title: Catabolite control protein A of Streptococcus suis type 2 contributes to sugar metabolism and virulence.
abstract: Catabolite control protein A (CcpA) is the major transcriptional regulator in carbon catabolite repression in several Gram-positive bacteria. We attempted to characterize the role of a CcpA homologue of Streptococcus suis type 2 in sugar metabolism and virulence. Addition of glucose or sucrose to the defined medium significantly reduced the activity of raffinose-inducible α-galactosidase, cellobiose-inducible β-glucosidase, and maltose-inducible α-glucosidase of the wild-type strain by about 9, 4, and 2-3 fold, respectively. Deletion of ccpA substantially derepressed the effects of repressing sugars on α-galactosidase or β-glucosidase activity. The ccpA deletion mutant showed reduced expression of virulence genes sly and eno (P<0.05), decreased adhesion to and invasion into endothelial cells (P<0.05), and attenuated virulence to mice with significant reduction of death rate and bacterial burden in organs, as compared to the wild-type strain. Both the in vitro and in vivo defect phenotypes were reversible by ccpA complementation. Thus, this study shows that CcpA of S. suis type 2 plays an important role in carbon catabolite repression and virulence.
authors.affiliation: Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Tang
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhang
authors.forename: Zhongyan
authors.initials: Z
authors.lastname: Lu
authors.forename: Jianshun
authors.initials: J
authors.lastname: Chen
authors.forename: Weihuan
authors.initials: W
authors.lastname: Fang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D050260:Carbohydrate Metabolism; D002448:Cell Adhesion / Q000235:genetics; D005260:Female; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D023061:Gene Order; D051379:Mice; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017011:Streptococcus suis / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics; D000519:alpha-Galactosidase / Q000378:metabolism; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D001617:beta-Glucosidase; D000519:alpha-Galactosidase