The mutacins of <i>Streptococcus mutans</i>: regulation and ecology

Merritt, Justin; Qi, Fengxia

doi:10.1111/j.2041-1014.2011.00634.x

Cited by 162 publications

(187 citation statements)

References 79 publications

(169 reference statements)

Supporting

Mentioning

182

Contrasting

Order By: Relevance

“…Genetic competence, the ability to internalize exogenous DNA, is considered an important attribute of S. mutans for its establishment, persistence, nutrient acquisition, and genome diversification (11,32). In S. mutans, it has been established that CSP and sigX-inducing peptide (XIP) activate competence in S. mutans (33,34).…”

Section: Resultsmentioning

confidence: 99%

Effects of Arginine on Streptococcus mutans Growth, Virulence Gene Expression, and Stress Tolerance

Chakraborty

Burne

2017

Appl Environ Microbiol

View full text Add to dashboard Cite

Streptococcus mutans is a common constituent of oral biofilms and a primary etiologic agent of human dental caries. The bacteria associated with dental caries have potent abilities to produce organic acids from dietary carbohydrates and to grow and metabolize in acidic conditions. By contrast, many commensal bacteria produce ammonia through the arginine deiminase system (ADS), which moderates the pH of oral biofilms. Arginine metabolism by the ADS is a significant deterrent to the initiation and progression of dental caries. In this study, we observed how exogenously provided L-arginine affects the growth, the virulence properties, and the tolerance of environmental stresses of S. mutans. Supplementation with 1.5% arginine (final concentration) had an inhibitory effect on the growth of S. mutans in complex and chemically defined media, particularly when cells were exposed to acid or oxidative stress. The genes encoding virulence factors required for attachment/accumulation (gtfB and spaP), bacteriocins (nlmA, nlmB, nlmD, and cipB), and the sigma factor required for competence development (comX) were downregulated during growth with 1.5% arginine. Deep sequencing of RNA (RNA-Seq) comparing the transcriptomes of S. mutans growing in chemically defined media with and without 1.5% arginine revealed differential expression of genes encoding ATP-binding cassette transporters, metal transporters, and constituents required for survival, metabolism, and biofilm formation. Therefore, the mechanisms of action by which arginine inhibits dental caries include direct adverse effects on multiple virulence-related properties of the most common human dental caries pathogen.IMPORTANCE Metabolism of the amino acid arginine by the arginine deiminase system (ADS) of certain oral bacteria raises the pH of dental plaque and provides a selective advantage to health-associated bacteria, thereby protecting the host from dental caries (cavities). Here, we examine the effects of arginine on the cavitycausing bacterium Streptococcus mutans. We find that arginine negatively impacts the growth, the pathogenic potential, and the tolerance of environmental stresses in a way that is likely to compromise the ability of S. mutans to cause disease. Using genetic and genomic techniques, multiple mechanisms by which arginine exerts its influence on virulence-related properties of S. mutans are discovered. This report demonstrates that a primary mechanism of action by which arginine inhibits the initiation and progression of dental caries may be by reducing the pathogenic potential of S. mutans.

show abstract

Section: Resultsmentioning

confidence: 99%

Effects of Arginine on Streptococcus mutans Growth, Virulence Gene Expression, and Stress Tolerance

Chakraborty

Burne

2017

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…There is evidence that peptides produced by S. mutans (Jarosz et al, 2009) and Enterococcus faecalis (Cruz et al, 2013) are inhibitory to filamentation by C. albicans. The ComCDE systems in S. gordonii, S. pneumoniae and S. mutans function as QS autoregulatory control systems, modulating gene expression patterns in different ways for the three streptococcal species (Vickerman et al, 2007;Mashburn-Warren et al, 2010;Son et al, 2012;Merritt & Qi, 2012). Since S. gordonii and C. albicans form fully integrated dual species biofilm communities (Dutton et al, 2014) we investigated the possible role of the ComCDE system in their regulation.…”

Section: Discussionmentioning

confidence: 99%

Streptococcus gordonii comCDE (competence) operon modulates biofilm formation with Candida albicans

et al. 2015

View full text Add to dashboard Cite

“…However, the mutacin V immunity protein (SMU.925) was slightly downregulated. In addition to the CSP-driven mutacin synthesis controlled by the ComDE TCS, bacteriocin synthesis is regulated by three other TCS, HdrRM, BrsRM and VicRK (Merritt and Qi, 2012). The HdrRM (SMU.1854 and SMU.1855) and BrsRM (SMU.2080 and SMU.2081) systems did not show significant changes in gene expression.…”

Section: Cultivation Mediummentioning

confidence: 96%

Cross-feeding and interkingdom communication in dual-species biofilms of Streptococcus mutans and Candida albicans

et al. 2014

View full text Add to dashboard Cite

Polymicrobial biofilms are of large medical importance, but relatively little is known about the role of interspecies interactions for their physiology and virulence. Here, we studied two human pathogens co-occuring in the oral cavity, the opportunistic fungus Candida albicans and the caries-promoting bacterium Streptococcus mutans. Dual-species biofilms reached higher biomass and cell numbers than mono-species biofilms, and the production of extracellular polymeric substances (EPSs) by S. mutans was strongly suppressed, which was confirmed by scanning electron microscopy, gas chromatography-mass spectrometry and transcriptome analysis. To detect interkingdom communication, C. albicans was co-cultivated with a strain of S. mutans carrying a transcriptional fusion between a green fluorescent protein-encoding gene and the promoter for sigX, the alternative sigma factor of S. mutans, which is induced by quorum sensing signals. Strong induction of sigX was observed in dual-species biofilms, but not in single-species biofilms. Conditioned media from mixed biofilms but not from C. albicans or S. mutans cultivated alone activated sigX in the reporter strain. Deletion of comS encoding the synthesis of the sigX-inducing peptide precursor abolished this activity, whereas deletion of comC encoding the competence-stimulating peptide precursor had no effect. Transcriptome analysis of S. mutans confirmed induction of comS, sigX, bacteriocins and the downstream late competence genes, including fratricins, in dual-species biofilms. We show here for the first time the stimulation of the complete quorum sensing system of S. mutans by a species from another kingdom, namely the fungus C. albicans, resulting in fundamentally changed virulence properties of the caries pathogen.

show abstract

The mutacins of Streptococcus mutans: regulation and ecology

Cited by 162 publications

References 79 publications

Effects of Arginine on Streptococcus mutans Growth, Virulence Gene Expression, and Stress Tolerance

Effects of Arginine on Streptococcus mutans Growth, Virulence Gene Expression, and Stress Tolerance

Streptococcus gordonii comCDE (competence) operon modulates biofilm formation with Candida albicans

Cross-feeding and interkingdom communication in dual-species biofilms of Streptococcus mutans and Candida albicans

Contact Info

Product

Resources

About