Abstract
The present study examines the efficacy of a high strength pulsed magnetic field (PMF) towards bacterial inactivation in vitro, without compromising eukaryotic cell viability. The differential response of prokaryotes [. Staphylococcus aureus (MRSA), Staphylococcus epidermidis, and Escherichia coli], and eukaryotes [C2C12 mouse myoblasts and human mesenchymal stem cells, hMSCs] upon exposure to varying PMF stimuli (1-4. T, 30 pulses, 40. ms pulse duration) is investigated.Among the prokaryotes, ~. 60% and ~. 70% reduction was recorded in the survival of staphylococcal species and E. coli, respectively at 4. T PMF as evaluated by colony forming unit (CFU) analysis and flow cytometry. A 2-5 fold increase in intracellular ROS (reactive oxygen species) levels suggests oxidative stress as the key mediator in PMF induced bacterial death/injury. The 4. T PMF treated staphylococci also exhibited longer doubling times. Both TEM and fluorescence microscopy revealed compromised membranes of PMF exposed bacteria. Under similar PMF exposure conditions, no immediate cytotoxicity was recorded in C2C12 mouse myoblasts and hMSCs, which can be attributed to the robust resistance towards oxidative stress. The ion interference of iron containing bacterial proteins is invoked to analytically explain the PMF induced ROS accumulation in prokaryotes. Overall, this study establishes the potential of PMF as a bactericidal method without affecting eukaryotic viability. This non-invasive stimulation protocol coupled with antimicrobial agents can be integrated as a potential methodology for the localized treatment of prosthetic infections.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 276-289 |
| Number of pages | 14 |
| Journal | Bioelectrochemistry |
| Volume | 106 |
| DOIs | |
| State | Published - Dec 1 2015 |
| Externally published | Yes |
Bibliographical note
Funding Information:This work was supported by the Department of Science and Technology ( DSTO 1210 ) and “Translational Center on Biomaterials for orthopaedic and dental applications” sponsored by Department of Biotechnology (DBT), Government of India. We thank the Sir Dorabji Tata Centre for Tropical Diseases for providing us S. aureus (MRSA, USA 300 strain) and the National Centre for Biological Sciences, Bangalore for providing the E. coli K12 wild type strain and C2C12 mouse myoblast cell line. We thank Aditya Roy Choudhury and V. Venkatraman from the Department of Physics, IISc for helping us install the pulse magnet used for the experiments. We are grateful to members of the IISc central FACS facility and TEM facility for helping in acquiring biological data. We also thank Greeshma T (CeNSE, IISc) for helping with the cell culture experiments. Also, one of the authors, Sunil Kumar B (09/079 (2501)/2011-EMR-I dt. 16-11-2011) acknowledges the Council for Scientific and Industrial Research (CSIR) for providing scholarship during the period of study.
Publisher Copyright:
© 2015 Elsevier B.V.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
Keywords
- Eukaryotes
- Flow cytometry
- PMF
- Prokaryotes
- Pulsed magnetic field
- Reactive oxygen species (ROS)
