scholarly journals Detection of Diverse N-Acyl-Homoserine Lactones in Vibrio alginolyticus and Regulation of Biofilm Formation by N-(3-Oxodecanoyl) Homoserine Lactone In vitro

2017 ◽  
Vol 8 ◽  
Author(s):  
Jianfei Liu ◽  
Kaifei Fu ◽  
Yuxiao Wang ◽  
Chenglin Wu ◽  
Fei Li ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Homoserine Lactone ◽  
Vibrio Alginolyticus ◽  
Homoserine Lactones ◽  
Acyl Homoserine Lactones

scholarly journals Two Dissimilar N-Acyl-Homoserine Lactone Acylases of Pseudomonas syringae Influence Colony and Biofilm Morphology

2008 ◽  
Vol 75 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Ryan W. Shepherd ◽  
Steven E. Lindow
Keyword(s):  
Pseudomonas Syringae ◽  
Biofilm Formation ◽  
Homoserine Lactone ◽  
Acyl Homoserine Lactone ◽  
Associated Bacteria ◽  
Homoserine Lactones ◽  
Amide Bonds ◽  
Acyl Homoserine Lactones ◽  
Complex Habitat ◽  
Long Chain

ABSTRACT Plant aerial surfaces comprise a complex habitat for microorganisms, and many plant-associated bacteria, such as the pathogen Pseudomonas syringae, exhibit density-dependent survival on leaves by utilizing quorum sensing (QS). QS is often mediated by diffusible signals called N-acyl-homoserine lactones (AHLs), and P. syringae utilizes N-3-oxo-hexanoyl-dl-homoserine lactone (3OC6HSL) to control traits influencing epiphytic fitness and virulence. The P. syringae pathovar syringae B728a genome sequence revealed two putative AHL acylases, termed HacA (Psyr_1971) and HacB (Psyr_4858), which are N-terminal nucleophile hydrolases that inactivate AHLs by cleaving their amide bonds. HacA is a secreted AHL acylase that degrades only long-chain (C ≥ 8) AHLs, while HacB is not secreted and degrades all tested AHLs. Targeted disruptions of hacA, hacB, and hacA and hacB together do not alter endogenous 3OC6HSL levels under the tested conditions. Surprisingly, targeted disruptions of hacA alone and hacA and hacB together confer complementable phenotypes that are very similar to autoaggregative phenotypes seen in other species. While AHL acylases might enable P. syringae B728a to degrade signals of competing species and block expression of their QS-dependent traits, these enzymes also play fundamental roles in biofilm formation.

scholarly journals Induction of Neutrophil Chemotaxis by the Quorum-Sensing Molecule N-(3-Oxododecanoyl)-l-Homoserine Lactone

2006 ◽  
Vol 74 (10) ◽  
pp. 5687-5692 ◽  
Author(s):  
Sabine Zimmermann ◽  
Christof Wagner ◽  
Wencke Müller ◽  
Gerald Brenner-Weiss ◽  
Friederike Hug ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Signaling Pathway ◽  
Biofilm Formation ◽  
Homoserine Lactone ◽  
Polymorphonuclear Neutrophils ◽  
Mitogen Activated Protein Kinase ◽  
Homoserine Lactones ◽  
Kinase C ◽  
Acyl Homoserine Lactones

ABSTRACT Acyl homoserine lactones are synthesized by Pseudomonas aeruginosa as signaling molecules which control production of virulence factors and biofilm formation in a paracrine manner. We found that N-(3-oxododecanoyl)-l-homoserine lactone (3OC12-HSL), but not its 3-deoxo isomer or acyl-homoserine lactones with shorter fatty acids, induced the directed migration (chemotaxis) of human polymorphonuclear neutrophils (PMN) in vitro. By use of selective inhibitors a signaling pathway, comprising phosphotyrosine kinases, phospholipase C, protein kinase C, and mitogen-activated protein kinase C, could be delineated. In contrast to the well-studied chemokines complement C5a and interleukin 8, the chemotaxis did not depend on pertussis toxin-sensitive G proteins, indicating that 3OC12-HSL uses another signaling pathway. Strong evidence for the presence of a receptor for 3OC12-HSL on PMN was derived from uptake studies; by use of radiolabeled 3OC12-HSL, specific and saturable binding to PMN was seen. Taken together, our data provide evidence that PMN recognize and migrate toward a source of 3OC12-HSL (that is, to the site of a developing biofilm). We propose that this early attraction of PMN could contribute to prevention of biofilm formation.

