Journal: Frontiers in Microbiology

Article Title: A GntR Family Transcription Factor in Streptococcus mutans Regulates Biofilm Formation and Expression of Multiple Sugar Transporter Genes

doi: 10.3389/fmicb.2018.03224

Figure Lengend Snippet: Deletion of stsR decreases S. mutans biofilm formation at early stage. S. mutans was cultured in BM supplemented with 1% sucrose for 6, 12, 24, and 48 h. The biofilm biomass was determined by CV staining method. Data from three biological replicates were averaged, and the statistical significance between the stsR mutant, wild-type, and complement strain was determined by Student’s t -test. Error bars represent standard deviations based on results from at least three biological replicates. ∗∗ Indicates a significance of P < 0.01.

Article Snippet: According to the National Center for Biotechnology Information (NCBI) S. mutans genome annotation, the function of the majority of the differentially expressed genes (DEGs) are unknown.

Techniques: Cell Culture, Staining, Mutagenesis

Journal: Frontiers in Microbiology

Article Title: A GntR Family Transcription Factor in Streptococcus mutans Regulates Biofilm Formation and Expression of Multiple Sugar Transporter Genes

doi: 10.3389/fmicb.2018.03224

Figure Lengend Snippet: Determination of growth curves of S. mutans UA159, S. mutans Δ stsR , and Δ stsR/pDL278-stsR . S. mutans UA159, S. mutans Δ stsR , and Δ stsR/pDL278-stsR strains were cultivated in BHI to mid-exponential phase and then diluted into (A) fresh BHI broth or (B) TV base medium supplemented with either 10 mM (limiting) or 100 mM (excess) sucrose, glucose, or lactose. Growth curves were monitored with a Multiskan Spectrum (Thermo, Multiskan Go, United States), and the OD 600 was measured in 1 h intervals. (A) For CFU counts, after diluted, the bacteria were cultured at 37°C for 1, 4, 8, and 12 h. Then bacterial suspension was serially diluted in BHI and plated on BHI agar plates. CFU values were calculated after the plates were incubated anaerobically at 37°C for 48 h. Error bars represent standard deviations based on results from at least three biological replicates.

Article Snippet: According to the National Center for Biotechnology Information (NCBI) S. mutans genome annotation, the function of the majority of the differentially expressed genes (DEGs) are unknown.

Techniques: Bacteria, Cell Culture, Suspension, Incubation

Journal: Frontiers in Microbiology

Article Title: A GntR Family Transcription Factor in Streptococcus mutans Regulates Biofilm Formation and Expression of Multiple Sugar Transporter Genes

doi: 10.3389/fmicb.2018.03224

Figure Lengend Snippet: Deletion of stsR decreases the amount of glucans in S. mutans biofilm. The amounts of (A) water insoluble glucans and (B) water soluble glucans in the biofilms of S. mutans UA159, S. mutans Δ stsR , and complement strain were quantified using the phenol-sulfuric acid method and calculated according to the standard curve. Error bars represent standard deviations based on results from at least three biological replicates. ∗∗ Indicates a significance of P < 0.01.

Article Snippet: According to the National Center for Biotechnology Information (NCBI) S. mutans genome annotation, the function of the majority of the differentially expressed genes (DEGs) are unknown.

Techniques:

Journal: Frontiers in Microbiology

Article Title: A GntR Family Transcription Factor in Streptococcus mutans Regulates Biofilm Formation and Expression of Multiple Sugar Transporter Genes

doi: 10.3389/fmicb.2018.03224

Figure Lengend Snippet: Scanning electron microscopy analysis reveals altered biofilm morphology and decreased biofilm extracellular matrix of S. mutans Δ stsR . Biofilms formed by S. mutans UA159, S. mutans Δ stsR , and complement strain were grown for 6 h and then scanned by scanning electron microscopy (SEM) under (A) 1000× magnification, (B) 5000× magnification, and (C) 20000× magnification.

Article Snippet: According to the National Center for Biotechnology Information (NCBI) S. mutans genome annotation, the function of the majority of the differentially expressed genes (DEGs) are unknown.

