scholarly journals Global transcriptional analysis of acid-inducible genes in Streptococcus mutans: multiple two-component systems involved in acid adaptation

Microbiology ◽  
2009 ◽  
Vol 155 (10) ◽  
pp. 3322-3332 ◽  
Author(s):  
Yongxing Gong ◽  
Xiao-Lin Tian ◽  
Tara Sutherland ◽  
Gary Sisson ◽  
Junni Mai ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Expression Profiles ◽  
Acid Tolerance ◽  
Transcriptional Analysis ◽  
Acidic Ph ◽  
Acid Adaptation ◽  
Component Systems ◽  
Two Component ◽  
Tolerance Response ◽  
Two Component Systems

Streptococcus mutans in dental biofilms is regularly exposed to cycles of acidic pH during the ingestion of fermentable dietary carbohydrates. The ability of S. mutans to tolerate low pH is crucial for its virulence and pathogenesis in dental caries. To better understand its acid tolerance mechanisms, we performed genome-wide transcriptional analysis of S. mutans in response to an acidic pH signal. The preliminary results showed that adaptation of S. mutans to pH 5.5 induced differential expression of nearly 14 % of the genes in the genome, including 169 upregulated genes and 108 downregulated genes, largely categorized into nine functional groups. One of the most interesting findings was that the genes encoding multiple two-component systems (TCSs), including CiaHR, LevSR, LiaSR, ScnKR, Hk/Rr1037/1038 and ComDE, were upregulated during acid adaptation. Real-time qRT-PCR confirmed the same trend in the expression profiles of these genes at pH 5.5. To determine the roles of these transduction systems in acid adaptation, mutants with a deletion of the histidine-kinase-encoding genes were constructed and assayed for the acid tolerance response (ATR). The results revealed that inactivation of each of these systems resulted in a mutant that was impaired in ATR, since pre-exposure of these mutants to pH 5.5 did not induce the same level of protection against lethal pH levels as the parent did. A competitive fitness assay showed that all the mutants were unable to compete with the parent strain for persistence in dual-strain mixed cultures at acidic pH, although, with the exception of the mutant in liaS, little effect was observed at neutral pH. The evidence from this study suggests that the multiple TCSs are required for S. mutans to orchestrate its signal transduction networks for optimal adaptation to acidic pH.

scholarly journals Multiple Two-Component Systems of Streptococcus mutans Regulate Agmatine Deiminase Gene Expression and Stress Tolerance

2009 ◽  
Vol 191 (23) ◽  
pp. 7363-7366 ◽  
Author(s):  
Yaling Liu ◽  
Robert A. Burne
Keyword(s):  
Gene Expression ◽  
Stress Tolerance ◽  
Streptococcus Mutans ◽  
Thermal Stresses ◽  
Low Ph ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems ◽  
Agmatine Deiminase

ABSTRACT Induction of the agmatine deiminase system (AgDS) of Streptococcus mutans requires agmatine and is optimal at low pH. We show here that the VicRK, ComDE, and CiaRH two-component systems influence AgDS gene expression in response to acidic and thermal stresses.

scholarly journals PepO is a target of the two-component systems VicRK and CovR required for systemic virulence of Streptococcus mutans

Virulence ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 521-536
Author(s):  
Lívia A. Alves ◽  
Tridib Ganguly ◽  
Érika N. Harth-Chú ◽  
Jessica Kajfasz ◽  
José A. Lemos ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems

scholarly journals Multiple Two-Component Systems Modulate Alkali Generation in Streptococcus gordonii in Response to Environmental Stresses

2009 ◽  
Vol 191 (23) ◽  
pp. 7353-7362 ◽  
Author(s):  
Yaling Liu ◽  
Robert A. Burne
Keyword(s):  
Acid Tolerance ◽  
Low Ph ◽  
Arginine Deiminase ◽  
Streptococcus Gordonii ◽  
Anaerobic Conditions ◽  
Environmental Signals ◽  
Ph Values ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems

