Abstract
The CiaR/H two-component system is involved in regulating virulence and competence in Streptococcus pneumoniae. The system is known to regulate many genes, including that for high-temperature requirement A (HtrA). This gene has been implicated in the ability of the pneumococcus to colonize the nasopharynx of infant rats. We reported previously that deletion of the gene for HtrA made the pneumococcal strains much less virulent in mouse models, less able to grow at higher temperatures, and more sensitive to oxidative stress. In this report, we show that the growth phenotype as well as sensitivity to oxidative stress of Delta ciaR mutant was very similar to that of a Delta htrA mutant and that the expression of the HtrA protein was reduced in a ciaR-null mutant. Both the in vitro phenotype and the reduced virulence of Delta ciaR mutant could be restored by increasing the expression of HtrA.
Original language | English |
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Pages (from-to) | 5258-66 |
Number of pages | 9 |
Journal | Journal of Bacteriology |
Volume | 186 |
Issue number | 16 |
DOIs | |
Publication status | Published - Aug 2004 |
Keywords
- Adaptation, Physiological
- Animals
- Bacterial Proteins
- Colony Count, Microbial
- Disease Models, Animal
- Gene Deletion
- Gene Expression Regulation, Bacterial
- Genes, Bacterial
- Genetic Complementation Test
- Heat-Shock Proteins
- Hydrogen Peroxide
- Mice
- Oxidants
- Oxidative Stress
- Periplasmic Proteins
- Pneumococcal Infections
- Protein Kinases
- Serine Endopeptidases
- Signal Transduction
- Streptococcus pneumoniae
- Survival Analysis
- Temperature
- Virulence
- Virulence Factors