Study type: Medical/biological study (experimental study)

Effects of extremely low-frequency electromagnetic fields on Helicobacter pylori biofilm. med./bio.

Published in: Curr Microbiol 2010; 60 (6): 412-418

Aim of study (acc. to author)

To study the effects of exposure to extremely low frequency electromagnetic fields both on biofilm formation and on mature biofilms of bacterium Helicobacter pylori (i.e. bacterical cultures and two day old biofilms).

Background/further details

Helicobacter pylori is a 2.5-3 µm spiral gram-negative rod. Under adverse conditions the characteristic rod shape is transformed into persistent coccoid forms.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 2 days

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 2 days
Exposure setup
Exposure source
Setup 450 mm long cylindrical solenoid with an inner diameterr of 170 mm and 180 turns of copper wire, placed vertically in an incubator; field homogeneity 1 % in the center of the solenoid; cells placed on a non-magnetic support in the center of the solenoid
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The extremely low frequency electromagnetic fields affected the bacterial population during the biofilm formation displaying significant differences in cell viability (decrease under exposure) as well as in morphological types measured by the prevalence of spiral forms. In contrast, in mature biofilms no significant differences were found when compared to the controls. The biofilm cell mass was significantly reduced in exposed cultures in both experimental conditions (i.e. mature biofilms and cell cultures), i.e. the extremely low frequency electromagnetic field exposure inhibited the biofilm formation and reduced cell adhesion. No changes in DNA patterns (genotype) were recorded, whereas a modulation in amiA gene expression (higher levels under sham exposure) was detected.
In conclusion, an exposure of Helicobacter pylori biofilm to extremely low frequency electromagnetic fields induced phenotypic changes (bacterial morphology) and decreased the cell adhesion. Thus, the Helicobacter pylori balance is disturbed by the electromagnetic field exposure reducing the bacterium's capability to protect itself.

Study character:

Study funded by

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