ABSTRACT The oral commensal Streptococcus gordonii must adapt to constantly fluctuating and often hostile environmental conditions to persist in the oral cavity. The arginine deiminase system (ADS) of S. gordonii enables cells to produce, ornithine, ammonia, CO2, and ATP from arginine hydrolysis, augmenting the acid tolerance of the organism. The ADS genes are substrate inducible and sensitive to catabolite repression, mediated through ArcR and CcpA, respectively, but the system also requires low pH and anaerobic conditions for optimal activation. Here, we demonstrate that the CiaRH and ComDE two-component systems (TCS) are required for low-pH-dependent expression of ADS genes in S. gordonii. Further, the VicRK TCS is required for optimal ADS gene expression under anaerobic conditions and enhances the sensitivity of the operon to repression by oxygen. The known anaerobic activator of the ADS, Fnr-like protein (Flp), appeared to act independently of the Vic TCS. Mutants of S. gordonii lacking components of the CiaRH, ComDE, or VicRK grew more slowly in acidified media and were more sensitive to killing at lethal pH values and to agents that induce oxidative stress. This study provides the first evidence that TCS can regulate the ADS of bacteria in response to specific environmental signals and reveals some notable differences in the contribution of CiaRH, ComDE, and VicRK to viability and stress tolerance between the oral commensal S. gordonii and the oral pathogen Streptococcus mutans.

scholarly journals Involvement of the Novel Two-Component NsrRS and LcrRS Systems in Distinct Resistance Pathways against Nisin A and Nukacin ISK-1 in Streptococcus mutans

2013 ◽  
Vol 79 (15) ◽  
pp. 4751-4755 ◽  
Author(s):  
Miki Kawada-Matsuo ◽  
Yuichi Oogai ◽  
Takeshi Zendo ◽  
Junichi Nagao ◽  
Yukie Shibata ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Abc Transporter ◽  
The Novel ◽  
Content Type ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems

ABSTRACTThe novel two-component systems NsrRS and LcrRS are individually associated with resistance against the distinct lantibiotics nisin A and nukacin ISK-1 inStreptococcus mutans. NsrRS regulates the expression of NsrX, which is associated with nisin A binding, and LcrRS regulates the expression of the ABC transporter LctFEG.

scholarly journals Analysis of Two-Component Systems in Group B Streptococcus Shows That RgfAC and the Novel FspSR Modulate Virulence and Bacterial Fitness

mBio ◽  
2014 ◽  
Vol 5 (3) ◽  
Author(s):  
Cristina Faralla ◽  
Matteo M. Metruccio ◽  
Matteo De Chiara ◽  
Rong Mu ◽  
Kathryn A. Patras ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Transcriptional Analysis ◽  
Transcriptional Responses ◽  
Component Systems ◽  
Two Component ◽  
Bacterial Fitness ◽  
Two Component Systems ◽  
Group B

ABSTRACTGroup BStreptococcus(GBS), in the transition from commensal organisms to pathogens, will encounter diverse host environments and, thus, require coordinated control of the transcriptional responses to these changes. This work was aimed at better understanding the role of two-component signal transduction systems (TCS) in GBS pathophysiology through a systematic screening procedure. We first performed a complete inventory and sensory mechanism classification of all putative GBS TCS by genomic analysis. Five TCS were further investigated by the generation of knockout strains, andin vitrotranscriptome analysis identified genes regulated by these systems, ranging from 0.1% to 3% of the genome. Interestingly, two sugar phosphotransferase systems appeared to be differentially regulated in the TCS-16 knockout strain (TCS loci were numbered in order of their appearance on the chromosome), suggesting an involvement in monitoring carbon source availability. High-throughput analysis of bacterial growth on different carbon sources showed that TCS-16 was necessary for the growth of GBS on fructose-6-phosphate. Additional transcriptional analysis provided further evidence for a stimulus-response circuit where extracellular fructose-6-phosphate leads to autoinduction of TCS-16, with concomitant dramatic upregulation of the adjacent operon, which encodes a phosphotransferase system. The TCS-16-deficient strain exhibited decreased persistence in a model of vaginal colonization. All mutant strains were also characterized in a murine model of systemic infection, and inactivation of TCS-17 (also known as RgfAC) resulted in hypervirulence. Our data suggest a role for the previously unknown TCS-16, here named FspSR, in bacterial fitness and carbon metabolism during host colonization, and the data also provide experimental evidence for TCS-17/RgfAC involvement in virulence.IMPORTANCETwo-component systems have been evolved by bacteria to detect environmental changes, and they play key roles in pathogenicity. A comprehensive analysis of TCS in GBS has not been performed previously. In this work, we classify 21 TCS and present evidence for the involvement of two specific TCS in GBS virulence and colonizationin vivo. Although pinpointing specific TCS stimuli is notoriously difficult, we used a combination of techniques to identify two systems with different effects on GBS pathogenesis. For one of the systems, we propose that fructose-6-phosphate, a metabolite in glycolysis, is sufficient to induce a regulatory response involving a sugar transport system. Our catalogue and classification of TCS may guide further studies into the role of TCS in GBS pathogenicity and biology.

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