scholarly journals Degradation of N-Acylhomoserine Lactone Quorum Sensing Signaling Molecules by Potato Root Surface-Associated Chryseobacterium Strains

2011 ◽  
Vol 26 (2) ◽  
pp. 144-148 ◽  
Author(s):  
Rumana Rashid ◽  
Tomohiro Morohoshi ◽  
Nobutaka Someya ◽  
Tsukasa Ikeda
Keyword(s):  
Quorum Sensing ◽  
Root Surface ◽  
Signaling Molecules ◽  
Potato Root ◽  
Acylhomoserine Lactone

scholarly journals Inhibition of Quorum Sensing in Serratia marcescens AS-1 by Synthetic Analogs of N-Acylhomoserine Lactone

2007 ◽  
Vol 73 (20) ◽  
pp. 6339-6344 ◽  
Author(s):  
Tomohiro Morohoshi ◽  
Toshitaka Shiono ◽  
Kiyomi Takidouchi ◽  
Masashi Kato ◽  
Norihiro Kato ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Serratia Marcescens ◽  
Biofilm Formation ◽  
Acyl Chain ◽  
Regulatory System ◽  
Homoserine Lactone ◽  
Signal Molecule ◽  
Swarming Motility ◽  
Gram Negative ◽  
Acylhomoserine Lactone

ABSTRACT Quorum sensing is a regulatory system for controlling gene expression in response to increasing cell density. N-Acylhomoserine lactone (AHL) is produced by gram-negative bacteria, which use it as a quorum-sensing signal molecule. Serratia marcescens is a gram-negative opportunistic pathogen which is responsible for an increasing number of serious nosocomial infections. S. marcescens AS-1 produces N-hexanoyl homoserine lactone (C6-HSL) and N-(3-oxohexanoyl) homoserine lactone and regulates prodigiosin production, swarming motility, and biofilm formation by AHL-mediated quorum sensing. We synthesized a series of N-acyl cyclopentylamides with acyl chain lengths ranging from 4 to 12 and estimated their inhibitory effects on prodigiosin production in AS-1. One of these molecules, N-nonanoyl-cyclopentylamide (C9-CPA), had a strong inhibitory effect on prodigiosin production. C9-CPA also inhibited the swarming motility and biofilm formation of AS-1. A competition assay revealed that C9-CPA was able to inhibit quorum sensing at four times the concentration of exogenous C6-HSL and was more effective than the previously reported halogenated furanone. Our results demonstrated that C9-CPA was an effective quorum-sensing inhibitor for S. marcescens AS-1.

scholarly journals An Unprecedented Medium-Chain Diunsaturated N-acylhomoserine Lactone from Marine Roseobacter Group Bacteria

Marine Drugs ◽  
2018 ◽  
Vol 17 (1) ◽  
pp. 20 ◽  
Author(s):  
Lisa Ziesche ◽  
Laura Wolter ◽  
Hui Wang ◽  
Thorsten Brinkhoff ◽  
Marion Pohlner ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Acyl Chain ◽  
Homoserine Lactone ◽  
Compound Identification ◽  
Structural Element ◽  
Mass Spectral ◽  
Acylhomoserine Lactone ◽  
The North ◽  
Bacterial Signaling ◽  
Roseobacter Group

N-acylhomoserine lactones (AHLs), bacterial signaling compounds involved in quorum-sensing, are a structurally diverse group of compounds. We describe here the identification, synthesis, occurrence and biological activity of a new AHL, N-((2E,5Z)-2,5-dodecadienoyl)homoserine lactone (11) and its isomer N-((3E,5Z)-3,5-dodecadienoyl)homoserine lactone (13), occurring in several Roseobacter group bacteria (Rhodobacteraceae). The analysis of 26 strains revealed the presence of 11 and 13 in six of them originating from the surface of the macroalgae Fucus spiralis or sediments from the North Sea. In addition, 18 other AHLs were detected in 12 strains. Compound identification was performed by GC/MS. Mass spectral analysis revealed a diunsaturated C12 homoserine lactone as structural element of the new AHL. Synthesis of three likely candidate compounds, 11, 13 and N-((2E,4E)-2,4-dodecadienoyl)homoserine lactone (5), revealed the former to be the natural AHLs. Bioactivity test with quorum-sensing reporter strains showed high activity of all three compounds. Therefore, the configuration and stereochemistry of the double bonds in the acyl chain seemed to be unimportant for the activity, although the chains have largely different shapes, solely the chain length determining activity. In combination with previous results with other Roseobacter group bacteria, we could show that there is wide variance between AHL composition within the strains. Furthermore, no association of certain AHLs with different habitats like macroalgal surfaces or sediment could be detected.

