Antibacterial activity of magnetite isolated and associated with electromagnetic fields on resistant Escherichia coli
Bacterial resistance, magnetite, magnetic field.
The increase in bacterial resistance in the years and the WHO stimulus for the development of innovative antimicrobial therapies, many studies have evaluated the possible antibacterial effects of magnetic fields and their possibility of application, due to the fact that it is a non-pharmacological therapy and, therefore, exempt from the molecular effects of the resistance phenomenon. At the same time, as magnetic nanoparticles with superparamagnetic properties, especially magnetite (Fe3O4), although widely exploited as a local-specific drug delivery system associated with an external magnetic field, it has other interesting properties that are studied regarding bacteria. In this sense, the present work evaluated as intrinsic antibacterial properties of magnetite nanoparticles associated or not with an external electromagnetic field (70 mT, 10 Hz). The tests on kanamycin-resistant Escherichia coli DH5α revealed bacteriostatic effects with decreased growth, important morphological changes in the cell wall and increased zeta potential of the bacterial suspension, when exposed for 24 hours. These results reveal an important antimicrobial potential, both for magnetite alone, and in combination with the magnetic field. In addition, magnetite nanoparticles have been shown to potentiate the antibiotic's inhibitory effect, making it possible to decrease the necessary dose of the drug to obtain the same degree of bacterial inhibition and this points to a second use option, as an adjunct to antibiotic therapy. Additional tests are inoculated to prove the importance of the observed effects.