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
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. email@example.com
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. firstname.lastname@example.org
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
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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