Quorum-sensing regulates biofilm formation in Vibrio scophthalmi

BMC Microbiology

Anicet R Blanch¹  Debra L Milton²  Silvia Melado-Rovira¹  Cristina García-Aljaro¹ 

[1] Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, 08028, Spain;Department of Molecular Biology, Umeå University, Umeå, 90187, Sweden

关键词: Acyl homoserine lactone;    LuxS;    AiiA;    Quorum-sensing;    Biofilm formation;    Vibrio scophthalmi;   

Others  :  1144852
DOI  :  10.1186/1471-2180-12-287

 received in 2012-05-11, accepted in 2012-11-23,  发布年份 2012

【 摘 要 】

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–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.

【 授权许可】

   
2012 Garcia-Aljaro et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

Figure 3.

【 参考文献 】

• [1]Cerda-Cuellar M, Blanch AR: Determination of Vibrio scophthalmi and its phenotypic diversity in turbot larvae. Environ Microbiol 2004, 6(3):209-217.
• [2]Cerda-Cuellar M, Rossello-Mora RA, Lalucat J, Jofre J, Blanch A: Vibrio scophthalmi sp. nov., a new species from turbot (Scophthalmus maximus). Int J Syst Bacteriol 1997, 47(1):58-61.
• [3]Fuqua WC, Winans SC, Greenberg EP: Quorum sensing in bacteria: the LuxR-LuxI family of cell density-responsive transcriptional regulators. J Bacteriol 1994, 176(2):269-275.
• [4]Engebrecht J, Silverman M: Identification of genes and gene products necessary for bacterial bioluminescence. Proc Natl Acad Sci USA 1984, 81(13):4154-4158.
• [5]Nealson KH, Platt T, Hastings JW: Cellular control of the synthesis and activity of the bacterial luminescent system. J Bacteriol 1970, 104(1):313-322.
• [6]Lerat E, Moran NA: The evolutionary history of quorum-sensing systems in bacteria. Mol Biol Evol 2004, 21(5):903-913.
• [7]Milton DL: Quorum sensing in vibrios: complexity for diversification. Int J Med Microbiol 2006, 296(2–3):61-71.
• [8]Chen X, Schauder S, Potier N, Van Dorsselaer A, Pelczer I, Bassler BL, Hughson FM: Structural identification of a bacterial quorum-sensing signal containing boron. Nature 2002, 415(6871):545-549.
• [9]Higgins DA, Pomianek ME, Kraml CM, Taylor RK, Semmelhack MF, Bassler BL: The major Vibrio cholerae autoinducer and its role in virulence factor production. Nature 2007, 450(7171):883-886.
• [10]Miller MB, Bassler BL: Quorum sensing in bacteria. Annu Rev Microbiol 2001, 55:165-199.
• [11]Garcia-Aljaro C, Eberl L, Riedel K, Blanch AR: Detection of quorum-sensing-related molecules in Vibrio scophthalmi. BMC Microbiol 2008, 8:138. BioMed Central Full Text
• [12]Ramos JL, Martinez-Bueno M, Molina-Henares AJ, Teran W, Watanabe K, Zhang X, Gallegos MT, Brennan R, Tobes R: The TetR family of transcriptional repressors. Microbiol Mol Biol Rev 2005, 69(2):326-356.
• [13]Hasegawa H, Hase CC: TetR-type transcriptional regulator VtpR functions as a global regulator in Vibrio tubiashii. Appl Environ Microbiol 2009, 75:7602-7609.
• [14]McCarter LL: OpaR, a homolog of Vibrio harveyi LuxR, controls opacity of Vibrio parahaemolyticus. J Bacteriol 1998, 180(12):3166-3173.
• [15]McDougald D, Rice SA, Kjelleberg S: The marine pathogen Vibrio vulnificus encodes a putative homologue of the Vibrio harveyi regulatory gene, luxR: a genetic and phylogenetic comparison. Gene 2000, 248(1–2):213-221.
