title: Carbohydrate availability regulates virulence gene expression in Streptococcus suis.
abstract: Streptococcus suis is a major bacterial pathogen of young pigs causing worldwide economic problems for the pig industry. S. suis is also an emerging pathogen of humans. Colonization of porcine oropharynx by S. suis is considered to be a high risk factor for invasive disease. In the oropharyngeal cavity, where glucose is rapidly absorbed but dietary α-glucans persist, there is a profound effect of carbohydrate availability on the expression of virulence genes. Nineteen predicted or confirmed S. suis virulence genes that promote adhesion to and invasion of epithelial cells were expressed at higher levels when S. suis was supplied with the α-glucan starch/pullulan compared to glucose as the single carbon source. Additionally the production of suilysin, a toxin that damages epithelial cells, was increased more than ten-fold when glucose levels were low and S. suis was growing on pullulan. Based on biochemical, bioinformatics and in vitro and in vivo gene expression studies, we developed a biological model that postulates the effect of carbon catabolite repression on expression of virulence genes in the mucosa, organs and blood. This research increases our understanding of S. suis virulence mechanisms and has important implications for the design of future control strategies including the development of anti-infective strategies by modulating animal feed composition.
authors.affiliation: Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands; Department of Medical Microbiology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: M Laura
authors.initials: ML
authors.lastname: Ferrando
authors.affiliation: Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: van Baarlen
authors.affiliation: Oral Biotechnology Laboratory, University of Cagliari, Cagliari, Italy.
authors.forename: Germano
authors.initials: G
authors.lastname: Orrù
authors.affiliation: Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands.
authors.forename: Rosaria
authors.initials: R
authors.lastname: Piga
authors.affiliation: NIZO Food Research B.V., Ede, The Netherlands.
authors.forename: Roger S
authors.initials: RS
authors.lastname: Bongers
authors.affiliation: NIZO Food Research B.V., Ede, The Netherlands.
authors.forename: Michiel
authors.initials: M
authors.lastname: Wels
authors.affiliation: Central Veterinary Institute, Animal Sciences Group, Wageningen University, Lelystad, The Netherlands.
authors.forename: Astrid
authors.initials: A
authors.lastname: De Greeff
authors.affiliation: Central Veterinary Institute, Animal Sciences Group, Wageningen University, Lelystad, The Netherlands.
authors.forename: Hilde E
authors.initials: HE
authors.lastname: Smith
authors.affiliation: Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands.
authors.forename: Jerry M
authors.initials: JM
authors.lastname: Wells
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004847:Epithelial Cells / Q000382:microbiology; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005936:Glucans / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006460:Hemolysin Proteins / Q000096:biosynthesis / Q000378:metabolism; D006801:Humans; D007785:Lactose / Q000378:metabolism; D008954:Models, Biological; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D009960:Oropharynx / Q000382:microbiology; D013290:Streptococcal Infections / Q000378:metabolism / Q000382:microbiology / Q000662:veterinary*; D017011:Streptococcus suis / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D013552:Swine; D013553:Swine Diseases / Q000378:metabolism / Q000382:microbiology*; D014312:Trisaccharides / Q000378:metabolism; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D005936:Glucans; D006460:Hemolysin Proteins; D014312:Trisaccharides; C104760:suilysin; C008317:maltotriose; C009109:pullulan; D005947:Glucose; D007785:Lactose