Erratum to: Identification of N-Hexadecanoyl-L-homoserine lactone (C16-AHL) as signal molecule in halophilic bacterium Halomonas smyrnensis AAD6

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.

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Recombinant N-acyl homoserine lactone-Lactonase AiiAQSI-1 Attenuates Aeromonas hydrophila Virulence Factors, Biofilm Formation and Reduces Mortality in Crucian Carp

Marine Drugs ◽

10.3390/md17090499 ◽

2019 ◽

Vol 17 (9) ◽

pp. 499 ◽

Cited By ~ 2

Author(s):

Bao Zhang ◽

Xiyi Zhuang ◽

Liyun Guo ◽

Robert J. C. McLean ◽

Weihua Chu

Keyword(s):

Virulence Factors ◽

Aeromonas Hydrophila ◽

Biofilm Formation ◽

Crucian Carp ◽

Homoserine Lactone ◽

In Vivo Studies ◽

Acyl Homoserine Lactone ◽

Signal Molecule ◽

Promising Alternative ◽

Feed Supplementation

Quorum quenching (QQ) is a promising alternative infection-control strategy to antibiotics that controls quorum-regulated virulence without killing the pathogens. Aeromonas hydrophila is an opportunistic gram-negative pathogen living in freshwater and marine environments. A. hydrophila possesses an N-acyl homoserine lactone (AHL)-based quorum-sensing (QS) system that regulates virulence, so quorum signal-inactivation (i.e., QQ) may represent a new way to combat A. hydrophila infection. In this study, an AHL lactonase gene, aiiA was cloned from Bacillus sp. strain QSI-1 and expressed in Escherichia coli strain BL21(DE3). The A. hydrophila hexanoyl homoserine lactone (C6-HSL) QS signal molecule was degraded by AiiAQSI-1, which resulted in a decrease of bacterial swimming motility, reduction of extracellular protease and hemolysin virulence factors, and inhibited the biofilm formation of A. hydrophila YJ-1 in a microtiter assay. In cell culture studies, AiiAQSI-1 decreased the ability of A. hydrophila adherence to and internalization by Epithelioma papulosum cyprini (EPC) cells. During in vivo studies, oral administration of AiiAQSI-1 via feed supplementation attenuated A. hydrophila infection in Crucian Carp. Results from this work indicate that feed supplementation with AiiAQSI-1 protein has potential to control A. hydrophila aquaculture disease via QQ.

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

Microbiology ◽

10.1099/mic.0.26375-0 ◽

2003 ◽

Vol 149 (8) ◽

pp. 1981-1989 ◽

Cited By ~ 164

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.

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Degradation of N-Acyl-l-Homoserine Lactones by Bacillus cereus in Culture Media and Pork Extract

Applied and Environmental Microbiology ◽

10.1128/aem.01993-06 ◽

2007 ◽

Vol 73 (7) ◽

pp. 2329-2332 ◽

Cited By ~ 29

Author(s):

Maria Stella Medina-Martínez ◽

Mieke Uyttendaele ◽

Andreja Rajkovic ◽

Pol Nadal ◽

Johan Debevere

Keyword(s):

Quorum Sensing ◽

Bacillus Cereus ◽

Yersinia Enterocolitica ◽

Culture Medium ◽

Culture Media ◽

Homoserine Lactone ◽

Microbial Interaction ◽

Signal Molecule ◽

Homoserine Lactones ◽

Degrading Bacterium

ABSTRACT Degradation of the quorum-sensing signal molecule N-acyl-l-homoserine lactone (AHL) in cocultures was verified with Bacillus cereus and Yersinia enterocolitica in culture medium and in pork extract. Results showed evidence of microbial interaction when the AHL-degrading bacterium and AHL-producing bacterium were cocultured in a food-simulating condition.