Techniques: Electron Microscopy

Journal: Frontiers in Microbiology

Article Title: A GntR Family Transcription Factor in Streptococcus mutans Regulates Biofilm Formation and Expression of Multiple Sugar Transporter Genes

doi: 10.3389/fmicb.2018.03224

Figure Lengend Snippet: Biofilm structure and EPS distribution of S. mutans strains observed by confocal microscopy. (A) Double-labeling of 6 h S. mutans biofilms. Green indicates bacteria (SYTO 9), and red indicates EPS (Alexa Fluor 647). Images were taken at 60× magnification. The three-dimensional reconstruction of the biofilms and the quantification of EPS/bacteria biomass were performed with IMARIS 7.0.0. (B) The ratio of EPS to bacteria at different heights was quantified with COMSTAT. Results are the average of five randomly selected positions of each sample and are presented as mean ± standard deviation. (C–E) Quantification of S. mutans UA159 (C) , S. mutans Δ stsR (D) , and Δ stsR/pDL278-stsR (E) biofilms. EPS biomass was performed with COMSTAT at different heights. Results are the average of five randomly selected positions of each sample and are presented as mean ± standard deviation.

Article Snippet: According to the National Center for Biotechnology Information (NCBI) S. mutans genome annotation, the function of the majority of the differentially expressed genes (DEGs) are unknown.

Techniques: Confocal Microscopy, Labeling, Bacteria, Standard Deviation

Journal: Frontiers in Microbiology

Article Title: A GntR Family Transcription Factor in Streptococcus mutans Regulates Biofilm Formation and Expression of Multiple Sugar Transporter Genes

doi: 10.3389/fmicb.2018.03224

Figure Lengend Snippet: Quantitative RT-PCR assays for the relative expression levels of gtfs and ftf genes in S. mutans UA159, S. mutans Δ stsR , and Δ stsR/pDL278-stsR . The experiments were carried out as described in Experimental procedures. All target genes were amplified using specific primers. Different gene expressions were normalized to the levels of 16S rRNA gene transcripts, and the folds of expression change were calculated.

Article Snippet: According to the National Center for Biotechnology Information (NCBI) S. mutans genome annotation, the function of the majority of the differentially expressed genes (DEGs) are unknown.

Techniques: Quantitative RT-PCR, Expressing, Amplification

Journal: Frontiers in Microbiology

Article Title: A GntR Family Transcription Factor in Streptococcus mutans Regulates Biofilm Formation and Expression of Multiple Sugar Transporter Genes

doi: 10.3389/fmicb.2018.03224

Figure Lengend Snippet: The differentially expressed sugar transport system operons in S. mutans Δ stsR . The genetic organization of differentially expressed gene clusters that were associated with sugar transport systems in S. mutans Δ stsR . Upregulated genes are colored red, and downregulated genes are colored green.

Article Snippet: According to the National Center for Biotechnology Information (NCBI) S. mutans genome annotation, the function of the majority of the differentially expressed genes (DEGs) are unknown.

Techniques:

Journal: Applied and Environmental Microbiology

Article Title: Raffinose Induces Biofilm Formation by Streptococcus mutans in Low Concentrations of Sucrose by Increasing Production of Extracellular DNA and Fructan

doi: 10.1128/AEM.00869-17

Figure Lengend Snippet: The function of the polysaccharide synthase genes in biofilm formation in TSBr. (A) The amount of biofilm formed by the deletion mutants of the gene encoding polysaccharide synthase in TSBr. (B) CLSM analysis of the biofilm formed in TSBr. The cells in the biofilm were stained with the LIVE/DEAD BacLight bacterial viability kit for 30 min. Representative images from three independent experiments are presented. (C) An aggregation assay of the bacterial cells. The roles of eDNA and fructan in cell aggregation were examined by mimicking the extracellular matrix synthesized in TSBr. Five micrograms per milliliter genomic DNA of UA159 and/or 250 μg/ml commercial inulin was added to 3 ml of cell suspension, which was grown in BHI and adjusted to an OD600 of 1.5 with aggregation buffer. The data are presented as the means ± SD of the results from three independent experiments. The asterisks indicate a significant difference between two groups (Student's t test, P < 0.05).

Article Snippet: We used genomic DNA isolated from S. mutans UA159 using the DNeasy blood and tissue kit (Qiagen, Venlo, The Netherlands) and inulin (Nacalai Tesque, Kyoto, Japan) to mimic the main components of the biofilm matrix formed in TSBr.

Techniques: Staining, Synthesized, Suspension