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AIM To assess potential function of each two-component signal transduction system in the expression of Streptococcus mutans virulence properties. METHODS AND RESULTS For each two-component system (TCS), the histidine kinase-encoding gene was inactivated by a polymerase chain reaction (PCR)-based deletion strategy and the effects of gene disruption on the(More)
The Streptococcus thermophilus virulent pac-type phage 2972 was isolated from a yogurt made in France in 1999. It is a representative of several phages that have emerged with the industrial use of the exopolysaccharide-producing S. thermophilus strain RD534. The genome of phage 2972 has 34,704 bp with an overall G+C content of 40.15%, making it the shortest(More)
Streptococcal competence-stimulating peptides (CSPs) were once thought to passively communicate population density in a process known classically as quorum sensing. However, recent evidence has shown that these peptides may also be inducible 'alarmones,' capable of conveying sophisticated messages in a population including the induction of altruistic(More)
The induction of genetic competence is a strategy used by bacteria to increase their genetic repertoire under stressful environmental conditions. Recently, Streptococcus pneumoniae has been shown to co-ordinate the uptake of transforming DNA with fratricide via increased expression of the peptide pheromone responsible for competence induction. Here, we(More)
The signal recognition particle (SRP)-translocation pathway is conserved in all three domains of life and delivers membrane and secretory proteins to the cytoplasmic membrane or endoplasmic reticulum. We determined the requirement in the cariogenic oral pathogen Streptocococcus mutans of the three universally conserved elements of the SRP pathway:(More)
Streptococcus mutans is considered one of the main causative agents of human dental caries. Cell-cell communication through two-component signal transduction systems (TCSTS) plays an important role in the pathogenesis of S. mutans. One of the S. mutans TCSTS, ComDE, controls both competence development and biofilm formation. In this study, we showed that(More)
Streptococcus mutans, a normal inhabitant of dental plaque, is considered a primary etiological agent of dental caries. Its main virulence factors are acidogenicity and aciduricity, the abilities to produce acid and to survive and grow at low pH, respectively. Metabolic processes are finely regulated following acid exposure in S. mutans. Proteome analysis(More)
Streptococcus mutans, a member of the human indigenous oral microbiome, produces a quorum-sensing peptide called the competence-stimulating peptide (CSP) pheromone. We previously demonstrated that S. mutans expresses its CSP pheromone under specific stresses and responds to high levels of CSP by inducing cell death in a fraction of the bacterial population.(More)
AIMS To identify the genes regulated by RR11, the regulator of the Streptococcus mutans HK/RR11 two-component system. METHODS AND RESULTS The S. mutans RR11-encoding gene was inactivated, and the effects of gene disruption on the cell's ability to form biofilms under stresses and acquire extracellular DNA were tested. Biofilm was reduced in cells lacking(More)
Bacteria are considered "social" organisms able to communicate with one another using small hormone-like molecules (pheromones) in a process called quorum-sensing (QS). These signaling molecules increase in concentration as a function of bacterial cell density. For most human pathogens, QS is critical for virulence and biofilm formation, and the opportunity(More)