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Azithromycin Inhibits MUC5AC Production Induced by the Pseudomonas aeruginosa Autoinducer N-(3-Oxododecanoyl) Homoserine Lactone in NCI-H292 Cells

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.48.9.3457-3461.2004 ◽

2004 ◽

Vol 48 (9) ◽

pp. 3457-3461 ◽

Cited By ~ 87

Author(s):

Yoshifumi Imamura ◽

Katsunori Yanagihara ◽

Yohei Mizuta ◽

Masafumi Seki ◽

Hideaki Ohno ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Bacterial Infection ◽

Core Protein ◽

Homoserine Lactone ◽

Signal Molecule ◽

Diffuse Panbronchiolitis ◽

Mucin Production ◽

Protein Levels ◽

Extracellular Signal

ABSTRACT The features of chronic airway diseases, including chronic bronchitis, cystic fibrosis, bronchiectasis, and diffuse panbronchiolitis, include chronic bacterial infection and airway obstruction by mucus. Pseudomonas aeruginosa is one of the most common pathogens in chronic lung infection, and quorum-sensing systems contribute to the pathogenesis of this disease. The quorum-sensing signal molecule [N-(3-oxododecanoyl) homoserine lactone (3O-C12-HSL)] not only regulates bacterial virulence but also is associated with the immune response. In this study, we investigated whether 3O-C12-HSL could stimulate the production of a major mucin core protein, MUC5AC. The effect of a macrolide on MUC5AC production was also studied. 3O-C12-HSL induced NCI-H292 cells to express MUC5AC at both the mRNA and the protein levels in time- and dose-dependent manners. A 15-membered macrolide, azithromycin, inhibited MUC5AC production that was activated by 3O-C12-HSL. 3O-C12-HSL induced extracellular signal-regulated kinase (ERK) 1/2 and I-κB phosphorylation in cells, and this induction was suppressed by azithromycin. 3O-C12-HSL-induced MUC5AC production was blocked by the ERK pathway inhibitor PD98059. Our findings suggest that the P. aeruginosa autoinducer 3O-C12-HSL contributes to excessive mucin production in chronic bacterial infection. Azithromycin seems to reduce this mucin production by interfering with intracellular signal transduction.

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Microbiota on Spoiled Vegetables and Their Characterization

Journal of Food Protection ◽

10.4315/0362-028x.jfp-12-439 ◽

2013 ◽

Vol 76 (8) ◽

pp. 1350-1358 ◽

Cited By ~ 27

Author(s):

DONG HWAN LEE ◽

JIN-BEOM KIM ◽

MIHYUN KIM ◽

EUNJUNG ROH ◽

KYUSUK JUNG ◽

...

Keyword(s):

Plant Cell Wall ◽

Pectate Lyase ◽

Homoserine Lactone ◽

Cell Wall Degrading Enzymes ◽

Biochemical Tests ◽

Signal Molecule ◽

16S Rdna Sequence ◽

Fresh Vegetables ◽

Spoilage Bacteria ◽

Important Enzyme

Spoilage causes vegetables to deteriorate and develop unpleasant characteristics. Approximately 30% of fresh vegetables are lost to spoilage, mainly due to colonization by bacteria. In the present study, a total of 44 bacterial isolates were obtained from a number of spoiled vegetables. The isolates were identified and classified into 20 different species of 14 genera based on fatty acid composition, biochemical tests, and 16S rDNA sequence analyses. Pseudomonas spp. were the species most frequently isolated from the spoiled vegetables. To evaluate the spoilage ability of each species, a variety of fresh vegetables were treated with each isolate and their degree of maceration was observed. In addition, the production of plant cell wall-degrading enzymes (PCWDEs), such as cellulase, xylanase, pectate lyase, and polygalacturonase, was compared among isolates to investigate their potential associations with spoilage. Strains that produce more PCWDEs cause spoilage on more diverse plants, and pectinase may be the most important enzyme among PCWDEs for vegetable spoilage. Most gram-negative spoilage bacteria produced acylated homoserine lactone, a quorum-sensing signal molecule, suggesting that it may be possible to use this compound effectively to prevent or slow down the spoilage of vegetables contaminated with diverse bacteria.

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

Journal of Bacteriology ◽

10.1128/jb.01054-07 ◽

2007 ◽

Vol 189 (22) ◽

pp. 8333-8338 ◽

Cited By ~ 53

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.

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