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.

Electromagnetic biology and medicine · 2015 · Harm · Low evidence

← Research stream

HarmLow evidencePaper 4558

Bacterial cultures exposed to sinusoidal homogeneous ELF-EMF at 2 or 4 mT across 20, 40, and 50 Hz showed statistically significant decreases in CFU compared with non-exposed controls, particularly at longer exposure times. The maximum inhibition was reported…

Study snapshot

PublicationElectromagnetic biology and medicine · 2015

Study typein_vitro

Reported directionHarm

Evidence ratingLow

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).

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typein_vitro

Effect directionharm

PopulationStaphylococcus aureus and Escherichia coli O157:H7 cultures in broth media

Sample sizeNot supplied

ExposureELF · 1, 2, 4, and 6 h

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Outcomes measured

Bacterial growth (colony forming units, CFU)
Colony forming capability/inhibition vs non-exposed controls

Limitations

Sample size not reported in abstract
Only two bacterial strains tested
In vitro broth/agar conditions may not generalize beyond the experimental setting
Exposure characterization limited to magnetic flux density, frequency, and time (other parameters not described)

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": "ELF",
    "source": null,
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "1, 2, 4, and 6 h"
  },
  "population": "Staphylococcus aureus and Escherichia coli O157:H7 cultures in broth media",
  "sample_size": null,
  "outcomes": [
    "Bacterial growth (colony forming units, CFU)",
    "Colony forming capability/inhibition vs non-exposed controls"
  ],
  "main_findings": "Bacterial cultures exposed to sinusoidal homogeneous ELF-EMF at 2 or 4 mT across 20, 40, and 50 Hz showed statistically significant decreases in CFU compared with non-exposed controls, particularly at longer exposure times. The maximum inhibition was reported at 4 mT, 20 Hz for 6 h (95.2% for S. aureus; 85% for E. coli).",
  "effect_direction": "harm",
  "limitations": [
    "Sample size not reported in abstract",
    "Only two bacterial strains tested",
    "In vitro broth/agar conditions may not generalize beyond the experimental setting",
    "Exposure characterization limited to magnetic flux density, frequency, and time (other parameters not described)"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "ELF-EMF",
    "extremely low-frequency electromagnetic fields",
    "sinusoidal homogeneous field",
    "magnetic intensity",
    "2 mT",
    "4 mT",
    "20 Hz",
    "40 Hz",
    "50 Hz",
    "exposure time",
    "Staphylococcus aureus",
    "Escherichia coli O157:H7",
    "colony forming units",
    "CFU",
    "Mueller-Hinton Agar"
  ],
  "suggested_hubs": []
}

AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.3109/15368378.2013.853671
PubMed: 24279632

Read the original paper →

Related papers

← Back to the Research Library