title: 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.
abstract: 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 4 mT 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 °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).
authors.affiliation: Department of Biomedical Technologies, Graduate School of Natural and Applied Sciences and.
authors.forename: Ece
authors.initials: E
authors.lastname: Bayır
authors.forename: Eyüp
authors.initials: E
authors.lastname: Bilgi
authors.forename: Aylin
authors.initials: A
authors.lastname: Şendemir-Ürkmez
authors.forename: E Esin
authors.initials: EE
authors.lastname: Hameş-Kocabaş
mesh_terms: D004307:Dose-Response Relationship, Radiation; D004574:Electromagnetic Fields; D019453:Escherichia coli O157 / Q000254:growth & development* / Q000528:radiation effects*; D013211:Staphylococcus aureus / Q000254:growth & development* / Q000528:radiation effects*; D013997:Time Factors
keywords: Bacteria; Escherichia coli; Staphylococcus aureus; extremely low-frequency electromagnetic field