽  
Erwan Gueguen ◽  
Paul Le Guen ◽  
Roderich D. Süssmuth ◽  
...  
Keyword(s):  
Genetic Polymorphism ◽  
Quorum Sensing ◽  
Pathogenic Bacteria ◽  
Plant Pathogenic Bacteria ◽  
Sensing System ◽  
Quorum Sensing System

Quorum sensing of pathogenic bacteria and quorum-sensing inhibitors

2012 ◽  
Vol 57 (21) ◽  
pp. 1964-1977 ◽  
Author(s):  
ZongHui YUAN ◽  
ZhenLi LIU ◽  
MengHong DAI ◽  
HaiHong HAO ◽  
GuYue CHENG
Keyword(s):  
Quorum Sensing ◽  
Pathogenic Bacteria ◽  
Quorum Sensing Inhibitors

scholarly journals Determination of the antimicrobial and antibiofilm effects and ‘Quorum Sensing’ inhibition potentials of Castanea sativa Mill. extracts

2020 ◽  
Vol 48 (1) ◽  
pp. 66-78
Author(s):  
Saliha EKŞİ ◽  
Ülkü Zeynep ÜREYEN ESERTAŞ ◽  
Ali Osman KILIÇ ◽  
Nebahat EJDER ◽  
Barış UZUNOK
Keyword(s):  
Quorum Sensing ◽  
Ethyl Acetate ◽  
Antimicrobial Agents ◽  
Methanol Extract ◽  
Bacterial Species ◽  
Castanea Sativa ◽  
Diffusion Method ◽  
Biofilm Inhibition ◽  
Pao1 Strain

The rapid rise of resistance causes existing antibiotics to become dysfunctional. Therefore, search for new antimicrobial active ingredients has increased in recent years. In this study, flower extracts of Castanea sativa were examined for antimicrobial and anti-quorum sensing aspects. The antimicrobial properties of methanol, ethyl acetate, ethanol and hexane extracts of C. sativa against some gram-positive and gram-negative bacterial species, as well as yeasts (Candida albicans and Candida parapsilosis) were investigated by the agar well diffusion method. The minimum inhibition concentration (MIC) and minimum bactericidal concentrations (MBC) of C. sativa extracts were also determined. Chromobacterium violaceum ATCC 12472, C. violaceum 35352, C. violaceum VIR07 and C. violaceum CV026 indicator strains were used for determination of the quorum sensing inhibitions, and the Pseudomonas aeruginosa PAO1 strain was used for the swarming tests. Additionally, biofilm inhibition was detected by the spectrophotometric method using the P. aeruginosa PAO1 strain. Methanol, ethanol and ethyl acetate extracts of C. sativa was found to have high antibacterial and antifungal effects, while the methanol extract also had anti-quorum sensing, anti- swarming and biofilm inhibition effects, but no activity was found in the n- hexane extract. To the best of our knowledge this is the first report revealed that methanol extract obtained from C. sativa flowers induced anti-quorum sensing activities mainly inhibited the violacein production, swarming and biofilm formation. The present investigation provided evidence that the C. sativa flower extract maybe a potential source of antimicrobial agents. Therefore, much attention should be paid to C. sativa flower content, which could be used with high efficacy against microorganisms.

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