Close-up on a bacterial informational war in the geocaulosphere

2020 ◽  
Vol 66 (7) ◽  
pp. 447-454 ◽  
Author(s):  
Andrea Chane ◽  
Yvann Bourigault ◽  
Mathilde Bouteiller ◽  
Yoan Konto-Ghiorghi ◽  
Annabelle Merieau ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Communication Systems ◽  
Cell Communication ◽  
Soft Rot ◽  
Homoserine Lactone ◽  
Signaling Molecules ◽  
Disease Symptoms ◽  
Reporter Strains ◽  
Bright Green ◽  
Bright Green Fluorescence

The geocaulosphere is home to microbes that establish communication between themselves and others that disrupt them. These cell-to-cell communication systems are based on the synthesis and perception of signaling molecules, of which the best known belong to the N-acyl-homoserine lactone (AHL) family. Among indigenous bacteria, certain Gram-positive actinobacteria can sense AHLs produced by soft-rot Gram-negative phytopathogens and can degrade the quorum-sensing AHL signals to impair the expression of virulence factors. We mimicked this interaction by introducing dual-color reporter strains suitable for monitoring both the location of the cells and their quorum-sensing and -quenching activities, in potato tubers. The exchange of AHL signals within the pathogen’s cell quorum was clearly detected by the presence of bright green fluorescence instead of blue in a portion of Pectobacterium-tagged cells. This phenomenon in Rhodococcus cells was accompanied by a change from red fluorescence to orange, showing that the disappearance of signaling molecules is due to rhodococcal AHL degradation rather than the inhibition of AHL production. Rhodococci are victorious in this fight for the control of AHL-based communication, as their jamming activity is powerful enough to prevent the onset of disease symptoms.

scholarly journals Interference with Pseudomonas aeruginosa Quorum Sensing and Virulence by the Mycobacterial Pseudomonas Quinolone Signal Dioxygenase AqdC in Combination with the N-Acylhomoserine Lactone Lactonase QsdA

2019 ◽  
Vol 87 (10) ◽  
Author(s):  
Franziska S. Birmes ◽  
Ruth Säring ◽  
Miriam C. Hauke ◽  
Niklas H. Ritzmann ◽  
Steffen L. Drees ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Rhodococcus Erythropolis ◽  
Quorum Quenching ◽  
Signal Molecules ◽  
Content Type ◽  
Acylhomoserine Lactone ◽  
Regulatory Effects ◽  
Epithelial Lung Cells

ABSTRACT The nosocomial pathogen Pseudomonas aeruginosa regulates its virulence via a complex quorum sensing network, which, besides N-acylhomoserine lactones, includes the alkylquinolone signal molecules 2-heptyl-3-hydroxy-4(1H)-quinolone (Pseudomonas quinolone signal [PQS]) and 2-heptyl-4(1H)-quinolone (HHQ). Mycobacteroides abscessus subsp. abscessus, an emerging pathogen, is capable of degrading the PQS and also HHQ. Here, we show that although M. abscessus subsp. abscessus reduced PQS levels in coculture with P. aeruginosa PAO1, this did not suffice for quenching the production of the virulence factors pyocyanin, pyoverdine, and rhamnolipids. However, the levels of these virulence factors were reduced in cocultures of P. aeruginosa PAO1 with recombinant M. abscessus subsp. massiliense overexpressing the PQS dioxygenase gene aqdC of M. abscessus subsp. abscessus, corroborating the potential of AqdC as a quorum quenching enzyme. When added extracellularly to P. aeruginosa cultures, AqdC quenched alkylquinolone and pyocyanin production but induced an increase in elastase levels. When supplementing P. aeruginosa cultures with QsdA, an enzyme from Rhodococcus erythropolis which inactivates N-acylhomoserine lactone signals, rhamnolipid and elastase levels were quenched, but HHQ and pyocyanin synthesis was promoted. Thus, single quorum quenching enzymes, targeting individual circuits within a complex quorum sensing network, may also elicit undesirable regulatory effects. Supernatants of P. aeruginosa cultures grown in the presence of AqdC, QsdA, or both enzymes were less cytotoxic to human epithelial lung cells than supernatants of untreated cultures. Furthermore, the combination of both aqdC and qsdA in P. aeruginosa resulted in a decline of Caenorhabditis elegans mortality under P. aeruginosa exposure.

Isolation of MarineParacoccussp. Ss63 from the SpongeSarcotragussp. and Characterization of its Quorum-Sensing Chemical-Signaling Molecules by LC-MS/MS Analysis

2016 ◽  
Vol 56 (5) ◽  
pp. 330-340 ◽  
Author(s):  
Kumar Saurav ◽  
Ilia Burgsdorf ◽  
Roberta Teta ◽  
Germana Esposito ◽  
Rinat Bar-Shalom ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Signaling Molecules ◽  
Chemical Signaling ◽  
Ms Analysis

scholarly journals Regulation of Quorum Sensing by RpoS inPseudomonas aeruginosa

2000 ◽  
Vol 182 (15) ◽  
pp. 4356-4360 ◽  
Author(s):  
Marvin Whiteley ◽  
Matthew R. Parsek ◽  
E. P. Greenberg
Keyword(s):  
Gene Expression ◽  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Gene Transcription ◽  
Opportunistic Pathogen ◽  
Null Mutant ◽  
Global Regulators ◽  
Acylhomoserine Lactone ◽  
Sensing Systems

ABSTRACT The LasR-LasI and RhlR-RhlI quorum-sensing systems are global regulators of gene expression in the opportunistic pathogenPseudomonas aeruginosa. Previous studies suggest that the RhlR-RhlI system activates expression of rpoS. We constructed merodiploid strains of P. aeruginosa containing the native rpoS gene and an rpoS-lacZ fusion. Studies of lacZ transcription in these strains indicated that rpoS was not regulated by RhlR-RhlI. We also generated an rpoS null mutant. This rpoS mutant showed elevated levels of rhlI (but not rhlR) transcription, elevated levels of the RhlI-generated acylhomoserine lactone quorum-sensing signal, and elevated levels of RhlR-RhlI-regulated gene transcription. These findings indicate that there is a relationship between RpoS and quorum sensing, but rather than the RhlR-RhlI system influencing the expression ofrpoS, it appears that RpoS regulates rhlI.

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