Protective Capacities of Cell Surface-Associated Proteins of Streptococcus Suis Mutants Deficient in Divalent Cation-Uptake Regulators

Microbiology. 2009 May;155(Pt 5):1580-1587. doi: 10.1099/mic.0.026278-0. Epub 2009 Apr 16.


Many cell surface-associated, divalent cation-regulated proteins are immunogenic, and some of them confer protection against the bacterial species from which they are derived. In this work, two Streptococcus suis divalent cation uptake regulator genes controlling zinc/manganese and iron uptake (adcR and fur, respectively) were inactivated in order to study the protective capacities of their cell surface-associated proteins. The results obtained showed overexpression of a set of immunogenic proteins (including members of the pneumococcal histidine triad family previously reported to confer protection against streptococcal pathogens) in S. suis adcR mutant cell surface extracts. Likewise, genes encoding zinc transporters, putative virulence factors and a ribosomal protein paralogue related to zinc starvation appeared to be derepressed in this mutant strain. Moreover, protection assays in mice showed that although neither adcR- nor fur-regulated cell surface-associated proteins were sufficient to confer protection in mice, the combination of both adcR- and fur-regulated cell surface-associated proteins is able to confer significant protection (50 %, P=0.038) against a challenge to mice vaccinated with them.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / immunology
  • Biological Transport
  • Cations, Divalent / metabolism*
  • Female
  • Gene Expression Regulation, Bacterial
  • Humans
  • Membrane Proteins / genetics
  • Membrane Proteins / immunology*
  • Mice
  • Mice, Inbred BALB C
  • Mutation*
  • Repressor Proteins / genetics*
  • Repressor Proteins / immunology
  • Streptococcal Infections / immunology*
  • Streptococcal Infections / microbiology
  • Streptococcus suis / genetics
  • Streptococcus suis / immunology*
  • Transcription Factors / genetics
  • Transcription Factors / immunology*


  • Bacterial Proteins
  • Cations, Divalent
  • Membrane Proteins
  • Repressor Proteins
  • Transcription Factors
  • ferric uptake regulating proteins, bacterial