Related Experiment Video
Updated: Aug 6, 2026
The Synergistic Effect of Visible Light and Gentamycin on Pseudomona aeruginosa Microorganisms
Published on: July 2, 2013
Dosimetry of pulsed magnetic field towards attaining bacteriostatic effect on Enterococcus faecalis: Implications for
Sharmistha Naskar1,2,3, Chandan4, Divya Baskaran5
1Laboratory for Biomaterials, Materials Research Centre, Indian Institute of Science, Bangalore, India.
Aim:
To examine in a laboratory setting the efficacy of moderate to high strength magnetic fields, as a potential bacteriostatic stimulus, against Enterococcus faecalis, one of the causative agents for infection during root canal treatments.
Methodology:
Four different strengths (1, 2, 3 and 4 T) of the pulsed magnetic field (PMF) were applied in thirty repetitions to bacterial suspension. A pickup coil setup was used to measure the electromotive force induced inside the bacterial suspensions. The optical density (OD) was monitored over time (for 16 h 40 min) during the post-treatment period to assess bacterial growth. Along with the change in OD values, live/dead assay, membrane depolarization study, atomic force microscopy (AFM), scanning electron microscopy (SEM) and reactive oxygen species (ROS) assay on selected samples were studied to evaluate the effect of PMFs. All results were analysed using one-way ANOVA followed by post hoc Tukey test and considered significant at p < .05. Regression analysis (at a confidence of 95%, α = 0.05) was performed on the bacterial growth and membrane depolarization studies to determine progressive changes of the outcomes.
Results:
The peak value of the induced electromotive force was recorded as 0.25 V, for the 4 T magnetic field pulse with a pulse width of 16 ms. There was a significant arrest of bacterial cell growth after an exposure to PMFs of 1 T, 3 T and 4 T (ANOVA score: F (4, 495) =395.180 at p = .05). The image-based qualitative results of the live/dead assay using fluorescence microscopy techniques indicated that an exposure to higher PMFs (3 T/ 4 T) induced a bacteriostatic effect in a longer post-exposure timescale. Evidence of altered membrane potential within the 2 h of exposure to 4 T PMF was supported by the incidence of elevated ROS. For the ROS assay, a significant difference occurred for 4 T exposed samples (ANOVA score: calculated F (1, 3) =20.2749 at p = .05). SEM and AFM observations corroborated with the outcomes, by portraying significant membrane damage.
Conclusion:
In a laboratory setting, PMFs with higher magnitudes (3 T and 4 T) were capable of inducing bacteriostatic effects on E. faecalis.
Insights
High-strength pulsed magnetic fields (PMFs) demonstrated bacteriostatic effects against Enterococcus faecalis, a common cause of root canal infections. These findings suggest PMFs could be a novel therapeutic approach for endodontic treatments.
Area of Science:
- Biophysics
- Microbiology
- Endodontics
Background:
- Enterococcus faecalis is a significant pathogen in root canal infections.
- Novel therapeutic strategies are needed to combat endodontic infections.
- Pulsed magnetic fields (PMFs) have potential antimicrobial properties.
Purpose of the Study:
- To evaluate the bacteriostatic efficacy of varying strengths of PMFs against Enterococcus faecalis in vitro.
- To investigate the underlying mechanisms of PMF-induced bacterial inhibition.
Main Methods:
- Bacterial suspensions of Enterococcus faecalis were exposed to pulsed magnetic fields (PMFs) of 1, 2, 3, and 4 Tesla.
- Bacterial growth was monitored via optical density.
- Live/dead assays, membrane depolarization, reactive oxygen species (ROS) generation, atomic force microscopy (AFM), and scanning electron microscopy (SEM) were employed to assess cellular damage and effects.
Main Results:
- PMF exposure at 1T, 3T, and 4T significantly inhibited Enterococcus faecalis growth.
- Higher PMF strengths (3T and 4T) induced a sustained bacteriostatic effect.
- PMF exposure, particularly at 4T, led to increased ROS production, membrane depolarization, and significant membrane damage observed via SEM and AFM.
Conclusions:
- Pulsed magnetic fields of 3T and 4T demonstrate significant bacteriostatic potential against Enterococcus faecalis in a laboratory setting.
- The findings suggest PMFs could be a promising adjunctive therapy for managing root canal infections.
More Related Videos
09:01Magnetic-, Acoustic-, and Optical-Triple-Responsive Microbubbles for Magnetic Hyperthermia and Pothotothermal Combination Cancer Therapy
Published on: May 22, 2020
11:47Evaluation of the Efficacy of Organic Peroxyacids for Eradicating Dairy Biofilms Using an Approach Combining Static and Dynamic Methods
Published on: December 9, 2022
