Article

Xavier KB, Bassler BL.. Interference with AI-2-mediated bacterial cell-cell communication. Nature 437: 750-753

Department of Molecular Biology, Howard Hughes Medical Institute, Princeton University, Princeton, New Jersey 08544-1014, USA.
Nature (Impact Factor: 41.46). 10/2005; 437(7059):750-3. DOI: 10.1038/nature03960
Source: PubMed

ABSTRACT

Bacteria communicate by means of chemical signal molecules called autoinducers. This process, called quorum sensing, allows bacteria to count the members in the community and to alter gene expression synchronously across the population. Quorum-sensing-controlled processes are often crucial for successful bacterial--host relationships--both symbiotic and pathogenic. Most quorum-sensing autoinducers promote intraspecies communication, but one autoinducer, called AI-2, is produced and detected by a wide variety of bacteria and is proposed to allow interspecies communication. Here we show that some species of bacteria can manipulate AI-2 signalling and interfere with other species' ability to assess and respond correctly to changes in cell population density. AI-2 signalling, and the interference with it, could have important ramifications for eukaryotes in the maintenance of normal microflora and in protection from pathogenic bacteria.

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    • "AI-2, which represents a universal " language " to facilitate interspecies communication, is a byproduct of the detoxification of S-adenosylmethionine (SAM), which is catalyzed by Sribosylhomocysteine lyase (LuxS, EC 4.4.1.21) (Xavier and Bassler, 2005a; Lowery et al., 2008). Studies of the recognition and signal transduction of AI-2 have focused primarily on the LuxP-based system of V. harveyi (Neiditch et al., 2005; Defoirdt et al., 2008) and LasB-based systems of E. coli (Xavier and Bassler, 2005b) and Salmonella sp. "
    Dataset: Review

    Full-text · Dataset · Jan 2016
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    • "By internalizing and processing AI-2 produced by itself as well as from other species, Lsr system-expressing bacteria can disrupt the ability of neighboring species to correctly determine population density and regulate AI-2-dependent behavior appropriately , as shown in vitro in mixed cultures of E. coli and Vibrio spp. (Xavier and Bassler, 2005a). As a result, this system has been explored as a potential means for AI-2 interspecies quorum quenching (Roy et al., 2010). "
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    ABSTRACT: The mammalian gut microbiota harbors a diverse ecosystem where hundreds of bacterial species interact with each other and their host. Given that bacteria use signals to communicate and regulate group behaviors (quorum sensing), we asked whether such communication between different commensal species can influence the interactions occurring in this environment. We engineered the enteric bacterium, Escherichia coli, to manipulate the levels of the interspecies quorum sensing signal, autoinducer-2 (AI-2), in the mouse intestine and investigated the effect upon antibiotic-induced gut microbiota dysbiosis. E. coli that increased intestinal AI-2 levels altered the composition of the antibiotic-treated gut microbiota, favoring the expansion of the Firmicutes phylum. This significantly increased the Firmicutes/Bacteroidetes ratio, to oppose the strong effect of the antibiotic, which had almost cleared the Firmicutes. This demonstrates that AI-2 levels influence the abundance of the major phyla of the gut microbiota, the balance of which is known to influence human health. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
    Preview · Article · Mar 2015 · Cell Reports
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    • "However, it has been shown that bacteria possess not only an intra-species but also an inter-species signalling system (Bassler & Losick, 2006; Hughes & Sperandio, 2008). One of the primary bacterial inter-species communication mechanisms is by the luxS-mediated universal signalling system using autoinducer-2 (AI-2) as signalling molecule (Xavier & Bassler, 2005b), with a luxS homologue typical of multiple bacterial species (Pereira, Thompson, & Xavier, 2012). For example, Escherichia coli, Staphylococcus aureus and Listeria monocytogenes use the LuxS/AI-2 signal for regulation of biofilm formation (Miller & Basler, 2001; Pereira et al., 2012; Xavier & Bassler, 2005a). "
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    ABSTRACT: Bacteria use quorum sensing (QS) to regulate the expression of certain target genes for social behaviour. A LuxS/AI-2 signalling system serves to control the virulence of some pathogenic bacteria by mechanisms such as motility, biofilm formation and attachment, and is typical of the enterohaemorrhagic Escherichia coli O157:H7 (EHEC) associated with infections of the human intestine. The LuxS/AI-2 signalling system presents an interesting potential as antimicrobial target for appropriate AI-2 inhibitors, and thus widens the scope for treatment or prevention of infections by pathogens such as EHEC. Probiotic lactic acid bacteria (LAB) are primary candidates for this approach because of their general acceptability, safety and adaptation to the intestinal and/or food ecosystem. In this paper, we report on Lactobacillus sakei NR28 as a new candidate strain for AI-2 related quorum quenching. It is considered to be a putative probiotic strain and was originally isolated from kimchi, a traditional Korean fermented food known for its special health features. This study has shown that AI-2 activity and the associated virulence factors of the EHEC ‘wild-type’ strain E. coli ATCC 43894, were significantly reduced by L. sakei NR28, while, at the same time, the cell viability of the EHEC strain was not affected. In addition, the purified AI-2 molecule, a luxS-deficient mutant of EHEC strain ATCC 43894, and an AI-2 independent EHEC mimicking strain of Citrobacter rodentium were used to determine the relationship between the virulence reducing effect of L. sakei NR28 and its AI-2 inhibiting ability. Our results showed that L. sakei NR28 has a reducing effect on the pathogenicity of the ‘wild-type’ EHEC strain ATCC 43894 by AI-2 signalling inhibition.
    Full-text · Article · Dec 2014 · Food Control
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