title: A genomic region involved in the formation of adhesin fibers in Bacillus cereus biofilms.
abstract: Bacillus cereus is a bacterial pathogen that is responsible for many recurrent disease outbreaks due to food contamination. Spores and biofilms are considered the most important reservoirs of B. cereus in contaminated fresh vegetables and fruits. Biofilms are bacterial communities that are difficult to eradicate from biotic and abiotic surfaces because of their stable and extremely strong extracellular matrix. These extracellular matrixes contain exopolysaccharides, proteins, extracellular DNA, and other minor components. Although B. cereus can form biofilms, the bacterial features governing assembly of the protective extracellular matrix are not known. Using the well-studied bacterium B. subtilis as a model, we identified two genomic loci in B. cereus, which encodes two orthologs of the amyloid-like protein TasA of B. subtilis and a SipW signal peptidase. Deletion of this genomic region in B. cereus inhibited biofilm assembly; notably, mutation of the putative signal peptidase SipW caused the same phenotype. However, mutations in tasA or calY did not completely prevent biofilm formation; strains that were mutated for either of these genes formed phenotypically different surface attached biofilms. Electron microscopy studies revealed that TasA polymerizes to form long and abundant fibers on cell surfaces, whereas CalY does not aggregate similarly. Heterologous expression of this amyloid-like cassette in a B. subtilis strain lacking the factors required for the assembly of TasA amyloid-like fibers revealed (i) the involvement of this B. cereus genomic region in formation of the air-liquid interphase pellicles and (ii) the intrinsic ability of TasA to form fibers similar to the amyloid-like fibers produced by its B. subtilis ortholog.
authors: Departamento de Microbiología, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga Málaga, Spain.
authors: Joaquín
authors: J
authors: Caro-Astorga
authors: Departamento de Microbiología, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga Málaga, Spain.
authors: Alejandro
authors: A
authors: Pérez-García
authors: Departamento de Microbiología, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga Málaga, Spain.
authors: Antonio
authors: A
authors: de Vicente
authors: Departamento de Microbiología, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga Málaga, Spain.
authors: Diego
authors: D
authors: Romero
keywords: Bacillus cereus; amyloid; biofilm formation; extracellular matrix; food-borne pathogens
references: Mol Microbiol. 2012 Jul;85(1):51-66
references: 22571672
references: Food Microbiol. 2010 May;27(3):347-55
references: 20227599
references: J Bacteriol. 2004 Jun;186(12):3970-9
references: 15175311
references: Biochim Biophys Acta. 2001 Sep 28;1537(2):132-46
references: 11566257
references: Mol Microbiol. 2006 Feb;59(4):1216-28
references: 16430695
references: Appl Environ Microbiol. 2009 Oct;75(20):6616-8
references: 19648377
references: Mol Microbiol. 2006 Feb;59(4):1229-38
references: 16430696
references: Antonie Van Leeuwenhoek. 2000 May;77(4):393-9
references: 10959569
references: J Bacteriol. 2014 Apr;196(8):1505-13
references: 24488317
references: Euro Surveill. 2011 Apr 14;16(15):null
references: 21507320
references: J Ind Microbiol Biotechnol. 2001 Aug;27(2):104-10
references: 11641768
references: Mol Microbiol. 2009 Sep;73(6):1128-40
references: 19682261
references: Science. 2002 Feb 1;295(5556):851-5
references: 11823641
references: Mol Microbiol. 2010 Aug;77(3):549-61
references: 20545856
references: Food Microbiol. 2011 Dec;28(8):1441-7
references: 21925026
references: PLoS One. 2011 Apr 19;6(4):e18839
references: 21526199
references: J Bacteriol. 2013 Jun;195(12 ):2747-54
references: 23564171
references: Methods Enzymol. 1999;310:91-109
references: 10547784
references: Appl Microbiol Biotechnol. 2011 Feb;89(4):1161-75
references: 20936277
references: Microbiology. 2010 Apr;156(Pt 4):1009-18
references: 20035003
references: Trends Microbiol. 2005 Jan;13(1):20-6
references: 15639628
references: J Biol Chem. 2012 Oct 12;287(42):35092-103
references: 22891247
references: J Bacteriol. 2008 Sep;190(17):5879-89
references: 18586935
references: Proc Natl Acad Sci U S A. 2001 Sep 25;98(20):11621-6
references: 11572999
references: Structure. 2010 Oct 13;18(10):1244-60
references: 20947013
references: Genes Dev. 1998 Aug 1;12(15):2318-31
references: 9694797
references: Appl Environ Microbiol. 2006 Jul;72(7):5089-92
references: 16820512
references: Genes Dev. 2009 Jul 15;23(14):1631-8
references: 19605685
references: Mol Microbiol. 2011 Jun;80(5):1155-68
references: 21477127
references: Res Microbiol. 2013 Sep;164(7):788-98
references: 23791621
references: Trends Microbiol. 2012 Feb;20(2):66-73
references: 22197327
references: Mol Microbiol. 2008 May;68(4):947-58
references: 18399937
references: Mol Microbiol. 2010 Aug;77(4):1009-20
references: 20572935
references: Food Microbiol. 2011 Oct;28(7):1266-74
references: 21839375
references: Cell Microbiol. 2008 Jul;10(7):1413-20
references: 18373633
references: Nat Rev Microbiol. 2013 Mar;11(3):157-68
references: 23353768
references: Nat Rev Microbiol. 2010 Sep;8(9):623-33
references: 20676145
references: Int J Food Microbiol. 2014 Jul 2;181:19-27
references: 24801271
references: Appl Environ Microbiol. 2004 Nov;70(11):6887-91
references: 15528558
references: J Bacteriol. 2011 Feb;193(3):631-9
references: 21131488
references: Genes Dev. 2008 Apr 1;22(7):945-53
references: 18381896
references: Proc Natl Acad Sci U S A. 2010 Feb 2;107(5):2230-4
references: 20080671
references: Proc Natl Acad Sci U S A. 2012 Apr 24;109(17):6502-7
references: 22493266
references: Environ Microbiol. 2010 Sep;12(9):2385-97
references: 20636374
references: Proc Natl Acad Sci U S A. 2013 Aug 13;110(33):13600-5
references: 23904481
references: Trends Biochem Sci. 2007 May;32(5):217-24
references: 17412596
references: PLoS One. 2014 Jan 31;9(1):e87532
references: 24498128
references: Clin Microbiol Rev. 2010 Apr;23(2):382-98
references: 20375358
references: Int J Food Microbiol. 2000 Sep 25;60(2-3):117-35
references: 11016602
references: Environ Microbiol. 2012 Aug;14(8):2233-46
references: 22540344
references: J Bacteriol. 1999 Mar;181(5):1664-72
references: 10049401
references: Res Microbiol. 2013 Jun;164(5):382-9
references: 23562948
references: J Bacteriol. 2012 Jun;194(11):2781-90
references: 22328672
references: J Bacteriol. 2011 Sep;193(18):4821-31
references: 21742882
references: Appl Environ Microbiol. 2009 May;75(9):2861-8
references: 19251901
references: PLoS Pathog. 2012;8(6):e1002744
references: 22685403
references: J Bacteriol. 1999 Nov;181(22):7065-9
references: 10559173