CcpA Coordinates Growth/Damage Balance for Streptococcus pyogenes Pathogenesis

Sci Rep. 2018 Sep 24;8(1):14254. doi: 10.1038/s41598-018-32558-0.

Abstract

To achieve maximum fitness, pathogens must balance growth with tissue damage, coordinating metabolism and virulence factor expression. In the gram-positive bacterium Streptococcus pyogenes, the DNA-binding transcriptional regulator Carbon Catabolite Protein A (CcpA) is a master regulator of both carbon catabolite repression and virulence, suggesting it coordinates growth/damage balance. To examine this, two murine models were used to compare the virulence of a mutant lacking CcpA with a mutant expressing CcpA locked into its high-affinity DNA-binding conformation (CcpAT307Y). In models of acute soft tissue infection and of long-term asymptomatic mucosal colonization, both CcpA mutants displayed altered virulence, albeit with distinct growth/damage profiles. Loss of CcpA resulted in a diminished ability to grow in tissue, leading to less damage and early clearance. In contrast, constitutive DNA-binding activity uncoupled the growth/damage relationship, such that high tissue burdens and extended time of carriage were achieved, despite reduced tissue damage. These data demonstrate that growth/damage balance can be actively controlled by the pathogen and implicate CcpA as a master regulator of this relationship. This suggests a model where the topology of the S. pyogenes virulence network has evolved to couple carbon source selection with growth/damage balance, which may differentially influence pathogenesis at distinct tissues.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / genetics*
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation, Bacterial
  • Mice
  • Promoter Regions, Genetic
  • Protein Binding
  • Streptococcal Infections / genetics*
  • Streptococcal Infections / microbiology
  • Streptococcus pyogenes / genetics*
  • Streptococcus pyogenes / metabolism
  • Streptococcus pyogenes / pathogenicity
  • Virulence / genetics

Substances

  • Bacterial Proteins
  • CcpA protein, Streptococcus pyogenes
  • DNA-Binding Proteins