Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/33706
Title: Quorum-sensing regulates biofilm formation in Vibrio scophthalmi
Author: García Aljaro, Cristina
Melado Rovira, Silvia
Milton, Debra L.
Blanch i Gisbert, Anicet
Keywords: Microbiologia marina
Bacteris patògens
Marine microbiology
Pathogenic bacteria
Issue Date: 3-Dec-2012
Publisher: BioMed Central
Abstract: Background: In a previous study, we demonstrated that Vibrio scophthalmi, the most abundant Vibrio species among the marine aerobic or facultatively anaerobic bacteria inhabiting the intestinal tract of healthy cultured turbot (Scophthalmus maximus), contains at least two quorum-sensing circuits involving two types of signal molecules (a 3-hydroxy-dodecanoyl-homoserine lactone and the universal autoinducer 2 encoded by luxS). The purpose of this study was to investigate the functions regulated by these quorum sensing circuits in this vibrio by constructing mutants for the genes involved in these circuits. Results. The presence of a homologue to the Vibrio harveyi luxR gene encoding a main transcriptional regulator, whose expression is modulated by quorum<br>sensing signal molecules in other vibrios, was detected and sequenced. The V. scophthalmi LuxR protein displayed a maximum amino acid identity of 82% with SmcR, the LuxR homologue found in Vibrio vulnificus. luxR and luxS null mutants were constructed and their phenotype analysed. Both mutants displayed reduced biofilm formation in vitro as well as differences in membrane protein expression by mass-spectrometry analysis. Additionally, a recombinant strain of V. scophthalmi carrying the lactonase AiiA from Bacillus cereus, which causes hydrolysis of acyl homoserine lactones, was included in the study. Conclusions: V. scophthalmi shares two quorum sensing circuits, including the main transcriptional regulator luxR, with some pathogenic vibrios such as V. harveyi and V. anguillarum. However, contrary to these pathogenic vibrios no virulence factors (such as protease production) were found to be quorum sensing regulated in this bacterium. Noteworthy, biofilm formation was altered in luxS and luxR mutants. In these mutants a different expression profile of membrane proteins were observed with respect to the wild type strain suggesting that quorum sensing could play a role in the regulation of the adhesion mechanisms of this bacterium.
Note: Reproducció del document publicat a: http://dx.doi.org/10.1186/1471-2180-12-287
It is part of: Bmc Microbiology, 2012, vol. 12, p. 287
Related resource: http://dx.doi.org/10.1186/1471-2180-12-287
URI: http://hdl.handle.net/2445/33706
ISSN: 1471-2180
Appears in Collections:Articles publicats en revistes (Genètica, Microbiologia i Estadística)

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