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Magnetic Therapy Research: Effects on Bacterial

Antibacterial effect of a magnetic field on Serratia marcescens and related virulence to Hordeum vulgare and Rubus fruticosus callus cells.

Piatti E, Albertini MC, Baffone W, Fraternale D, Citterio B, Piacentini MP, Dacha M, Vetrano F, Accorsi A.

Universita degli Studi di Urbino, Istituto di Chimica Biologica Giorgio Fornaini, Via Saffi 2, 61029 Urbino PU, Italy.

The exposure to a static magnetic field of 80+/-20 Gauss (8+/-2 mT) resulted in the inhibition of Serratia marcescens growth. Callus cell suspensions from Hordeum vulgare and Rubus fruticosus were also examined and only the former was found to be affected by the magnetic field, which induced a decreased viability. S. marcescens was shown to be virulent only toward H. vulgare and this virulence was reduced by the presence of the magnetic field. The modification of glutathione peroxidase activity under the different experimental conditions allowed us to speculate on the possibility of an oxidative-stress response of H. vulgare both to S. marcescens infection and magnetic field exposure. Since the control of microbial growth by physical agents is of interest for agriculture, medicine and food sciences, the investigation presented herein could serve as a starting point for future studies on the efficacy of static magnetic field as low-cost/easy-handling preservative agent.

Comp Biochem Physiol B Biochem Mol Biol. 2002 Jun;132(2):359-65.

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The effect of magnetic fields on the growth and division of the lon mutant of Escherichia coli K-12.

Stepanian RS, Barsegian AA, Alaverdian ZhR, Oganesian GG, Markosian LS, Airapetian SN.

Biophysics Center, Armenian National Academy of Science, Erevan.

It was shown that the static magnetic field (SMF) and electromagnetic field (EMF) caused inhibition of the cell division in Escherichia coli K-12 lon mutant. The low-frequency EMF 4 Hz led to the 20% survival, but EMF at 50 Hz increased the survival of cells up to 53%. After exposure to magnetic field cells lost capacity for division and grow as filaments, unable to form the colonies on the solid media.

Radiats Biol Radioecol. 2000 May-Jun;40(3):319-22.

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Effect of static magnetic field on E. coli cells and individual rotations of ion-protein complexes.

Binhi VN, Alipov YD, Belyaev IY.

General Physics Institute Russian Academy of Sciences, Moscow, Russia.

The effect of week static magnetic fields on Escherichia coli K12 AB1157 cells was studied by the method of anomalous viscosity time dependencies (AVTD). The AVTD changes were found when E. coli cells were exposed to static fields within the range from 0 to 110 microT. The dependence of the effect on the magnetic flux density had several extrema. These results were compared with theoretical predictions of the ion interference mechanism. This mechanism links the dissociation probability of ion-protein complexes to parameters of magnetic fields. The mechanism was extended to the case of rotating complexes. Calculations were made for several ions of biological relevance. The results of simulations for Ca(2+), Mg(2+), and Zn(2+) showed a remarkable consistency with experimental data. An important condition for this consistency was that all complexes rotate with the same speed approximately 18 revolutions per second (rps). This suggests that the rotation of the same carrier for all ion-protein complexes may be involved in the mechanism of response to the magnetic field. We believe that this carrier is DNA. Copyright 2001 Wiley-Liss, Inc.

Bioelectromagnetics. 2001 Feb;22(2):79-86.

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Effect of static magnetic field on growth of Escherichia coli and relative response model of series piezoelectric quartz crystal.

Zhang S, Wei W, Zhang J, Mao Y, Liu S.

College of Chemistry and Chemical Engineering, Hunan University, Changsha, PR China.

The effect of magnetic field on the growth of bacteria was studied with the series piezoelectric quartz crystal (SPQC) sensing technique. The growth situations of Escherichia coli (E. coli) in the absence and presence of different intensities of static magnetic fields were examined and analyzed. The results showed that the growth of E. coli was inhibited due to the presence of magnetic fields. By fitting frequency shift (deltaD) versus time curves according to the frequency shift response equation of SPQC, the relationships between three kinetic growth parameters, i.e., the asymptote A, the maximum specific growth rate mu(m) and lag time lambda, and magnetic field intensity were established. Based on these results, a new response model containing the magnetic field intensity was derived as: delta(f) = 167.7 (7.25 - 7.11B)/[1 + exp[4 x 2.46e(-3.97B)/(7.25 -7.1 IB)] x (4.42 + 16.46B - t) + 2]] The kinetic parameters of bacterial growth obtained from this model are close to those obtained from the logistics popular growth model, in which the concentration of the bacteria was determined by the traditional pour plate count method.

Analyst. 2002 Mar;127(3):373-7.

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Effect of static magnetic fields on bacteria: Streptococcus mutans, Staphylococcus aureus, and Escherichia coli.

Kohno M, Yamazaki M, Kimura I I, Wada M.

Application and Research Center, Analytical Instruments Division, JEOL LTD., 1-2 Musashino 3-Chome, Akishima, 196-8558, Tokyo, Japan

Biological effect of static magnetic field was investigated by using ferrite magnets to conduct a magnetic field exposure experiment on three species of bacteria: Streptococcus mutans, Staphylococcus aureus, and Escherichia coli. The effects were evaluated by culturing the bacteria and determining their growth rate, the maximum numbers of bacteria, and [3H]-thymidine incorporation. The results showed that the ferrite magnet caused strength-dependent decreases in the growth rate and growth maximum number of bacteria for S. mutans and S. aureus when cultured under anaerobic conditions, but that their growth was not inhibited under aerobic conditions. In addition, [3H]-thymidine was added after culturing each of the species of bacteria for 18 h. After that, culture was continued until 24 h, and changes in [3H]-thymidine incorporation were investigated. But no effect of the magnetic fields was detected. These findings suggested that oxygen related to growth the cases of S. mutans, S. aureus. However, no growth effects were detected on E. coli cultures.

Pathophysiology. 2000 Jul;7(2):143-148.

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Magnetic field enhancement of antibiotic activity in biofilm forming Pseudomonas aeruginosa.

Benson DE, Grissom CB, Burns GL, Mohammad SF.

Artificial Heart Research Laboratory, University of Utah, Salt Lake City, USA.

Device related infection initiated by biofilm bacteria are often difficult to resolve with antimicrobial therapy. Study results indicate that application of static magnetic fields may enhance the activity of gentamicin against biofilm forming Pseudomonas aeruginosa adherent to a polymer substrate. Results indicate a maximal reduction of 86.5 +/- 7.2% (n = 6) in the number of adherent viable bacteria compared with a control for samples exposed to a 5 gauss (G) magnetic field and gentamicin. The effect appears to be limited to magnetic fields between 5 and 20 G. Experiments using glass, Chronoflex (Polymedica, Golden, CO), Biomer (Ethicon, Somerville, NJ), and polystyrene substrate showed that the effect was independent of substrate surface. Autoradiograms from In111 uptake experiments showed that bacteria colonizing the substrate surface were significantly reduced in samples subjected to a magnetic field and gentamicin.

ASAIO J. 1994 Jul-Sep;40(3):M371-6.

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