Catabolite control protein A of Streptococcus suis type 2 contributes to sugar metabolism and virulence

J Microbiol. 2012 Dec;50(6):994-1002. doi: 10.1007/s12275-012-2035-3. Epub 2012 Dec 30.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • Carbohydrate Metabolism*
  • Cell Adhesion / genetics
  • Female
  • Gene Deletion
  • Gene Expression Regulation, Bacterial
  • Gene Order
  • Mice
  • Molecular Sequence Data
  • Sequence Alignment
  • Streptococcus suis / genetics
  • Streptococcus suis / metabolism*
  • Streptococcus suis / pathogenicity*
  • Virulence / genetics
  • alpha-Galactosidase / metabolism
  • beta-Glucosidase / metabolism

Substances

  • Bacterial Proteins
  • beta-Glucosidase
  • alpha-Galactosidase