Characterization of the in vitro production of N-acyl homoserine lactones by cultivable bacteria inhabiting the sponge Suberites domuncula

2016 ◽  
Vol 97 (1) ◽  
pp. 119-127
Author(s):  
Jasnizat Bin Saidin ◽  
Mohd Effendy Abd Wahid ◽  
Gaël Le Pennec
Keyword(s):  
In Vitro Production ◽  
Form Complex ◽  
Suberites Domuncula ◽  
Associated Bacteria ◽  
Homoserine Lactones ◽  
Cultivable Bacteria ◽  
Acyl Homoserine Lactones ◽  
Vitro Production

Sponges together with associated bacteria form complex holobionts governed by various relationships established between the partners. Molecules of communication may participate in the homeostasis of these biological associations. Bacteria produce N-acyl homoserine lactones to communicate. In the present study, we characterized 102 cultivable bacteria isolated from the sponge Suberites domuncula at the genus level and described their production of AHLs during 96 h of culture in a Marine Broth medium. The presence of AHLs was monitored using the Escherichia coli pSB406 reporter strain. Sixty-seven bacteria were AHLs positive. Among them, 46 were related to the Gammaproteobacteria, eight to the Alphaproteobacteria, seven to the Firmicutes and six to the Flavobacteria. The kinetic production of AHLs was determined and compared with a reference bacterium, Pseudomonas aeruginosa PAO1 (pDA224). We established three profiles of AHLs production with no definitive pattern related to an order, a family or a genus of bacteria.

scholarly journals Ethanolic leaf extracts of Waru (Hibiscus tiliaceus) inhibit biofilm formation of Vibrio alginolyticus in vitro

2019 ◽  
Vol 1321 ◽  
pp. 032045
Author(s):  
S Suhartono ◽  
L Fitri ◽  
N Nurhaliza ◽  
Y S Ismail ◽  
R Nursanty ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Vibrio Alginolyticus ◽  
Leaf Extracts

scholarly journals Mutation of luxS Affects Biofilm Formation in Streptococcus mutans

2003 ◽  
Vol 71 (4) ◽  
pp. 1972-1979 ◽  
Author(s):  
Justin Merritt ◽  
Fengxia Qi ◽  
Steven D. Goodman ◽  
Maxwell H. Anderson ◽  
Wenyuan Shi
Keyword(s):  
Quorum Sensing ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Microscopic Analysis ◽  
Homoserine Lactone ◽  
Good Evidence ◽  
Genome Project ◽  
Bacterial Biofilm ◽  
Wild Type

ABSTRACT Quorum sensing is a bacterial mechanism for regulating gene expression in response to changes in population density. Many bacteria are capable of acyl-homoserine lactone-based or peptide-based intraspecies quorum sensing and luxS-dependent interspecies quorum sensing. While there is good evidence about the involvement of intraspecies quorum sensing in bacterial biofilm, little is known about the role of luxS in biofilm formation. In this study, we report for the first time that luxS-dependent quorum sensing is involved in biofilm formation of Streptococcus mutans. S. mutans is a major cariogenic bacterium in the multispecies bacterial biofilm commonly known as dental plaque. An ortholog of luxS for S. mutans was identified using the data available in the S. mutans genome project (http://www.genome.ou.edu/smutans.html ). Using an assay developed for the detection of the LuxS-associated quorum sensing signal autoinducer 2 (AI-2), it was demonstrated that this ortholog was able to complement the luxS negative phenotype of Escherichia coli DH5α. It was also shown that AI-2 is indeed produced by S. mutans. AI-2 production is maximal during mid- to late-log growth in batch culture. Mutant strains devoid of the luxS gene were constructed and found to be defective in producing the AI-2 signal. There are also marked phenotypic differences between the wild type and the luxS mutants. Microscopic analysis of in vitro-grown biofilm structure revealed that the luxS mutant biofilms adopted a much more granular appearance, rather than the relatively smooth, confluent layer normally seen in the wild type. These results suggest that LuxS-dependent signal may play an important role in biofilm formation of S. mutans.

