Journal: Biomolecules

Article Title: Mechanism of Action of Zinc Oxide Nanoparticles as an Antibacterial Agent Against Streptococcus mutans

doi: 10.3390/biom15121660

Figure Lengend Snippet: Primers used for real-time qPCR of the indicated S. mutans genes [ 50 , 55 ].

Article Snippet: The cariogenic Streptococcus mutans UA159 strain (ATCC 700610) was used as the bacterial model strain in our study.

Techniques:

Journal: Biomolecules

Article Title: Mechanism of Action of Zinc Oxide Nanoparticles as an Antibacterial Agent Against Streptococcus mutans

doi: 10.3390/biom15121660

Figure Lengend Snippet: ZnO NPs prevent the planktonic growth and biofilm formation of S. mutans . ( A ) Planktonic growth of S. mutans following a 24 h incubation with indicated ZnO NP concentrations. ( B ) Metabolic activity of biofilms formed after a 24 h incubation with ZnO NPs as determined by MTT assay. ( C ) Biofilm biomass after a 24 h incubation with ZnO NPs as determined by crystal violet staining. The control bacteria incubated for 24 h in the absence of ZnO NPs was set to 100%. Data are presented as mean ± SD of triplicate experiments. * p < 0.05 and ** p < 0.005 compared to control.

Article Snippet: The cariogenic Streptococcus mutans UA159 strain (ATCC 700610) was used as the bacterial model strain in our study.

Techniques: Incubation, Activity Assay, MTT Assay, Staining, Control, Bacteria

Journal: Biomolecules

Article Title: Mechanism of Action of Zinc Oxide Nanoparticles as an Antibacterial Agent Against Streptococcus mutans

doi: 10.3390/biom15121660

Figure Lengend Snippet: Bacteriostatic and bactericidal effect of ZnO NPs on S. mutans . ( A ) CFU counts of S. mutans at various time points after exposure to indicated concentrations of ZnO NPs. ( B ) ATP levels in S. mutans at various time points after being exposed to the indicated concentrations of ZnO NPs, relative to the initial levels at time 0 which was set to 1. Data are presented as mean ± SD of triplicate experiments. * p < 0.05 and ** p < 0.005 compared to control bacteria at each time point.

Article Snippet: The cariogenic Streptococcus mutans UA159 strain (ATCC 700610) was used as the bacterial model strain in our study.

Techniques: Control, Bacteria

Journal: Biomolecules

Article Title: Mechanism of Action of Zinc Oxide Nanoparticles as an Antibacterial Agent Against Streptococcus mutans

doi: 10.3390/biom15121660

Figure Lengend Snippet: Effect of ZnO NPs on the pH of S. mutans cultures over a 30 h incubation period. The pH of the culture medium was monitored at different time points to evaluate acid production in the presence of various concentrations of ZnO NPs (0.5 and 1 mg/mL) compared with the untreated control. ** p < 0.005 compared to control bacteria.

Article Snippet: The cariogenic Streptococcus mutans UA159 strain (ATCC 700610) was used as the bacterial model strain in our study.

Techniques: Incubation, Control, Bacteria

Journal: Biomolecules

Article Title: Mechanism of Action of Zinc Oxide Nanoparticles as an Antibacterial Agent Against Streptococcus mutans

doi: 10.3390/biom15121660

Figure Lengend Snippet: ZnO NPs induce membrane damage and cytoplasmic leakage in S. mutans. S. mutans cultures were treated with the indicated concentrations of ZnO NPs for 6 h, followed by SYTO 9/PI live/dead staining and analysis by flow cytometry. The percentage of PI + and SYTO 9 low are presented. The graph presents the mean ±SD of three replicates. * p < 0.05, ** p < 0.005 compared to control bacteria.

Article Snippet: The cariogenic Streptococcus mutans UA159 strain (ATCC 700610) was used as the bacterial model strain in our study.

Techniques: Membrane, Staining, Flow Cytometry, Control, Bacteria

Journal: Biomolecules

Article Title: Mechanism of Action of Zinc Oxide Nanoparticles as an Antibacterial Agent Against Streptococcus mutans

doi: 10.3390/biom15121660

Figure Lengend Snippet: High-resolution scanning electron microscopy (HR-SEM) images of planktonic growing S. mutans following 2 h incubation with increasing concentrations of ZnO NPs. ( A ) Control (untreated); ( B ) 0.1 mg/mL ZnO NPs; ( C ) 0.25 mg/mL ZnO NPs; ( D ) 0.5 mg/mL ZnO NPs; ( E ) 1 mg/mL ZnO NPs. Images were acquired double-blinded at ×20,000 magnification. ( F ) Summary of EDS analysis of Zn/C content in 3 arbitrary sites of each sample as presented in . * p < 0.05, ** p < 0.005.

