The effects of different intensities, frequencies and exposure times of extremely low-frequency electromagnetic fields on the growth of Staphylococcus aureus and Escherichia coli O157: H7


Bayır E. , Bılgı E., Sendemir-Urkmez A. , Hames E. E.

ELECTROMAGNETIC BIOLOGY AND MEDICINE, cilt.34, ss.14-18, 2015 (SCI İndekslerine Giren Dergi) identifier identifier identifier

  • Cilt numarası: 34
  • Basım Tarihi: 2015
  • Doi Numarası: 10.3109/15368378.2013.853671
  • Dergi Adı: ELECTROMAGNETIC BIOLOGY AND MEDICINE
  • Sayfa Sayıları: ss.14-18

Özet

The impact of different types of extremely low-frequency electromagnetic fields (ELF-EMF) on the growth of Staphylococcus aureus and Escherichia coli O157:H7 was investigated. The cultures of bacteria in broth media were exposed to sinusoidal homogenous ELF-EMF with 2 and 4mT magnetic intensities. Each intensity for each bacteria was combined with three different frequencies (20, 40 and 50 Hz), and four different exposure times (1, 2, 4 and 6 h). A cell suspension of each experiment was diluted for the appropriate range and inoculated to Mueller-Hinton Agar (MHA) plates after exposure to ELF-EMF. The number of colony forming units (CFU) of both strains was obtained after incubation at 37 degrees C for 24 h. Data were statistically evaluated by one-way analysis of variance (ANOVA), statistical significance was described at p<0.05 and data were compared with their non-exposed controls. Magnetic intensity, frequency and exposure time of ELF-EMFs changed the characteristic responses for both microorganisms. Samples exposed to ELF-EMF showed a statistically significant decrease compared to their controls in colony forming capability, especially at long exposure times. An exposure to 4 mT-20 Hz ELF-EMF of 6 h produced maximum inhibition of CFU compared to their controls for both microorganisms (95.2% for S. aureus and 85% for E. coli).