• [16]Kovacikova G, Skorupski K: Regulation of virulence gene expression in Vibrio cholerae by quorum sensing: HapR functions at the aphA promoter. Mol Microbiol 2002, 46(4):1135-1147.
• [17]Croxatto A, Chalker VJ, Lauritz J, Jass J, Hardman A, Williams P, Camara M, Milton DL: VanT, a homologue of Vibrio harveyi LuxR, regulates serine, metalloprotease, pigment, and biofilm production in Vibrio anguillarum. J Bacteriol 2002, 184(6):1617-1629.
• [18]Li X, Han Y, Yang Q, Zhang XH: Detection of quorum sensing signal molecules and mutation of luxS gene in Vibrio ichthyoenteri. Res Microbiol 2010, 161(1):51-57.
• [19]Schembri MA, Givskov M, Klemm P: An attractive surface: gram-negative bacterial biofilms. Sci STKE 2002, 2002(132):re6.
• [20]Zhu J, Miller MB, Vance RE, Dziejman M, Bassler BL, et al.: Quorum-sensing regulators control virulence gene expression in Vibrio cholerae. Proc Natl Acad Sci USA 2002, 99:3129-3134.
• [21]Lilley BN, Bassler BL: Regulation of quorum sensing in Vibrio harveyi by LuxO and sigma-54. Mol Microbiol 2000, 36(4):940-954.
• [22]Wang Q, Liu Q, Ma Y, Rui H, Zhang Y: LuxO controls extracellular protease, haemolytic activities and siderophore production in fish pathogen Vibrio alginolyticus. J Appl Microbiol 2007, 103:1525-1534.
• [23]Graf J, Ruby EG: Novel effects of a transposon insertion in the Vibrio fischeri glnD gene: defects in iron uptake and symbiotic persistence in addition to nitrogen utilization. Mol Microbiol 2000, 37:168-179.
• [24]Mok KC, Wingreen NS, Bassler BL: Vibrio harveyi quorum sensing: a coincidence detector for two autoinducers controls gene expression. EMBO J 2003, 22(4):870-881.
• [25]Henke JM, Bassler BL: Quorum sensing regulates type III secretion in Vibrio harveyi and Vibrio parahaemolyticus. J Bacteriol 2004, 186(12):3794-3805.
• [26]Garcia-Aljaro C, Muniesa M, Jofre J, Blanch AR: Prevalence of the stx2 gene in coliform populations from aquatic environments. Appl Environ Microbiol 2004, 70(6):3535-3540.
• [27]Ochman H, Gerber AS, Hartl DL: Genetic applications of an inverse polymerase chain reaction. Genetics 1988, 120:621-623.
• [28]Milton DL, O'Toole R, Horstedt P, Wolf-Watz H: Flagellin A is essential for the virulence of Vibrio anguillarum. J Bacteriol 1996, 178(5):1310-1319.
• [29]Denkin SM, Nelson DR: Induction of protease activity in Vibrio anguillarum by gastrointestinal mucus. Appl Environ Microbiol 1999, 65(8):3555-3560.
• [30]Stepanovic S, Vukovic D, Hola V, Di Bonaventura G, Djukic S, Cirkovic I, Ruzicka F: Quantification of biofilm in microtiter plates: overview of testing conditions and practical recommendations for assessment of biofilm production by staphylococci. APMIS 2007, 115(8):891-899.
• [31]Schwyn B, Neilands JB: Universal chemical assay for the detection and determination of siderophores. Anal Biochem 1987, 160(1):47-56.
• [32]Miller VL, Mekalanos JJ: A novel suicide vector and its use in construction of insertion mutations: osmoregulation of outer membrane proteins and virulence determinants in Vibrio cholerae requires toxR. J Bacteriol 1988, 170(6):2575-2583.
• [33]Morales VM, Backman A, Bagdasarian M: A series of wide-host-range low-copy-number vectors that allow direct screening for recombinants. Gene 1991, 97(1):39-47.
• [34]Rose RE: The nucleotide sequence of pACYC184. Nucleic Acids Res Microbiol 1988, 16:355.