Article Snippet: The cariogenic Streptococcus mutans UA159 strain (ATCC 700610) was used as the bacterial model strain in our study.

Techniques: Electron Microscopy, Incubation, Control

Journal: Biomolecules

Article Title: Mechanism of Action of Zinc Oxide Nanoparticles as an Antibacterial Agent Against Streptococcus mutans

doi: 10.3390/biom15121660

Figure Lengend Snippet: ZnO NPs increase ROS production in S. mutans . S. mutans was incubated in HBSS supplemented with 1% glucose, 50 µM Luminol and 4 U/mL HRP in the absence or presence of the indicated concentrations of ZnO NPs, and the luminescence was measured every minute for 125 min. Reactive oxygen species (ROS) are converted into radicals by horseradish peroxidase (HRP), which then oxidize luminol to emit luminescence. ( A ) Untreated bacteria (no ZnO NPs) showed moderate luminescence due to basic ROS production, while treatment with ZnO NPs induced a concentration-dependent increase in luminescence, with the strongest response observed at 1 mg/mL. Background (1 mg/mL ZnO) showed negligible luminescence, confirming that the luminescence originated from the bacteria. ( B ) Quantification of total ROS production during the 125 min test period expressed as the area under the curve (AUC ± SD) calculated from data presented in panel A. The AUC values demonstrate a dose-dependent increase in ROS levels in response to ZnO NP treatment. * p < 0.05, ** p <0.005 compared to control bacteria.

Article Snippet: The cariogenic Streptococcus mutans UA159 strain (ATCC 700610) was used as the bacterial model strain in our study.

Techniques: Incubation, Bacteria, Concentration Assay, Control

Journal: Biomolecules

Article Title: Mechanism of Action of Zinc Oxide Nanoparticles as an Antibacterial Agent Against Streptococcus mutans

doi: 10.3390/biom15121660

Figure Lengend Snippet: Effect of ZnO NPs on the membrane potential of S. mutans. Membrane potential was assessed using the potentiometric dye DiOC2(3). Green (530 nm) and red (610/620 nm) fluorescence intensities were measured by flow cytometry after a 30 min exposure to increasing ZnO NP concentrations (0–10 mg/mL). Data are presented as mean ± SD of triplicate experiments. a: p < 0.05 when comparing red fluorescence intensity with green fluorescent intensity. b: p < 0.05 when comparing the fluorescent intensity of treated cells with that of untreated control bacteria.

Article Snippet: The cariogenic Streptococcus mutans UA159 strain (ATCC 700610) was used as the bacterial model strain in our study.

Techniques: Membrane, Fluorescence, Flow Cytometry, Control, Bacteria

Journal: Biomolecules

Article Title: Mechanism of Action of Zinc Oxide Nanoparticles as an Antibacterial Agent Against Streptococcus mutans

doi: 10.3390/biom15121660

Figure Lengend Snippet: Effect of ZnO on EPS production by S. mutans. S. mutans was exposed to the indicated concentrations of ZnO NPs for 2, 4 and 6 h, and then 10 µL of the bacterial suspension was spotted on Conge Red agar plates for a 24 h incubation. The black area around the bacteria, indicative of EPS production, was measured by ImageJ software. EPS production was measured after 2, 4, and 6 h of exposure to increasing ZnO concentrations (0–10 mg/mL). Data are presented as mean ± SD of triplicate experiments. * p < 0.05, ** p < 0.005 compared to control bacteria.

Article Snippet: The cariogenic Streptococcus mutans UA159 strain (ATCC 700610) was used as the bacterial model strain in our study.

Techniques: Suspension, Incubation, Bacteria, Software, Control

Journal: Biomolecules

Article Title: Mechanism of Action of Zinc Oxide Nanoparticles as an Antibacterial Agent Against Streptococcus mutans

doi: 10.3390/biom15121660

Figure Lengend Snippet: Effect of ZnO NPs on gene expression in S. mutans . Relative expression levels of selected genes were measured by real-time qPCR after 2 h exposure to 0.25 mg/mL ZnO NPs compared with untreated control. Expression levels were normalized to the housekeeping gene gyrA and fold-changes calculated using the 2 −ΔΔCt method. ( A ) Quorum sensing–related genes. ( B ) Genes involved in regulating biofilm formation and membrane integrity. ( C ) EPS production-related genes. ( D ) Stress response and cell division-related genes. Several genes showed significant upregulation or downregulation in response to ZnO NPs, indicating that sub-inhibitory concentrations modulate stress adaptation and virulence pathways. Data are presented as mean ± SD of triplicate experiments. n = 3, ** p < 0.005 compared to control bacteria.

Article Snippet: The cariogenic Streptococcus mutans UA159 strain (ATCC 700610) was used as the bacterial model strain in our study.

Techniques: Gene Expression, Expressing, Control, Membrane, Bacteria