scholarly journals Effects of Exogenous N-Acyl-Homoserine Lactones on Biofilm Formation and Motility in Acinetobacter nosocomialis

2020 ◽  
Vol 50 (2) ◽  
pp. 97-106
Author(s):  
Surya Surendran ◽  
Bindu Subhadra ◽  
Kyungho Woo ◽  
Ho Sung Park ◽  
Dong Ho Kim ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Homoserine Lactones ◽  
Acyl Homoserine Lactones

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 Metabolism of Acyl-Homoserine Lactone Quorum-Sensing Signals by Variovorax paradoxus

2000 ◽  
Vol 182 (24) ◽  
pp. 6921-6926 ◽  
Author(s):  
Jared R. Leadbetter ◽  
E. P. Greenberg
Keyword(s):  
Energy Source ◽  
Nitrogen Sources ◽  
Homoserine Lactone ◽  
Sole Source ◽  
Acyl Homoserine Lactone ◽  
Homoserine Lactones ◽  
Variovorax Paradoxus ◽  
Acyl Homoserine Lactones ◽  
Quorum Sensing Signals ◽  
Sole Energy

ABSTRACT Acyl-homoserine lactones (acyl-HSLs) serve as dedicated cell-to-cell signaling molecules in many species of the classProteobacteria. We have addressed the question of whether these compounds can be degraded biologically. A motile, rod-shaped bacterium was isolated from soil based upon its ability to utilizeN-(3-oxohexanoyl)-l-homoserine lactone as the sole source of energy and nitrogen. The bacterium was classified as a strain of Variovorax paradoxus. TheV. paradoxus isolate was capable of growth on all of the acyl-HSLs tested. The molar growth yields correlated with the length of the acyl group. HSL, a product of acyl-HSL metabolism, was used as a nitrogen source, but not as an energy source. Cleavage and partial mineralization of the HSL ring were demonstrated by using radiolabeled substrate. This study indicates that some strains of V. paradoxus degrade and grow on acyl-HSL signals as the sole energy and nitrogen sources. This study provides clues about the metabolic pathway of acyl-HSL degradation by V. paradoxus.

scholarly journals Marine-Source Quorum Quenching Enzyme YtnP to Improve Hygiene Quality in Dental Units

Marine Drugs ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 225
Author(s):  
Xiaohui Sun ◽  
Philip Hill ◽  
Jia Liu ◽  
Jing Qian ◽  
Yuting Ma ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Quorum Quenching ◽  
Bacillus Velezensis ◽  
Antifouling Activity ◽  
Homoserine Lactones ◽  
Water Filter ◽  
E Coli ◽  
Acyl Homoserine Lactones ◽  
Dental Practitioners ◽  
Marine Source

Biofilm in dental unit water lines may pose a health risk to patients and dental practitioners. An AdiC-like quorum quenching enzyme, YtnP, was cloned from a deep-sea probiotic Bacillus velezensis, and heterologously expressed in E. coli to examine the application on the improvement of hygiene problems caused by biofilm infection of Pseudomonas aeruginosa in dental units. Pseudomonas bacteria were isolated from dental chair units and used to grow static biofilms in the laboratory. A water filter system was designed to test the antifouling activity of YtnP in Laboratory, to simulate the biofilm contamination on water filter in dental unit water lines. The results demonstrated that the enzyme of YtnP was able to degrade the N-acyl homoserine lactones, significantly inhibited the EPS generation, biofilm formation, and virulence factors production (pyocyanin and rhamnolipid) of P. aeruginosa, and was efficient on the antifouling against P. aeruginosa. The findings in this study indicated the possibility of YtnP as novel disinfectant reagent for hygiene treatment in dental units.

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