How Delisea pulchra furanones affect quorum sensing and swarming motility in Serratia liquefaciens MG1

Rasmussen, Trine Bernholdt; Manefield, Michael; Andersen, Jens Bo; Eberl, Leo; Anthoni, Uffe; Christophersen, Carsten; Steinberg, Peter D.; Kjelleberg, Staffan; Givskov, Michael

doi:10.1099/00221287-146-12-3237

Cited by 240 publications

(171 citation statements)

References 32 publications

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“…Interestingly, PA2591 is active as early as OD 600 0?3 and remains active at least up to OD 600 2?7 , indicating that activation of LasR/RhlR requires only minute amounts of AHLs for initiation of PA251 transcription. Most QSI compounds may function in a competitive manner Rasmussen et al, 2005aRasmussen et al, , b, 2000, although a recent analysis with LuxR proteins harbouring mutated amino acids in the AHL-binding cavity shows that furanone compound 30 is not a competitive inhibitor per se (Koch et al, 2005). If this extrapolates to P. aeruginosa there will always be at least some active AHL-receptor proteins regardless of the concentration of QSI compounds.…”

Section: Global Analysis Of Qsi Effectsmentioning

confidence: 99%

Quorum sensing inhibitors: a bargain of effects

2006

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Many opportunistic pathogenic bacteria rely on quorum sensing (QS) circuits as central regulators of virulence expression. In Pseudomonas aeruginosa, QS-regulated gene expression contributes to the formation and maintenance of biofilms and their tolerance to conventional antimicrobials and the host innate immune system. Therefore, QS is an obvious target for a novel class of antimicrobial drugs which would function to efficiently block reception of the cognate QS signals in vivo, and thereby be capable of inducing chemical attenuation of pathogens. As QS is not directly involved in processes essential for growth of the bacteria, inhibition of QS does not impose harsh selective pressure for development of resistance as with antibiotics. Numerous chemical libraries of both natural and synthetic origin have been screened and several QS-inhibitory compounds have been identified. In animal pulmonary infection models, such inhibitors have proven able to significantly improve clearing of the infecting bacteria and reduce mortality. In addition, several enzymes that are able to inactivate the bacterial QS signal molecules have been identified. This inactivation leads to blockage of QS-mediated virulence of plant pathogens in several models. Quorum sensingBacteria are social organisms capable of interacting with each other and their surroundings. Particularly well described is the ability to coordinate gene expression in accordance with population density, a process termed quorum sensing (QS) (Fuqua et al., 1994). In Gram-negative bacteria this is achieved by production and reception of diffusible signal molecules in the form of acylhomoserine lactones (AHLs) (Fig. 1). The signal molecules are produced by an AHL synthase encoded by homologues of the AHL synthase gene luxI, which was first identified in Vibrio fischeri (Engebrecht & Silverman, 1984). At low population densities, luxI is constitutively expressed at a low, basal level. Hence, the AHLs accumulate in the surroundings. The LuxR family of receptor/response regulator proteins perceives the AHLs. At a certain threshold concentration of AHL, the signal molecule forms a complex with the receptor protein, which becomes activated. The activated receptor-signal complex in turn forms dimers or multimers with other activated LuxR-AHL complexes. These dimers or multimers function as transcriptional regulators controlling expression of QS-regulated target genes. The QS paradigm states that transcription of QS target genes is activated at a certain population density (which is proportional to the AHL concentration) known as the 'quorum size' -the number of bacteria required to activate the QS system (Eberl, 1999;Fuqua et al., 1994;Salmond et al., 1995;Parsek et al., 1999). In Pseudomonas aeruginosa, however, recent research has shown that each individual QS-regulated gene possesses its own specific quorum size. There is not a single population density at which all QS genes are activated; rather, different genes are activated at different population densities Wagner et al....

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Section: Global Analysis Of Qsi Effectsmentioning

confidence: 99%

Quorum sensing inhibitors: a bargain of effects

2006

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“…As coordination is a necessity for the colony to further grow, rapidly expand and thereby acquire new sources of nutrients it is an example of a self-organized process. Moreover, the swarmer cells themselves show a high degree of co-operativity that appears to be necessary in order for the motion of the swarmer cells to be useful (Eberl et al, 1996b;Rasmussen et al, 2000;see below).…”

Section: Introductionmentioning

confidence: 99%

Quantitative Effects of Medium Hardness and Nutrient Availability on the Swarming Motility of Serratia liquefaciens

Bees

Andresén

Mosekilde

et al. 2002

Bulletin of Mathematical Biology

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We report the first controlled measurements of expansion rates for swarming colonies of Serratia liquefaciens under different growth conditions, combined with qualitative observations of the organization of the colony into regions of differentiated cell types. Significantly, the results reveal that swarming colonies of S. liquefaciens can have an increasing expansion rate with time. We compare and contrast the expansion rate results with predictions from a recent mathematical model which coupled key hydrodynamical and biological mechanisms. Furthermore, we investigate whether the swarming colonies grow according to a power law or exponentially (for large times), as suggested by recent theoretical results.

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“…Pseudomonas aeruginosa infection mainly cause by the production of mucoid alginate and formation of biofilm in the lungs of patients suffering from cystic fibrosis [79]. Bacterial inhibition mainly occur by inhibiting the furanone on the quorum sensing mechanism by functioning as intracellular signal antagonist, as a result disruption of intra and inter cellular cell-cell communication occur [80]. This effect mainly occur in gram negative bacteria.…”

Section: Antibiotic Activitymentioning

confidence: 99%

Bioactive Compounds and Properties of Seaweeds—A Review

Pal¹,

Kamthania²,

Kumar³

2014

OALib

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In last three decades the discovery of metabolite and biological activities from macroalgae has been increased significantly. Many sophisticated modern research tools are available for making of chemical compound but there are still many natural bioactive compounds in the womb of nature which is a mystery, scientist are still working to find out more biologically active compounds. Bioactive substances from seaweeds currently receive the more attention from the pharmaceutical companies for the drug development as well as the researchers. Seaweeds are taking majority of attention from scientists because of its phenomenon bioactive compounds and its properties like anti-viral, anti-tumor, anti-inflammatory and anti-lipedimic and may more properties. This current review described mainly substances like metabolite, properties, and types of seaweeds. Emphasis is given to main metabolite and properties of seaweeds.

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How Delisea pulchra furanones affect quorum sensing and swarming motility in Serratia liquefaciens MG1

Cited by 240 publications

References 32 publications

Quorum sensing inhibitors: a bargain of effects

Quorum sensing inhibitors: a bargain of effects

Quantitative Effects of Medium Hardness and Nutrient Availability on the Swarming Motility of Serratia liquefaciens

Bioactive Compounds and Properties of Seaweeds—A Review

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