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

Growth inhibition of Staphylococcus aureus induced by low‐frequency electric and electromagnetic fields

“…Gerencser et al [1962] demonstrated reduced bacterial growth of Staphylococci and Serratia marsecens following exposure to static magnetic fields. However, Kohno et al [2000] could not detect any inhibition in E. coli exposed to static magnetic fields. Nevertheless, they observed a decreased growth rate and growth maximum number of S. mutans and Staphylococcus aureus under anaerobic conditions.…”

“…Even a small reduction in the number of bacteria at the beginning of the growth process greatly affects the geometrical progression of the growth process [Stra s ak et al, 2002;Fojt et al, 2004]. Bacteriostatic effects induced by static magnetic fields may also be explained by radicals such as hydroxyl, chloride and hypochloride [Kohno et al, 2000].…”

The Effects of Rotating Magnetic Field on Growth Rate, Cell Metabolic Activity and Biofilm Formation by Staphylococcus Aureus and Escherichia Coli

“…SMF; 100 mT; exposure time 30, 60, 120, 240 min the MF exposure for 30 min had no effect on bacterial cell density; the longer MF exposure (120, 240 min) caused growth inhibition [28] SMF; 7-11 Hz; exposure time 220 min the MF had no effect on DNA damage; the MF had stimulating effect on cell growth [29] SMF; 5, 17 and 50 mT; exposure time 1, 2, 3 and 4 h the MF negatively influences the growth; the MF caused an increase in dehydrogenase activity and higher intracellular ATP concentrations [30] SMF; 10 mT; 50 Hz; exposure time 1h the MF had no effect on bacterial morphology [1] SMF; 2 mT; 50 Hz; exposure time 6, 16 h the MF caused a decrease in the cell growth [31] SMF; 5.2-6.1 T; exposure time 30 h the MF increased suppression of cell death; the MF stimulated growth [32] SMF; 50 Hz; 1 mT; exposure time 8 min, 2, 5 and 15 h the MF had no effect on cell viability regardless of exposure time [33] SMF; 5.2-6.1 T; exposure time 12 h the MF caused a suppressive effect on the cell death rate [34] SMF; 45-3500 mT; exposure time 60 min the MF caused a decrease in the number of CFU; the MF influenced on cell surface damage [35] SMF; 300 mT; exposure time 50 h the MF had no effect on the growth; the MF stimulated transposition activity [36] SMF; 2.7-10 mT; 50 Hz; exposure time 0-12 min the MF affected the bacteria E. coli; the MF was not bacteriostatic; the MF had no effect on the metabolism of the bacteria; the MF killed a part of bacteria exposed [37] SMF; 5, 10 and 13 T; exposure time 24 h the MF had no effect on mutation frequency in thymine synthesis genes [38] E. coli; S. aureus SMF; 10 mT; 50 Hz; exposure time < 30 min the MF caused a decrease in the cell viability; the MF caused a decrease in CFU [20] DCMF; 0.5-4 T; exposure time 30-120 min the MF had no influence on growth [21] SMF; 30-100 mT; exposure time 30 h the MF had no effect on growth [22] homogeneous SMF (400 mT); inhomogeneous SMF; (1.2-47.7 T); exposure time 10, 30, 50, 1440 min the MF had no effect on growth [39] MF; up to 10 mT; 50 Hz; exposure time up to 24 min the MF caused a decrease in optical densities of bacterial cultures [40] SMF (DCMF); 10 T; exposure time 5-60 min the MF altered the components and structure of nucleic acid, protein, and fatty acids [37] S. aureus SMF; 50-20.000 Gauss the MF had no effect on growth, when the field strength increased there were a slight growth inhibition EMF; 20 Hz; 5 mT; exposure time 24 h the MF had no effect on growth on gel-like medium; the MF caused a decrease in growth in fluid medium [4] AC -alternating current; ACMF -alternating current magnetic field; DC -direct current; DCMF -direct current magnetic field; EF -electric field; EMF -electromagn...…”

“…It is agreed upon, that in the near future, this information can contribute to improve the effectiveness of treatment and prophylaxis of many serious bacterial infections [20][21][22]. It can be assumed that in the future the RMF could also be used as a relatively cheap and easy-touse agent for modulating functional and pathogenic parameters of bacteria, and it could be applied to the medi- …”

Metabolic effects of static magnetic fields on streptococcus pyogenes

“…Bacteria represent simple unicellular organisms and thus a base model for studying metabolic impact of magnetic fields. Previous studies which utilised bacterial species to determine effects of magnetic fields on different parameters include that by Stansell et al [2001], which showed that exposure of Escherichia coli to static magnetic fields can result in increased antibiotic resistance of intermediately-resistant cells, and Kohno et al [2000], which demonstrated decreased cell viability at flux densities as low as 30 mT in Staphylococcus aureus and Streptococcus mutans under anaerobic conditions. No change was detected in this same study at the same field strength for E. coli, however, or for any of the above named species under aerobic conditions [Kohno et al, 2000].…”