scholarly journals Role of the phosphoenolpyruvate-dependent glucose phosphotransferase system of Streptococcus mutans GS5 in the regulation of lactose uptake.

1984 ◽  
Vol 43 (2) ◽  
pp. 536-542 ◽  
Author(s):  
E S Liberman ◽  
A S Bleiweis
Keyword(s):  
Streptococcus Mutans ◽  
Phosphotransferase System

scholarly journals Different Roles of EIIABMan and EIIGlc in Regulation of Energy Metabolism, Biofilm Development, and Competence in Streptococcus mutans

2006 ◽  
Vol 188 (11) ◽  
pp. 3748-3756 ◽  
Author(s):  
Jacqueline Abranches ◽  
Melissa M. Candella ◽  
Zezhang T. Wen ◽  
Henry V. Baker ◽  
Robert A. Burne
Keyword(s):  
Energy Metabolism ◽  
Streptococcus Mutans ◽  
Energy Levels ◽  
Sugar Metabolism ◽  
Oral Streptococci ◽  
Phosphotransferase System ◽  
Exogenous Dna ◽  
Biofilm Development ◽  
Metabolism Gene

ABSTRACT The phosphoenolpyruvate:sugar phosphotransferase system (PTS) is the major carbohydrate transport system in oral streptococci. The mannose-PTS of Streptococcus mutans, which transports mannose and glucose, is involved in carbon catabolite repression (CCR) and regulates the expression of known virulence genes. In this study, we investigated the role of EIIGlc and EIIABMan in sugar metabolism, gene regulation, biofilm formation, and competence. The results demonstrate that the inactivation of ptsG, encoding a putative EIIGlc, did not lead to major changes in sugar metabolism or affect the phenotypes of interest. However, the loss of EIIGlc was shown to have a significant impact on the proteome and to affect the expression of a known virulence factor, fructan hydrolase (fruA). JAM1, a mutant strain lacking EIIABMan, had an impaired capacity to form biofilms in the presence of glucose and displayed a decreased ability to be transformed with exogenous DNA. Also, the lactose- and cellobiose-PTSs were positively and negatively regulated by EIIABMan, respectively. Microarrays were used to investigate the profound phenotypic changes displayed by JAM1, revealing that EIIABMan of S. mutans has a key regulatory role in energy metabolism, possibly by sensing the energy levels of the cells or the carbohydrate availability and, in response, regulating the activity of transcription factors and carbohydrate transporters.

scholarly journals Genome-wide identification of novel sRNAs in Streptococcus mutans

2021 ◽  
Author(s):  
Madeline Krieger ◽  
Justin Merritt ◽  
Rahul Raghavan
Keyword(s):  
Gene Regulation ◽  
Stress Response ◽  
Streptococcus Mutans ◽  
Oral Bacteria ◽  
Fine Tuning ◽  
Energetic Cost ◽  
Phosphotransferase System ◽  
Posttranscriptional Gene Regulation ◽  
Oral Biofilms

Streptococcus mutans is a major pathobiont involved in the development of dental caries. Its ability to utilize numerous sugars and to effectively respond to environmental stress promotes S. mutans proliferation in oral biofilms. Because of their quick action and low energetic cost, non-coding small RNAs (sRNAs) represent an ideal mode of gene regulation in stress response networks, yet their roles in oral pathogens have remained largely unexplored. We identified 15 novel sRNAs in S. mutans and show that they respond to four stress-inducing conditions commonly encountered by the pathogen in human mouth: sugar-phosphate stress, hydrogen peroxide exposure, high temperature, and low pH. To better understand the role of sRNAs in S. mutans, we further explored the function of the novel sRNA, SmsR4. Our data demonstrate that SmsR4 regulates the EIIA component of the sorbitol phosphotransferase system, which transports and phosphorylates the sugar alcohol sorbitol. The fine-tuning of EIIA availability by SmsR4 likely promotes S. mutans growth while using sorbitol as the main carbon source. Our work lays a foundation for understanding the role of sRNAs in regulating gene expression in stress response networks in S. mutans and highlights the importance of the underexplored phenomenon of posttranscriptional gene regulation in oral bacteria.

