Quorum-sensing regulates biofilm formation in <it>Vibrio scophthalmi</it>
<p>Abstract</p> <p>Background</p> <p>In a previous study, we demonstrated that <it>Vibrio scophthalmi</it>, the most abundant <it>Vibrio</it> species among the marine aerobic or facultatively anaerobic bacteria inhabiting the intestinal tract of...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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BMC
2012-12-01
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| Series: | BMC Microbiology |
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| Online Access: | http://www.biomedcentral.com/1471-2180/12/287 |
| _version_ | 1811246092051808256 |
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| author | García-Aljaro Cristina Melado-Rovira Silvia Milton Debra L Blanch Anicet R |
| author_facet | García-Aljaro Cristina Melado-Rovira Silvia Milton Debra L Blanch Anicet R |
| author_sort | García-Aljaro Cristina |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>In a previous study, we demonstrated that <it>Vibrio scophthalmi</it>, the most abundant <it>Vibrio</it> species among the marine aerobic or facultatively anaerobic bacteria inhabiting the intestinal tract of healthy cultured turbot (<it>Scophthalmus maximus</it>), 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 <it>luxS</it>). 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.</p> <p>Results</p> <p>The presence of a homologue to the <it>Vibrio harveyi luxR</it> gene encoding a main transcriptional regulator, whose expression is modulated by quorum–sensing signal molecules in other vibrios, was detected and sequenced. The <it>V. scophthalmi</it> LuxR protein displayed a maximum amino acid identity of 82% with SmcR, the LuxR homologue found in <it>Vibrio vulnificus</it>. <it>luxR</it> and <it>luxS</it> null mutants were constructed and their phenotype analysed. Both mutants displayed reduced biofilm formation <it>in vitro</it> as well as differences in membrane protein expression by mass-spectrometry analysis. Additionally, a recombinant strain of <it>V. scophthalmi</it> carrying the lactonase AiiA from <it>Bacillus cereus</it>, which causes hydrolysis of acyl homoserine lactones, was included in the study.</p> <p>Conclusions</p> <p><it>V. scophthalmi</it> shares two quorum sensing circuits, including the main transcriptional regulator <it>luxR</it>, with some pathogenic vibrios such as <it>V. harveyi</it> and <it>V. anguillarum</it>. 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 <it>luxS</it> and <it>luxR</it> 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.</p> |
| first_indexed | 2024-04-12T14:48:40Z |
| format | Article |
| id | doaj.art-2465255c5ac740bd96e61d2a5347daa0 |
| institution | Directory Open Access Journal |
| issn | 1471-2180 |
| language | English |
| last_indexed | 2024-04-12T14:48:40Z |
| publishDate | 2012-12-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Microbiology |
| spelling | doaj.art-2465255c5ac740bd96e61d2a5347daa02022-12-22T03:28:33ZengBMCBMC Microbiology1471-21802012-12-0112128710.1186/1471-2180-12-287Quorum-sensing regulates biofilm formation in <it>Vibrio scophthalmi</it>García-Aljaro CristinaMelado-Rovira SilviaMilton Debra LBlanch Anicet R<p>Abstract</p> <p>Background</p> <p>In a previous study, we demonstrated that <it>Vibrio scophthalmi</it>, the most abundant <it>Vibrio</it> species among the marine aerobic or facultatively anaerobic bacteria inhabiting the intestinal tract of healthy cultured turbot (<it>Scophthalmus maximus</it>), 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 <it>luxS</it>). 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.</p> <p>Results</p> <p>The presence of a homologue to the <it>Vibrio harveyi luxR</it> gene encoding a main transcriptional regulator, whose expression is modulated by quorum–sensing signal molecules in other vibrios, was detected and sequenced. The <it>V. scophthalmi</it> LuxR protein displayed a maximum amino acid identity of 82% with SmcR, the LuxR homologue found in <it>Vibrio vulnificus</it>. <it>luxR</it> and <it>luxS</it> null mutants were constructed and their phenotype analysed. Both mutants displayed reduced biofilm formation <it>in vitro</it> as well as differences in membrane protein expression by mass-spectrometry analysis. Additionally, a recombinant strain of <it>V. scophthalmi</it> carrying the lactonase AiiA from <it>Bacillus cereus</it>, which causes hydrolysis of acyl homoserine lactones, was included in the study.</p> <p>Conclusions</p> <p><it>V. scophthalmi</it> shares two quorum sensing circuits, including the main transcriptional regulator <it>luxR</it>, with some pathogenic vibrios such as <it>V. harveyi</it> and <it>V. anguillarum</it>. 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 <it>luxS</it> and <it>luxR</it> 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.</p>http://www.biomedcentral.com/1471-2180/12/287Vibrio scophthalmiBiofilm formationQuorum-sensingAiiALuxSAcyl homoserine lactone |
| spellingShingle | García-Aljaro Cristina Melado-Rovira Silvia Milton Debra L Blanch Anicet R Quorum-sensing regulates biofilm formation in <it>Vibrio scophthalmi</it> BMC Microbiology Vibrio scophthalmi Biofilm formation Quorum-sensing AiiA LuxS Acyl homoserine lactone |
| title | Quorum-sensing regulates biofilm formation in <it>Vibrio scophthalmi</it> |
| title_full | Quorum-sensing regulates biofilm formation in <it>Vibrio scophthalmi</it> |
| title_fullStr | Quorum-sensing regulates biofilm formation in <it>Vibrio scophthalmi</it> |
| title_full_unstemmed | Quorum-sensing regulates biofilm formation in <it>Vibrio scophthalmi</it> |
| title_short | Quorum-sensing regulates biofilm formation in <it>Vibrio scophthalmi</it> |
| title_sort | quorum sensing regulates biofilm formation in it vibrio scophthalmi it |
| topic | Vibrio scophthalmi Biofilm formation Quorum-sensing AiiA LuxS Acyl homoserine lactone |
| url | http://www.biomedcentral.com/1471-2180/12/287 |
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