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


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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    • "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.
    Cell Reports 03/2015; 10(11). DOI:10.1016/j.celrep.2015.02.049 · 8.36 Impact Factor
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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.
    Food Control 12/2014; 45:62–69. DOI:10.1016/j.foodcont.2014.04.024 · 2.81 Impact Factor
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    • "In addition, competitive organisms are able to clear the signal molecule to quench QS (Kalia and Purohit, 2011). For instance, E. coli ingest AI-2s to influence the QS of Vibrio harveyi (Xavier and Bassler, 2005). Bacteria with AHL-degrading activity protect Artemia spp., rotifers and larvae of turbot or prawn from infection (Nhan et al., 2010). "
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    ABSTRACT: It is a common practice for decades to use of sub-therapeutic dose of antibiotics in food-animal feeds to prevent animals from diseases and to improve production performance in modern animal husbandry. In the meantime, concerns over the increasing emergence of antibiotic-resistant bacteria due to the unreasonable use of antibiotics and an appearance of less novelty antibiotics have prompted efforts to develop so-called alternatives to antibiotics. Whether or not the alternatives could really replace antibiotics remains a controversial issue. This review summarizes recent development and perspectives of alternatives to antibiotics. The mechanism of actions, applications, and prospectives of the alternatives such as immunity modulating agents, bacteriophages and their lysins, antimicrobial peptides, pro-, pre-, and synbiotics, plant extracts, inhibitors targeting pathogenicity (bacterial quorum sensing, biofilm, and virulence), and feeding enzymes are thoroughly discussed. Lastly, the feasibility of alternatives to antibiotics is deeply analyzed. It is hard to conclude that the alternatives might substitute antibiotics in veterinary medicine in the foreseeable future. At the present time, prudent use of antibiotics and the establishment of scientific monitoring systems are the best and fastest way to limit the adverse effects of the abuse of antibiotics and to ensure the safety of animal-derived food and environment.
    Frontiers in Microbiology 05/2014; 5:217. DOI:10.3389/fmicb.2014.00217 · 3.99 Impact Factor
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