The role of intracanal medicaments in inhibition of bacteria isolated from root canals of infected primary molars

2019 ◽  
Vol 14 (1) ◽  
pp. 92
Author(s):  
Dr. Maha Abdul- Kareem Mahmood ◽  
Dr. Huda Elias Ali ◽  
Dr. Haraa Khairi Abdul-Kadher
Keyword(s):  
Antimicrobial Activity ◽  
Streptococcus Mutans ◽  
Normal Saline ◽  
Root Canal ◽  
Primary Teeth ◽  
Primary Molars ◽  
Root Canals ◽  
Etiologic Agents ◽  
Micro Organisms

Microbes are considered as the primary etiologic agents in endodontic diseases.Disinfection of the root canal is obtained by the combined effect of biomechanicalpreparation, irrigation and intra canal medicament. The aim of the present study wasto assess the antimicrobial activity of intracanal medicaments (formocresol andEndosepton) against two micro organisms (Streptococcus mutans and staphylococcusaureus) isolated from 15 necrotic pulps of primary molars indicated for pulpectomyprocedure. The samples were cultured, and purified using microbiological evaluation.Broth dilution test was performed in our study by preparing test tubes containing10 ml of BHI broth (pH. 7) which then inoculated with strains of the tested bacteriaand incubated at 37 C° for 24 h. After over night incubaction, ten fold dilution weremade in test tubes containing 9 ml of normal saline by adding 1 ml of the inoculum tothe first tube . Then from dilution 10-1 , 0.1 ml of cell suspension was added to 9.9 mlof formocresol and endosepton, then 0.1 ml was taken and spread on duplicates ofBHI agar plates at different intervals and incubated aerobically for 24 h. at 37 C°.Colonies on the plates were counted after incubation and CFU/mL (colony formingunit) was calculated. Our results indicating that there were no significant differencesbetween the intracanal medicaments, but there were high significant differencesbetween the intervals time of the study. We concluded that both materials had greatantibacterial effect against the pathogens commonly isolated from necrotic pulpaltissue of primary teeth.

Inactivation of the Streptococcus mutans fxpC Gene Confers Resistance to Xylitol, a Caries-preventive Natural Carbohydrate Sweetener

2002 ◽  
Vol 81 (6) ◽  
pp. 380-386 ◽  
Author(s):  
H. Benchabane ◽  
L.-A. Lortie ◽  
N.D. Buckley ◽  
L. Trahan ◽  
M. Frenette
Keyword(s):  
Streptococcus Mutans ◽  
Northern Blot Analysis ◽  
Regulatory Protein ◽  
Open Reading Frames ◽  
Phosphotransferase System ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Resistant Strains ◽  
Polymerase Chain ◽  
Reading Frames

Xylitol is transported by Streptococcus mutans via a constitutive phosphoenolpyruvate:fructose phosphotransferase system (PTS) composed of a IIABC protein. Spontaneous xylitol-resistant strains are depleted in constitutive fructose-PTS activity, exhibit additional phenotypes, and are associated with the caries-preventive properties of xylitol. Polymerase chain-reactions and chromosome walking were used to clone the fxp operon that codes for the constitutive fructose/xylitol-PTS. The operon contained three open reading frames: fxpA, which coded for a putative regulatory protein of the deoxyribose repressor (DeoR) family, fxpB, which coded for a 1-phosphofructokinase, and fxpC, which coded for a IIABC protein of the fructose-PTS family. Northern blot analysis revealed that these genes were co-transcribed into a 4.4-kb mRNA even in the absence of fructose. Inactivation of the fxpC gene conferred resistance to xylitol, confirming its function. The fxp operon is also present in the genomes of other xylitol-sensitive streptococci, which could explain their sensitivity to xylitol.

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