Identification of a bile-induced exopolysaccharide required for Salmonella biofilm formation on gallstone surfaces.
Salmonella enterica serovar Typhi can establish a chronic, asymptomatic infection of the human gallbladder, suggesting that this bacterium utilizes novel mechanisms to mediate enhanced colonization and persistence in a bile-rich environment. Gallstones are one of the most important risk factors for developing carriage, and we have previously demonstrated that salmonellae form biofilms on human gallstones in vitro. Thus, we hypothesize that bile-induced biofilms on gallstone surfaces promote gallbladder colonization and maintenance of the carrier state. A colanic acid/cellulose S. enterica serovar Typhimurium double mutant formed a mature biofilm on gallstones in a test tube assay and in a new, gallstone-independent assay using cholesterol-coated Eppendorf tubes. These data suggest the presence of an unidentified exopolysaccharide necessary for mature biofilm development and demonstrate specific binding affinity between salmonellae and cholesterol. Our experiments indicate that the Salmonella O-antigen capsule (yihU-yshA and yihV-yihW) is a crucial determinant in gallstone and cholesterol biofilms but that expression of this exopolysaccharide is not necessary for binding to glass or plastic. Real-time PCR revealed that growth in bile resulted in upregulation of the O-antigen capsule-encoding operon in an agfD-independent manner. Thus, the O-antigen capsule genes are bile induced, and the capsule produced by the enzymes of this operon is specifically required for biofilm formation on cholesterol gallstones. These studies provide new therapeutic targets for preventing asymptomatic serovar Typhi gallbladder carriage.
Crawford
Robert W
RW
Center for Microbial Interface Biology and Department of Molecular Virology, Immunology, and Medical Genetics, The Ohio State University, Columbus, Ohio 43210, USA.
Gibson
Deanna L
DL
Kay
William W
WW
Gunn
John S
JS
D016667:Bacterial Capsules / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001646:Bile / Q000378:metabolism / Q000382:microbiology*; D018441:Biofilms / Q000254:growth & development*; D002784:Cholesterol / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005109:Extracellular Matrix / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D042882:Gallstones / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008855:Microscopy, Electron, Scanning; D019081:O Antigens / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012480:Salmonella Infections / Q000378:metabolism; D012485:Salmonella typhi / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D019081:O Antigens; D014157:Transcription Factors; C408132:agfD protein, Salmonella typhimurium; D002784:Cholesterol
Annu Rev Microbiol. 1995;49:711-45
8561477
Cell Microbiol. 2007 Apr;9(4):1039-49
17381433
Infect Immun. 2002 Jan;70(1):121-6
11748172
Infect Immun. 2002 May;70(5):2640-9
11953406
Mol Microbiol. 2005 Feb;55(4):1183-95
15686563
J Surg Oncol. 2006 Jun 15;93(8):633-9
16724347
FEMS Immunol Med Microbiol. 2004 Jun 1;41(2):177-85
15145463
Annu Rev Microbiol. 1996;50:285-315
8905082
Infect Immun. 2003 Dec;71(12):7154-8
14638807
Mol Plant Microbe Interact. 2007 Sep;20(9):1083-91
17849711
Infect Immun. 2000 Dec;68(12):6763-9
11083793
J Bacteriol. 2006 Nov;188(22):7722-30
17079680
J Bacteriol. 2005 Nov;187(21):7417-24
16237025
Am J Gastroenterol. 1992 Sep;87(9):1198-9
1519582
Cell Microbiol. 2002 Jun;4(6):315-28
12067317
News Physiol Sci. 1999 Feb;14:24-29
11390813
J Bacteriol. 2007 Mar;189(5):1489-95
17189373
J Bacteriol. 2005 May;187(9):3214-26
15838049
FEMS Microbiol Rev. 2005 Sep;29(4):625-51
16102595
Genetics. 1983 Nov;105(3):517-37
6357943
Bull World Health Organ. 2004 May;82(5):346-53
15298225
Mol Microbiol. 2006 Jan;59(1):193-201
16359328
Mol Microbiol. 2008 Apr;68(1):173-85
18333886
J Bacteriol. 2003 Sep;185(18):5398-407
12949092
J Bacteriol. 1999 Mar;181(5):1508-14
10049382
J Infect Dis. 1982 Dec;146(6):724-6
7142746
Infect Immun. 2000 Mar;68(3):1491-7
10678965
Infect Immun. 2001 Jul;69(7):4681-5
11402016
Infect Immun. 1999 Apr;67(4):1614-22
10084994
Can J Microbiol. 1987 Dec;33(12):1080-90
2451553
Infect Immun. 2007 Apr;75(4):1946-53
17261615
Proc Natl Acad Sci U S A. 2000 Jun 6;97(12):6640-5
10829079
Mol Microbiol. 1999 Mar;31(5):1307-19
10200953
Infect Immun. 2005 Mar;73(3):1797-810
15731081
Infect Immun. 2007 May;75(5):2626-9
17296762
Proc Natl Acad Sci U S A. 2006 Jan 3;103(1):141-6
16373510
Am J Gastroenterol. 2000 Mar;95(3):784-7
10710075
Infect Immun. 1995 Sep;63(9):3642-8
7642302
Proc Natl Acad Sci U S A. 2005 Feb 22;102(8):3028-33
15699331
Microbiology (Reading). 2003 Oct;149(Pt 10):2847-2857
14523117
World J Gastroenterol. 2006 Apr 14;12(14):2181-6
16610018
Mol Microbiol. 1998 Apr;28(2):249-64
9622351
J Bacteriol. 2000 Jun;182(12):3593-6
10852895